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Jharkhand Board JAC Class 10 Maths Solutions Chapter 8 Introduction to Trigonometry Ex 8.1 Textbook Exercise Questions and Answers.

JAC Board Class 10 Maths Solutions Chapter 8 Introduction to Trigonometry Exercise 8.1

Question 1.
Evaluate the following:
(i) sin 60° cos 30° + sin 30° cos 60°
(ii) 2 tan² 45° + cos² 30° – sin² 60°

Solution :
(i) sin 60° cos 30° + sin 30° cos 60°
\(\frac{\sqrt{3}}{2} \times \frac{\sqrt{3}}{2}\) + \(\frac{1}{2} \times \frac{1}{2}\)
\(\frac{3}{4}+\frac{1}{4}\) = 1

(ii) 2 tan² 45° + cos² 30° – sin² 60°
2(tan 45)² + (cos 30)² – (sin 60)²
2(1)² + (\(\frac{\sqrt{3}}{2}\))² – (\(\frac{\sqrt{3}}{2}\))² = 2

Question 2.
Choose the correct option and justify your choice:
(i) \(\frac{2 \tan 30^{\circ}}{1+\tan ^2 30^{\circ}}\)
(A) sin 60°
(B) cos 60°
(C) tan 60°
(D) sin 30°
Solution :

(ii) \(\frac{1-\tan ^2 45^{\circ}}{1+\tan ^2 45^{\circ}}\) =
(A) tan 90°
(B) 1
(C) sin 45°
(D) 0
Solution :
\(\frac{1-(-1)^2}{1+(1)^2}=\frac{0}{2}\) = 0

(iii) sin 2A = 2 sin A is true when A =
(A) 0°
(B) 30°
(C) 45°
(D) 60°
Solution :
sin 2A = sin 0° = 0
2 sin A = 2 sin 0° = 2(0) = 0.

(iv) \(\frac{2 \tan 30^{\circ}}{1-\tan ^2 30^{\circ}}\) =
(A) cos 60°
(B) sin 60°
(C) tan 60°
(D) sin 30°
Solution :

Question 3.
If tan (A + B) = \(\sqrt{3}\) and tan (A – B) = \(\frac{1}{\sqrt{3}}\), 0° < A + B ≤ 90°; A > B, find A and B.
Solution :
tan(A + B) = \(\sqrt{3}\)
tan 60° = \(\sqrt{3}\)
∴ A + B = 60°
tan (A – B) = \(\frac{1}{\sqrt{3}}\)
tan 30° = \(\frac{1}{\sqrt{3}}\)
∴ A – B = 30°
∴ \(\hat{\mathbf{A}}\) = 45°, \(\hat{\mathbf{B}}\) = 15°

A + B = 60°
45 + B = 60°
B = 60 – 45 = 15
∴ B = 15°

Question 4.
State whether the following are true or false. Justify your answer.
(i) sin (A + B) = sin A + sin B.
(ii) The value of sin θ increases as θ increases.
(iii) The value of cos θ increases as θ increases.
(iv) sin θ = cos θ for all values of θ.
(v) cot A is not defined for A = 0°.
Solution :
i) Let A = 30°, B = 60°.
sin 30° = \(\frac{1}{2}\)
sin 30 + sin 60°
sin (A + B) = sin 90° = 1
sin 60° = \(\frac{\sqrt{3}}{2}\)
\(\frac{1}{2}+\frac{\sqrt{3}}{2}\) = \(\frac{1+\sqrt{3}}{2}\)
sin (A+B) sin A + sin B
False.

iv) [θ = 0] sin 0 = 0
cos 0 = 1

θ = 30° sin 30° = \(\frac{1}{2}\)
cos 30° = \(\frac{\sqrt{3}}{2}\)

θ = 45° sin 45° = \(\frac{1}{\sqrt{2}}\)
cos 45° = \(\frac{1}{\sqrt{2}}\)

θ = 60° sin 60° = \(\frac{\sqrt{3}}{2}\)
cos 60° = \(\frac{1}{2}\)

θ = 90° sin 90° = 1
cos 90° = 0
False, because it is true only for θ = 45°.

(v) cot A = \(\frac{cos A}{sin A}\) . cot 0° = \(\frac{cos 0°}{sin 0°}\) = \(\frac{1}{0}\) = Undefined. True.

JAC Board Class 9th Social Science Solutions Geography Chapter 4 Climate

JAC Class 9th Geography Climate InText Questions and Answers 

Find Out (Page No. 27)

Question 1.
Why the houses in Rajasthan have thick walls and flat roofs?
Answer:
Rajasthan lies mostly in desert where the climate remains very hot. Due to lack of vegetation, here the sunrays fall directly on the earth. Also the winds blow very fast here. Therefore, the houses have thick walls to maintain the inner temperature of the houses and keep them cool for longer time. They have flat roofs to collect the rainwater because there is scarcity of water in Rajasthan.

Question 2.
Why is the houses in the Tarai region and in Goa & Mangalore have sloping roofs?
Answer:
The Tarai region, Goa and Mangalore are places receiving heavy rainfall throughout the year. Therefore, the houses in these regions have sloping roofs to allow the rainwater to flow down speedily. Non-accumulation of water allows sloping roofs being safe during rainy season.

Question 3.
Why houses in Assam are built on stilts?
Answer:
In Assam, the average rainfall is above 300 cm. Due to heavy rainfall throughout the year, the ground always remains wet. Stilts allow free flow of water on the ground and the houses are not flooded. Therefore, houses are built on stilts to avoid wetness and danger from poisonous reptiles living on the wet ground.

Question 4.
Why most of the World’s deserts are located in the western margins of continents in the sub-tropics ?
Answer:
Most of the world’s deserts are located in the western margins of continents in the sub-tropics because the prevailing winds in the tropics are tropical easterly winds. These winds become dry by the time they reach the western margins of the continents and so they bring no rainfall. Thus, the region becomes moisture-less which causes dry conditions leading to formation of deserts.

Activity (Page No. 38)

Question 1.
1. On the basis of the news items above, find out the names of places and the seasons described.
2. Compare the rainfall description of Chennai and Mumbai and explain the reasons for the difference.
3. Evaluate flood as a disaster with the help of a case study.
Answer:

1. Rainy season Mumbai & Chennai
   Winter Season Srinagar, Amritsar, Shimla and New Delhi.
2. Chennai receives winter rains while Mumbai monsoonal rains. In Chennai, rainfall is less than that in Mumbai.
   The main reason behind this difference is that both Mumbai and Chennai are situated in different monsoon regions.
3. Students are requested to perform the activity on themselves.

JAC Class 9th Geography Climate Textbook Questions and Answers 

Question 1.
Choose the correct answer from the four alternatives given below:
1. Which one of the following places receives the highest rainfall in the world?
(a) Silchar
(b) Mawsynram
(c) Cherrapunji
(d) Guwahati.
Answer:
(b) Mawsynram

2. The wind blowing in the Northern plains in summers is known as :
(a) Kal Baisakhi
(b) Loo
(c) Trade winds
(d) None of these
Answer:
(b) Loo

3. Which one of the following causes rainfall during winters in north-western part of India?
(a) Cyclonic depression
(b) Retreating monsoon
(c) Western disturbances
(d) South-west monsoon
Answer:
(c) Western disturbances

4. Monsoon arrives in India as early in:
(a) May
(b) July
(c) June
(d) August
Answer:
(c) June

5. Which one of the following characterises the cold weather season in India?
(a) warm days and warm nights
(b) warm days and cold nights
(c) cold days and cold nights
(d) cold days and warm nights
Answer:
(b) warm days and cold nights

Question 2.
Answer the following questions briefly :
1. What are the controls affecting the climate of India?
Answer:
There are six major controls affecting the climate of India. They are: latitude, altitude, pressure and wind system, distance from the sea, ocean currents and relief features.

2. Why does India have a monsoon type of climate?
Answer:
India has a monsoon type of climate because there is a seasonal reversal in the wind system of India. During 6 months, monsoon winds blow from sea to land, and during the next 6 months, they blow from land to sea. Monsoon winds prevails between 5° and 30° latitudes on both sides of the Equator. India lies in between these latitudes, thus, it is greatly influenced by monsoon winds.

3. Which part of India does experience the highest diurnal range of temperature and why?
Answer:
The Thar desert of Rajasthan in India experiences the highest diurnal range of
temperature. It is because in the Thar desert, the weather conditions drastically change from the day to the night. During the day, there is very high temperature, while during the night, the temperature falls down significantly.

4. Which winds account for rainfall along the Malabar coast?
Answer:
South-west monsoon winds account for rainfall along the Malabar coast.

5. What are Jet streams and how do they affect the climate of India?
Answer:
Jet streams are the narrow belt of high altitude (above 12,000 m) westerly winds in the
troposphere. Their speed varies from about 110 km/h in summer to about 184 km/h in winter.
In India, these jet streams blow from south of the Himalayas, throughout the year, except in summer. The western cyclonic disturbances experienced in the north and north-western parts of the country are brought in by this westerly flow.

6. Define monsoon. What do you understand by “break” in monsoon?
Answer:
Monsoon: The word monsoon is derived from the Arabic word ‘Mausim’, which literally means season. ‘Monsoon’ refers to the seasonal reversal in the wind direction during a year. Break in Monsoon: Rains taking place only for a few days at a time is called “break in monsoon”. In brief, the intermission amid raining is termed as “break’ in monsoon. It is related to the movement of the monsoon.

7. Why is the monsoon considered a unifying bond?
Answer:
India is a vast country. Here variations are found not only in relief, climate and vegetation, but also in life. But the monsoon is a geographical factor that binds these variations of the country together and establishes unity. The arrival of the monsoon brings rains all over the country. Monsoon winds speed up the process of agriculture by providing water to us.

The entire Indian landscape, its wildlife and vegetation life, the entire agricultural program, the lifestyle of the people and their festivals, all revolve around the monsoon. Due to the monsoon, there is a rhythm of the cycle of seasons every years. This is the reason why the monsoon is considered a unifying bond.

Question 3.
Why does the rainfall decrease from the east to the west in Northern India?
Answer:
When the Bay of Bengal branch of south-west monsoon is obstructed by the eastern Himalayas, maximum amount of rainfall is received in West Bengal, Bihar etc. When these winds advance towards west, they go on shedding moisture. Therefore, the amount of rainfall decreases from the east to the west in Northern India.

Question 4.
Give reasons as to why:
1. Seasonal reversal of wind direction takes place over the Indian sub-continent?
Answer:
Reasons for the seasonal reversal of wind direction takes place over the Indian sub-continent are the following:
(a) During winter, there is a high-pressure area over north of the Himalayas. Cold dry winds blow from this region to the low pressure area over the oceans to the south.

(b) In summer, a low-pressure area develops over interior Asia as well as over north-western India. This causes a complete reversal of the direction of winds during summer.

2. The bulk of rainfall in India is concentrated over a few months.
Answer:
In India, most of the rainfall is caused by south-west monsoon which prevails in India only between June to September. Therefore, bulk of rainfall in India is concentrated in these four months only.

3. The Tamil Nadu coast receives winter rainfall.
Answer:
The north-east monsoon winds starts blowing in October month from the land, i.e., north-eastern parts of India to the sea. These bear no water till their access to the Bay of Bengal. However, they get some moisture from the sea here and cause rain in the coast of Tamil Nadu.

4. The delta region of the eastern coast is frequently struck by cyclones.
Answer:
The delta region of the Eastern coast of India is frequently struck by cyclones. This is because the cyclonic depressions that originate over the Andaman Sea are brought in by the sub-tropical easterly jet stream balancing over Peninsular India during the monsoon as well as during the October to November period. The depression moves along East to West direction thus hitting the Eastern coasts.

5. Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought- prone.
Answer:
This happens due to collision of rain bearing Arabian Sea branch of monsoon winds against the highly elevated Western Ghats and depletion of water there. Again, the Aravali hills, being not much elevated, the monsoon winds pass from there without causing rainfall.

Question 5.
Describe the regional variations in the climatic conditions of India with the help of suitable examples.
Answer:
The regional variations in the climatic conditions of India can be understood in the following ways :
1. Temperature:
In summer, the temperature occasionally reaches 50°C in some parts of the Rajasthan’s desert area, whereas it may be around 20°C in Pahalgam in Jammu and Kashmir. On a winter night, temperature at Drass in Jammu and Kashmir may be as low as – 45°C, while Thiruvananthapuram, on the other hand, may have a temperature of 22°G.

2. Rainfall:
Most parts of the country receive rainfall from June to September, but some parts like Tamil Nadu coast get a large portion of rainfall during October and November. The annual precipitation also varies from over 400 cm in Meghalaya to less than 10 cm in Ladakh and Western Rajasthan.

3. Form of precipitation:
While precipitation is mostly in the form of snowfall in the upper parts of Himalayas, it rains over the rest of the country.

4. Direction of winds:
During summer, winds move from sea to land, while during winter, winds move from land to sea.

Question 6.
Discuss the mechanism of monsoon.
Answer:
The monsoons are experienced in the tropical areas roughly between 20°N and 20°S. To understand the mechanism of the monsoon, the following facts are important:

1. The differential heating and cooling of land and water creates low pressure on the landmass of India, while the seas around experience comparatively high pressure.
2. The shift of the position of Inter Tropical Convergence Zone (ITCZ) in summer, over the Ganga plain (this is the equitorial trough normally positioned about 5° N of the equator. It is also known as the monsoon trough during the monsoon season.)
3. The presence of the high-pressure area, east of Madagascar, approximately at 20°S over the Indian Ocean. The intensity and position of this high-pressure area affects the Indian monsoon.
4. The Tibetan plateau get intensely heated during summer, which results in strong vertical air currents and the formation of low pressure over the plateau at about 9 km above sea level.
5. The movement of the westerly jet stream to the north of the Himalayas and the presence of the tropical easterly jet stream over the Indian peninsula during summer.

Question 7.
Give an account of weather conditions and characteristics of the cold season.
Answer:
Weather Conditions of the Cold Season: An account of weather conditions of the cold season is as followin :
1. Time period of the cold season:
The cold weather season begins from mid-November in Northern India and stays till February. December and January are the coldest months in the Northern part of India.

2. Temperature:
The temperature decreases from south to the north. The average temperature of Chennai, on the eastern coast, is between 24°-25°C, while in the northern plains, it ranges between 10°-15°C. Days are warm and nights are cold. Frost is common in the north and the highest slopes of the Himalayas experience snowfall.

3. Winds:
During this season, the north-east trade winds prevail over the country, it is a dry season.

4. Rainfall:
Some amount of rainfall occurs on the Tamil Nadu coast from these winds as here they blow from sea to land.

5. Air pressure:
In the northern part of the country, a feeble high-pressure region develops, with light winds moving outwards from this area.

6. Cyclonic disturbances:
A characteristic feature of the cold weather season over the northern plains is the inflow of cyclonic disturbances from the west and the north-west. These low-pressure systems originate over the Mediterranean Sea and Western Asia and move into India, along with the westerly flow. They cause the much-needed winter rains over the plains and snow fall in the mountains.

7. Characteristics of the Cold Season:
Clear sky, pleasant weather, low temperature and humidity, high range of temperature, cool and slow northern winds are the main characteristics of this season.

Question 8
Give the characteristics and effects of the monsoon rainfall in India.
Answer:
Characteristics of the Monsoon Rainfall: Several characteristic features of the monsoon rainfall are the following :

1. Most of the country gets rainfall from south-west monsoons.
2. The rainfall from the monsoon winds is variable and quite undependable.
3. Much of the rainfall is received in 3-4 months.
4. The distribution of rainfall is highly uneven.
5. Indian rainfall is controlled by orography, i.e., most of the rainfall is caused due to the obstruction of moisture bearing winds.

Effects of the Monsoon Rainfall: The effects of the monsoon rainfall are as hereunder.
1. South-west monsoon does not cause rain regularly. Its amount also varies from year to year.

2. After heavy rainfall, there is decrease in its quantity. Sometimes, long duration of rainy season passes even without rains.

3. Cyclones at the head of the Bay of Bengal control the effectiveness of monsoon winds. From June to September, the number of cyclones is about 8. Intense cyclones give strength to Monsoon winds and helps in causing heavy rainfall, their less intensity causes dry spells.

4. Monsoon trough of low pressure situated over the north plains also affects the distribution of rainfall. The axis of the trough close to the Himalayas causes heavy rains in the mountains and floods in the plains resulting in a great loss to man and material.

5. Success or failure of agricultural crops depends on the amount of rainfall. Thus, Indian agriculture still remains ‘A Gamble to Monsoon’, though, we have tapped irrigation potential to a great extent.

Question 9.
On an outline map of India, show the following:
1. Areas receiving rainfall over 400 cm.
2. Areas receiving less than 20 cm of rainfall.
3. The direction of the south-west monsoon over India.
Answer:

1. Find out which songs, dances, festivals and special food preparations are associated with certain seasons in your region. Do they have some commonality with other regions of India?
Answer:
Students, do it yourself with the help of your teacher.

2. Collect photographs of typical rural houses, and clothing of people from different regions of India. Examine whether they reflect any relationship with the climatic condition and relief of the area.
Answer:
Students, do it yourself with the help of your teacher.

Question 1.
In table-I, the average mean monthly temperatures and amounts of rainfall of 10 representative stations have been given. It is for you to study on your own and convert them into ‘temperature and rainfall’ graphs. A glance at these visual representations will help you to grasp instantly the similarities and differences between them. One such graph (Figure 1) is already prepared for you. See if you can arrive at some broad generalisations about our diverse climatic conditions. We hope you are in for a great joy of learning. Do the following activities.

Answer:
Temperature and Rainfall graph are as shown below:

Question 2.
Re-arrange the 10 stations in two different sequences:
1. According to their distance from the equator.
2. According to their altitude above mean sea-level.
Answer:
1. According to their distance from the equator:

1. Thiruvananthapuram	8°29′ N
2. Bangalore	12°58′ N
3. Chennai	13°4′ N
4. Mumbai	19° N
5. Nagpur	21°9′ N
6. Kolkata	22°34′ N
7. Shillong	24°34′ N
8. Jodhpur	26° 18′ N
9. Delhi	29° N
10. Leh	34° N

2. According to their altitude above mean sea-level:

1. Kolkata	6 m
2. Chennai	7 m
3. Mumbai	11 m
4. Thiruvananthapuram	61 m
5. Delhi	219 m
6. Jodhpur	224 m
7. Nagpur	312 m
8. Bangalore	909 m
9. Shillong	1461 m
10. Leh	3506 m

Question 3.
1. Name two rainiest stations.
2. Name two driest stations.
3. Two stations with most equable climate.
4. Two stations with most extreme climate.
5. Two stations most influenced by the Arabian Sea branch of south-west monsoon.
6. Two stations most influenced by the Bay of Bengal branch of south-west monsoons.
7. Two stations influenced by both branches of the south-west monsoons.
8. Two stations influenced by retreating and north-east monsoons.
9. Two stations receiving winter showers from the western disturbances.
10. The two hottest stations in the months of :
(a) February
(b) April
(c) May
(d) June
Answer:

1. Two rainiest stations:
   (a) Shillong,
   (b) Mumbai.
2. Two driest stations:
   (a) Leh,
   (b) Jodhpur.
3. Two stations with most equable climate:
   (a) Mumbai,
   (b) Thiruvananthapuram
4. Two stations with most extreme climate:
   (a) Leh,
   (b) Jodhpur.
5. Two stations most influenced by the Arabian sea branch of south-west monsoons:
   (a) Mumbai,
   (b) Thirvananthapuram.
6. Two stations most influenced by the Bay of Bengal Branch of south-west monsoons:
   (a) Shillong,
   (b) Kolkata.
7. Two stations influenced by both branches:
   (a) Nagpur,
   (b) Delhi.
8. Two stations influenced by retreating and north-east monsoons:
   (a) Chennai,
   (b) Thiruvananthapuram.
9. Two stations receiving winter showers from the western disturbances:
   (a) Delhi,
   (b) Leh.
10. The two hottest stations in the month of:
    (a) February: Thiruvananthapuram and Chennai.
    (b) April: Nagpur and Chennai.
    (c) May: Nagpur and Delhi/Jodhpur.
    (d) June: Jodhpur and Delhi.

Question 4.
Now find out:
1. Why are Thiruvananthapuram and Shillong rainier in June than in July?
2. Why is July rainier in Mumbai than in Thiruvananthapuram?
3. Why are south-west monsoons less rainy in Chennai?
4. Why is Shillong rainier than Kolkata?
5. Why is Kolkata rainier in July than in June unlike Shillong which is rainier in June than in July?
6. Why does Delhi receive more rain than Jodhpur?
Answer:
1. Thiruvananthapuram is located in Kerala in the southernmost part of India. By early June, monsoon enters India from the south. One of the branches of monsoon winds, i.e., Bay of Bengal branch hits the hills located around Shillong and showers heavy rainfall. As Thiruvananthapuram and Shillong come first in the way of monsoon winds, they are more rainier in June than in July.

2. In the month of July, the monsoon winds pass from Thiruvananthapuram and enter the interior parts of India, thus, July is less rainier in this city. On the other hand, in Mumbai, the monsoon winds rising from Arabian Sea continuously cause rainfall due to the presence of Western Ghats.

3. The Bay of Bengal branch of south-west monsoons causes heavy rains in the western parts of Western Ghats. Chennai lies in the extremely east. When the monsoon winds reach over there, they become almost dry. Chennai lies in rain-shadow area of south-west monsoon.

4. Shillong is situated on hills which trap the monsoon winds and force them to cause rainfall. But Kolkata is situated in plains where monsoon winds reach comparatively late and there are no such hills which could trap the monsoon winds.

5. South-west monsoon first strikes Shillong and then Kolkata. Thus, Shillong receives more rainfall in June itself and as these winds move on to Kolkata, they start causing rainfall over there in July.

6. Delhi creates barrier in the path of south-west (Bay of Bengal branch) monsoon while Jodhpur does not create any resistance in the path of south-west (Arbian Sea Branch) monsoon.

Question 5.
Now think why:
1. Thiruvananthapuram has equable climate?
2. Chennai has more rains only after the fury of monsoon is over in most parts of the country?
3. Jodhpur has a hot desert type of climate?
4. Leh has moderate precipitation almost throughout the year?
5. While in Delhi and Jodhpur most of the rain is confined to nearly three months, in Thiruvananthapuram and Shillong it is almost nine months of the year? In spite of these facts see carefully if there are strong evidences to conclude that the monsoons still provide a very strong framework lending overall climatic unity to the whole country.
Answer:
1. Thiruvananthapuram has an equable climate because it is closer to the sea and its climate is moderated by the sea. Being close to the Equator, it is also influenced by the equatorial type of climate where the annual range of temperature happens to be the least.

2. Over the most parts of India, rainfall occurs due to south-west monsoon winds. These winds start retreating in September to October months. At this time, north-east trade winds blow all over India. These winds receive vapour while moving over the Bay of Bengal which immediately carry to the Coromandel coast in Tamil Nadu. Thus, Chennai receives heavy rain during winter season.

3. Jodhpur falls in the rain shadow area and it is situated near to the Thar desert. This station has, therefore, extreme climate. There is also scarce of vegetation. Thus, it has a hot desert type of climate.

4. Leh is situated on the high altitude in Ladakh. Thus, we can see here the precipitation in the form of snow. The lowest temperature also freezes the water. Therefore, Leh has moderate precipitation almost throughout the year.

5. Delhi and Jodhpur are located in the interior parts of country where monsoon winds reach comparatively late. On the other hand, Thiruvananthapuram and Shillong are located on the sea coast where monsoon winds strike first and cause heavy rainfall.

JAC Class 9 Social Science Solutions

JAC Board Class 9th Social Science Important Questions History Chapter 5 Pastoralists in the Modern World

I. Objective Type Questions

1. Who are the pastoral nomadic communities of Jammu and Kashmir?
(a) Raikas
(b) Gaddhi shepherds
(c) Gujjar Backarwals
(d) Bhotiyas.
Answer:
(c) Gujjar Backarwals

2. The Dhangar shepherds stayed in the central plateau of Maharasthra during the :
(a) monsoon
(b) winter
(c) autumn
(d) summer.
Answer:
(a) monsoon

3. When did the colonial government in India passed the Criminal Tribes Act?
(a) 1871
(b) In 1879
(c) In 1840
(d) In 1947
Answer:
(a) 1871

4. Where do the Massai cattle herders reside?
(a) West Africa
(b) East Africa
(c) South Africa
(d) North America
Answer:
(b) East Africa

5. Where is Samburu National Park located?
(a) Uganda
(b) Tanganyika
(c) Kenya
(d) None of the above.
Answer:
(c) Kenya

II. Very Short Answer Type Questions

Question 1.
Who are nomadic pastoralists?
Answer:
Nomadic pastoralists are people who move from one place to another with their herds to earn a living.

Question 2.
What is a pasture?
Answer:
It is grass or other plants grown for feeding or grazing animals, as well as land used for grazing.

Question 3.
Write the most significant feature of nomadic pastoralists.
Answer:
The most significant feature of nomadic pastoralists is their cycle of seasonal movement.

Question 4.
List some pastoral communities of the Himalayas.
Answer:
Gujjar Bakarwals, Gaddi shepherds, Bhotiyas, Sherpas and Kinnauris.

Question 5.
Where did the Gujjar herders stay in winters and summers?
Answer:
The Gujjar herders, in winters, came down to the dry forests of the Bhabar, and in summers, they went up to the high meadows i.e., the Bugyals.

Question 6.
What is Bhabar?
Answer:
Bhabar is a dry forested area below the foothills of Garhwal and Kumaun.

Question 7.
Who are Bugyals?
Answer:
Bugyals are the vast meadows in the high mountains.

Question 8.
In which state Dhangars are found?
Answer:
Dhangars are an important pastoral community of Maharashtra.

Question 9.
Why are the Konkani peasants welcome by Dhangar shepherds?
Answer:

1. Dhangar flocks manure the fields.
2. The animals feed on the stubble of the Kharif crop.

JAC Class 9 Social Science Important Questions

Jharkhand Board JAC Class 10 Science Solutions Chapter 6 Life Processes Textbook Exercise Questions and Answers.

JAC Board Class 10 Science Solutions Chapter 6 Life Processes

Jharkhand Board Class 10 Science Life Processes Textbook Questions and Answers

Question 1.
The kidneys in human beings are a part of the system of ……………….
A. nutrition
B. respiration
C. excretion
D. transportation
Answer:
excretion

Question 2.
The xylem in plants are responsible for ……………….
A. transport of water
B. transport of food
C. transport of amino acids
D. transport of oxygen Answer: transport of water

Question 3.
The autotrophic mode of nutrition requires ……………….
A. carbon dioxide and water
B. chlorophyll
C. sunlight
D. all of the given
Answer:
all of the given

Question 4.
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in ……………….
A. cytoplasm
B. mitochondria
C. chloroplast
D. nucleus
Answer:
mitochondria

Question 5.
How are fats digested in our bodies? Where does this process take place?
Answer:
Large fat globules break into small fine droplets by the effect of bile salts of bile juice. This is called emulsification of fats.

Pancreatic lipase acts on emulsified fats to break it and finally intestinal lipase digests fats into fatty acids and glycerol. This process take place in small intestine.

Question 6.
What is the role of saliva in the digestion of food?
Answer:
Saliva contains salivary amylase (ptyalin) which digests starch into sugar.

Question 7.
What are the necessary conditions for autotrophic nutrition and what are its by-products?
Answer:
The necessary conditions for autotrophic nutrition are:

• Presence of chlorophyll
• Absorption light energy
• Splitting of water molecules
• Reduction of carbon dioxide to carbohydrates.

Oxygen is the by-product.

Question 8.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Answer:

Aerobic respiration	Anaerobic respiration
1. O2 is used in this process.	1. O2 is not used in this process.
2. At the end of this process CO2 and H2O are produced.	2. At the end of this process in medium of plant origin Ethanol and CO2 are produced and in medium of animal origin only lactic acid is produced and no CO2.
3. In aerobic respiration complete oxidation of glucose molecules occurs, in which one mole of glucose on oxidation releases much greater energy.	3. In anaerobic respiration glucose molecules are incompletely oxidized, so one mole of glucose releases less energy along with the organic by products.
4. There are two phases in aerobic respiration, the first phase occurs in the cytoplasm and does not utilize O2. The second phase occurs in the mitochondria and utilizes O2.	4. There is only one phase in anaerobic respiration. It occurs in the cytoplasm. It occurs entirely in the absence of O2.

Question 9.
How are the alveoli designed to maximise the exchange of gases?
Answer:
The alveoli are located at the terminal ends of bronchioles. They are balloon-like structures provides large surface area for exchange of gases with an extensive network of blood vessels.

Question 10.
What would be the consequences of a deficiency of haemoglobin in our bodies?
Answer:
A deficiency of haemoglobin in our bodies leads to a disease called anaemia. Due to this, cells of our body do not get sufficient oxygen for cellular respiration, which may lead to release less energy. Weakness, fatigue, tiredness, etc. conditions may arise.

Question 11.
Describe double circulation of blood in human beings. Why is it necessary?
Answer:
Blood passes through the heart twice during each cycle in human beings. This is called double circulation.

[Deoxygenated blood from different organs is drained and finally through vena cava it is poured in right atrium. Prom here this blood is transported to lungs via right ventricle. In lungs, blood become oxygenated and is again transported to left atrium. From here it transports in left ventricle and then by aorta to different body parts.]

It is necessary because it allows a highly efficient supply of oxygen to the body cells, which fulfill the high energy need of body.

Question 12.
What are the differences between the transport of materials in xylem and phloem?
Answer:

In xylem	In phloem
1. Water and minerals are transported.	1. Food especially carbohydrate, sucrose is translocated.
2. Transpiration pull becomes the major driving force for transport in xylem.	2. Osmotic pressure is responsible for translocation in phloem.
3. Generally ATP is not used for transport of material in xylem.	3. Phloem tissue uses ATP for translocation of food materials.
4. Vessels and tracheids are involved in transport.	4. Sieve tube and companion cells are involved in translocation.

Question 13.
Compare the functioning of alveoli in the lungs to their structure and functioning.
Answer:

Alveoli	Nephrons
1. It is a structural and functional unit of lung.	1. It is a structural and functional unit of kidney.
2. Alveoli are balloon-like structures at the terminal region of bronchioles.	2. Nephrons are long-coiled tube-like structures having Bowman’s capsule at the tip.
3. The alveoli provide a surface for exchange of gases.	3. Filtration of blood for removing of nitrogenous wastes take place in nephron units.
4. The wall of the alveoli contain an extensive network of blood vessels.	4. A cluster of blood capillaries associated with Bowman’s capsule called glomerulus and tubular part of nephron is surrounded by network of blood capillaries.

Jharkhand Board Class 10 Science Life Processes InText Questions and Answers

Question 1.
Why is diffusion insufficient to meet the oxygen requirement of multicellular organisms like humans?
Answer:
In multicellular organisms like human, all the cells are not in direct contact with the s surrounding environment. The body structure is more complex and the body size is also large. Therefore, simple diffusion will not be sufficient to s send oxygen to every cell. It has been estimated that a period of 3 years would be needed to carry a molecule of O₂ from our lungs to reach our toes through diffusion.

So, diffusion is insufficient to meet the oxygen requirement of multicellular organisms like humans.

Question 2.
What criteria do we use to decide whether something is alive?
Answer:
Movement, growth, breathing, cell-structure, etc. are the criteria we use to decide whether something is alive.

Question 3.
What are outside raw materials used for by an organisms?
Answer:

Name of outside raw materials	Used for
1. CO2, H2O	Photosynthesis by plants
2. Carbon based food source, O2	Respiration by aerobic organisms

Question 4.
What processes would you consider essential for maintaining life?
Answer:
The processes essential for maintaining life are nutrition, respiration, transport, excretion, etc.

Question 5.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
Answer:

Autotrophic Nutrition	Heterotrophic Nutrition
1. It occurs in green plants and some bacteria.	1. It occurs in animals and fungi.
2. In such mode of nutrition. food is synthesised from inorganic components, i.e., CO2 and H2O.	2. In such mode of nutrition food is consumed from other organisms.
3. Photosynthesis is important process for autotrophic nutrition.	3. Food digestion is important for such nutrition.

Question 6.
Where do plants get each of the raw materials required for photosynthesis?
Answer:
Raw materials required for photosynthesis :

• CO₂ : Plants get it from atmosphere.
• H₂O : Plants root absorbed it from soil.
• Energy : Plants get it directly from sun.

Question 7.
What is the role of the acid in our stomach?
OR
What are the functions of the acid in our stomach?
Answer:
Role or Functions of the acid:

• Acid destroys the bacteria and other microorganisms that enter the stomach, along with the food.
• It converts the inactive enzyme pepsinogen into active enzyme pepsin.
• It provides acidic medium required for the action of pepsin. Pepsin can digest proteins present in food only in acidic medium.
• Insoluble mineral salts get dissolved in acid.

Question 8.
What is the function of digestive enzymes?
Answer:
Digestive enzymes hydrolyse / digest complex component (carbohydrates, lipids, proteins) of food into simple, soluble and absorbable form of nutrients.

Question 9.
How is the small intestine designed to absorb digested food?
Answer:
Small intestine is long tubular structure. The inner lining of the small intestine has numerous finger like projection called villi, which increase the surface area for absorption.

Question 10.
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Answer:
The amount of dissolved oxygen is fairly low in aquatic environment as compared to the amount of oxygen in the air. So, terrestrial organisms fulfil their oxygen demand with low breathing rate as compared to aquatic organisms.

Question 11.
What are the different ways in which glucose is oxidised to provide energy in various organisms?
Answer:
There are three different ways in which glucose is oxidised to provide energy in various organisms.

Question 12.
How is oxygen and carbon dioxide transported in human beings?
Answer:
In human beings, the respiratory pigment haemoglobin has high affinity for oxygen, so it is mostly transported by haemoglobin. Carbon dioxide is more soluble in water than oxygen and hence it is mostly transported in dissolved form in our blood.

Question 13.
How are the lungs designed in human beings to maximise the area for exchange of gases?
Answer:
The respiratory passage in the lungs, divides into smaller and smaller tubes which finally terminate in balloon – like structures alveoli. The alveoli present in lungs provide the maximum area for exchange of gases in human beings.

Question 14.
What are the components of the transport system in human beings? What are the functions of these components?
Answer:

The components of the transport system in human	Functions
1. Blood Plasma Red blood corpuscles White blood corpuscles Platelets	Acts as fluid transport medium of various material. Transport of food, CO2, salts and nitrogenous wastes. Transport of O2. Fight with invading pathogens. Help in clotting mechanism during injury.
2. Heart	It acts as a blood pumping organ.
3. Blood vessels Arteries Veins Capillaries	Carry blood away from the heart. Carry blood from different organs and bring it back to the heart. Exchange of material between the blood and surrounding cells.
4. Lymph	Carries digested and absorbed fat from intestine and drain excess fluid from intercellular spaces back into the blood.

Question 15.
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer:
It is necessary to separate oxygenated s and deoxygenated blood in mammals and birds because it allows a highly efficient supply of oxygen to the body and this is useful in their high energy needs for to maintain constant body temperature.

Question 16.
What are the components of the i transport system in highly organised plants?
Answer:
Xylem tissue (vessels and tracheids) and phloem tissue (sieve tube and companion cell) are the components of the transport system in highly organised plants.

Question 17.
How are water and minerals transported in plants?
Answer:
Water conducting channels : Xylem consists of vessels and tracheids, which form continuous water conducting channel.

Absorption of water by the roots : The root cells actively take up ions from soil. This creates a difference in the concentration of these ions between the root and the soil. Water, therefore moves into the root from the soil to eliminate this difference.

Column of water : To eliminate the concentration difference between the soil and the root, the steady movement of water into root creates column of water.

Conduction of water by root pressure : Due to absorption of water by root cells, a pressure is generated to push water in xylem element.

This pressure is insufficient to move water over the heights of plants. So, plants use another strategy to move water in xylem upwards to the highest points of the plant body.

Conduction of water by transpiration pull : The loss of water in the form of vapour from the aerial parts of the plant is known as transpiration.

The water which is lost through the stomata is replaced by water from the xylem vessels in the leaf. Evaporation of water molecules from the cells of a leaf creates a sunction which pulls water from the xylem cells of roots.

During the day when the stomata are open, the transpiration pull becomes the major driving force in the movement of water in the xylem.

At night effect of root pressure is necessary for the upward flow of water.

Thus, transpiration helps in absorption and upward movement of water and minerals dissolved in it from roots to the leaves.

Question 18.
How is food transported in plants?
Answer:
The transport of soluble products of photosynthesis is called translocation.

• Translocation occurs in the part of the vascular tissue known as phloem.
• Besides, the products of photosynthesis, the phloem transports amino acids and other substances. These substances are especially delivered to roots, fruits, seeds and to growing organs where it is stored.
• The translocation of food and other substances takes place in the sieve tubes with the help of adjacent companion cells both in upward and downward directions.
• The translocation in phloem is achieved by utilising energy.
• Sucrose (Sugar / Carbohydrate) is transferred into phloem tissue using energy from ATP. This increases the osmotic pressure of the tissue causing water to move into it.
• This pressure moves the material in the phloem to tissues having less pressure. The phloem thus moves material according to the plant’s need.

Example: In the spring, sugar stored in root or stem tissue is transported to the buds which need energy to grow.

Question 19.
Describe the structure and functioning of nephrons.
Answer:
Nephron is a basic filtration unit in the kidneys.

• Each kidney has large numbers of nephrons packed closely together.
• Nephron is a long-coiled tubular structure which begins with a cup-shaped end. called Bowman’s capsule and it ends in collecting tubule.
• A cluster of very thin-walled blood capillaries seen in the Bowman’s capsule is called glomerulus.
  

The purpose of making urine is to filter out waste products from blood.

• Nitrogenous wastes such as urea, uric acid, etc. are removed from blood in the kidneys.
• Urine is produced by filtration units i.e., nephrons.
• Cup-shaped Bowman’s capsule collects the filtrate.
• Some substances in the initial filtrate, such as glucose, amino acids, salts and a major amount of water are selectively reabsorbed as the urine flows along the coiled tube.
• The amount of water reabsorbed depends on the amount of water present in the body and amount of dissolved waste which is to be excreted.
• Thus, urine is formed in both kidneys. [In a normal healthy adult, the initial filtrate in the kidneys is about 180 L daily. However, the s volume of excreted urine is only a litre or two per day. The remaining filtrate is reabsorbed ; in the kidney tubules.]

Question 20.
What are the methods used by plants to get rid of excretory products?
Answer:
Unlike animals, the plants do not possess any special organs or system for excretion. However, the plants excrete their wastes in different ways:

• O₂ produced during photosynthesis by the green plants is set free directly in the atmosphere.
• Plants remove surplus water by the process of transpiration through the stomata.
• Sometimes plants store certain wastes in the cells of their leaves which are ultimately shed off.
• Certain plants store wastes in the cellular vacuoles of their cells.
• Other waste products such as resin and gum are stored especially in old xylem.
• Plants excrete some waste substances into the soil around them.

Question 21.
How is the amount of urine produced regulated?
Answer:
The amount of urine formed depends on how much excess water there is in the body, and on how much of dissolved waste there is to be excreted. More water and dissolved wastes in the body will produce more urine. On the other hand, less water and less dissolved wastes will produced less urine.

Activity 6.1 [T. B. Pg. 96]

To demonstrate that chlorophyll is essential for photosynthesis.

Materials : Potted plant (money plant or croton), beaker, water bath, alcohol, iodine.

Procedure :

• Take a potted plant of money plant or croton with variegated leaves.
• Keep the potted plant in complete darkness for three days.
• After three days expose the plant to bright sunlight for about 6 hours.
• Pluck one such leaf of this plant which is green in certain parts and white in the other remaining parts.
• Mark the green areas in it and trace them on a papersheet.
• Boil this plucked leaf in a beaker full of alcohol and kept in boiling water bath for some time, till it becomes colourless.
• Wash and clean this colourless leaf with water and dip it, for a few minutes, in dil. iodine solution.
• Observe the colour of the leaf and compare this with tracing of the leaf done in the beginning.
  

Questions:

Question 1.
What happens when the plant is kept in s a dark for 2-3 days?
Answer:
All the starch gets used up when the plant is kept in a dark for 2-3 days.

Question 2.
What happens to the colour of the leaf when keep in boiling alcohol?
Answer:
When the leaf is kept in boiling alcohol, it gets decolourised.

Question 3.
What is the colour of the alcohol solution when leaf is taken out from it?
Answer:
The colour of the alcohol solution is green when leaf is taken out from it.

Question 4.
State the use of iodine solution.
Answer:
Iodine solution is used to know the presence of starch.

Question 5.
What can you conclude about the presence of starch in various areas of the leaf?
Answer:
We conclude that the presence of starch is detected with iodine solution in only such areas where chlorophyll present.

Question 6.
What will you infer from this activity?
Answer:
This activity explains that chlorophyll is essential for photosynthesis and surplus glucose stored in form of starch as internal reserve energy.

Activity 6.2 [T. B. Pg. 97]

To demonstrate that carbon dioxide (CO₂) necessary for photosynthesis

Materials : Potted plants, Bell-jar, watch glass, KOH (potassium hydroxide), alcohol, iodine solution.

Procedure:

• Take two potted plants. Place them in dark for three days. This will de-starch them.
• After three days place each of the pots on a smooth glass plate.
• Label one pot as A and the other as B.
• Keep a small watch glass or petri dish containing pellets of potassium hydroxide (KOH) on the glass plate near the pot A.
• Cover both the potted plants under two separate glass bell-jars.
• Apply a thick coat of vaseline on the bottom of the bell-jar close to the glass plate in order to make both the jars air-tight.
• Expose both these plants to sunlight for about 2 to 3 hours.
• Thereafter pluck one leaf each from the plants A and B and examine these leaves separately for the presence of starch therein.
  

Questions :

Question 1.
Which gas is absorbed by KOH from the air in the bell-jar?
Answer:
Carbon dioxide is absorbed by KOH from the air in the bell-jar.

Question 2.
Which potted plant (A or B) shows the presence of starch in its leaf?
Answer:
B potted plant shows the presence of starch in its leaf.

Question 3.
Why is starch not formed in the leaf of the plant kept under the bell-jar with KOH kept along with it?
Answer:
Starch is not formed in the leaf of the plant kept under the bell-jar with KOH kept along with it because KOH absorbs COa from air. So, CO₂ is not available for the photosynthesis and thus starch is not formed.

Question 4.
Write your inference based on your observation and study.
Answer:
The potted plant B showed normal photosynthesis in presence of CO₂. This shows that CO₂ is necessary for photosynthesis.

Question 5.
In order to prevent the increase of which gas in the atmosphere, the conservation of plant organisms (trees) are important?
Answer:
To prevent the increase of CO₂ gas in the atmosphere, the conservation of plant organisms (trees) are important.

Question 6.
Do both the leaves show the presence of same amount of starch?
Answer:
No.

Activity 6.3 [T. B. Pg. 99]

To check the effect of saliva on starch. Materials : Two test tubes, starch solution, iodine.

Procedure:

• Take 1 mL starch solution in two test tubes (A and B).
• Add 1 mL saliva to test tube A and leave both test tubes undisturbed for 20 – 30 minutes.
• Now add a few drops of dilute iodine solution to the test tubes.
  

Questions:

Question 1.
In which test tube do you observe a colour change?
Answer:
In test tube B colour change is observed.

Question 2.
What does this indicate about the presence or absence of starch in the two test tubes?
Answer:
Test tube B solution showed colour change means there is presence of starch. While in test tube A colour is not changed that means starch is absent.

Question 3.
What is the difference in colour of solution, A and B after adding iodine solution?
Answer:
Colour of solution A is yellow and colour of solution B is blue or black after adding iodine solution.

Question 4.
The colour of solution in tube A does not change to blue or black. Why?
Answer:
The colour of solution in test tube A does not change blue or black because starch is hydrolysed by the effect of enzymes present in saliva.

Question 5.
Which component of food is digested (partially) when the food is chewed in the mouth?
Answer:
Starch (Carbohydrate) is partially digested when the food is chewed in the mouth.

Question 6.
Why does the bread or chapati tastes sweet when chewed for a longer time?
Answer:
When bread or chapati chewed for a longer time, starch is converted to simple sugar by salivary amylase. The sugar formed produces sweet taste in mouth.

Question 7.
State which of the following edible substances in our food are the source of starch: Potato, Lettuce leaf. Wheat, Maize, Sweet pea. Groundnut, Ghee.
Answer
Potato, Wheat, Maize, etc. are the sources of starch in our food.

Activity 6.4 [T. B. Pg. 101]

To demonstrate that CO₂ is exhaled by us during breathing.

Materials : Two test tubes, Rubber tube, Pichkari, Lime water.

Procedure :

• Take two clean glass test tubes. Label one of the tubes as (a) and the other as (b).
• In each test tube add about 10 mL of freshly prepared lime water (Ca(OH)₂ solution).
• Use a syringe or pichkari to pass air through some fresh lime water taken in test tube (a).
• Blow air through tube in a lime water taken in test tube (b).
• Note how long it takes for this lime water to turn milk in each test tube.
  

Questions :

Question 1.
What change is observed in test tube (a) and test tube (b)? Why?
Answer:
Lime water turns milky in test tube (a) and test tube (b). Because of presence of CO₂ the colour of lime water is changed.

Question 2.
In which tube does the change occur more rapidly? Why?
Answer:
In test tube (b), the change occurs more rapidly because the air that we expell contain more CO₂.

Question 3.
What does this activity tell us about the amount of carbon dioxide in the air that we breathe out?
Answer:
This activity tells us that the amount of carbon dioxide is more in the air that we breathe out.

Question 4.
What you conclude from this activity?
Answer:
Carbon dioxide is produced in the process of respiration.

Activity 6.5 [T. B. Pg. 101]

To demonstrate that CO₂ is produced during fermentation.

Materials : Test tube. Bent glass tube, Fruit juice, Yeast powder. Lime water. One holed cork.

Procedure :

• Take some fruit juice or sugar solution and add some yeast to this mixture.
• Take this mixture in a test tube fitted with one holed cork.
• Fit the cork with a bent glass tube.
• Dip the free end of the glass tube into a test tube containing freshly prepared lime water.
  

Questions :

Question 1.
What change is observed in the colour of Ca(OH)₂ solution?
Answer:
The colour of Ca(OH)₂ solution turns milky.

Question 2.
How much time does it take for the change of colour?
Answer:
It takes long time for the change of colour of lime water.

Question 3.
Which product of fermentation is responsible for bringing about the change in colour of lime water?
Answer:
CO₂ is a product of fermentation is responsible for bringing about the change in colour of lime water.

Question 4.
What does this activity tell us about the products of fermentation?
Answer:
This activity tells us about the products of fermentation which are CO₂ and ethanol.

Activity 6.6 [T. B. Pg. 103]

To compare the breathing rate of fish and human.

Materials : An aquarium

Procedure:

• Observe moving fish in an aquarium.
• Count the number of times the fish opens and closes its mouth in a minute.
• Count the number of times you breathe in and out in a minute.
• Compare the breathing count of fish with yours.

Questions :

Question 1.
What is an operculum?
Answer:
An operculum is folded covering of gill slits in some fishes.

Question 2.
By which organ do fish respire?
Answer:
Fish respires with gills.

Question 3.
Are the timing of the opening and closing of the mouth and gill-slits in fish coordinated in some manner?
Answer:
Yes, in fish when mouth opens, gill-slits close and vice versa.

Question 4.
How do fish respire?
Answer:
Fishes take in water through their mouths and force it over the gills where the dissolved oxygen is taken up by blood capillaries by diffusion and CO₂ is released in water. Such water is discarded through gill slits.

Question 5.
What is an average breathing rate per minute in experimental fish?
Answer:
An average breathing rate 66-78 per minute in experimental fish.

Question 6.
What is an average breathing rate per minute in human beings?
Answer:
An average breathing rate 12-16 per minute in human beings.

Question 7.
Why in aquatic animal the breathing rate is much faster than that seen in terrestrial animals?
Answer:
Since the amount of dissolved oxygen is fairly low in water as compared to the amount of oxygen in the air, the rate of breathing in aquatic animal like fish is much faster than that seen in terrestrial animals.

Activity 6.7 [T. B. Pg. 105]

To know the haemoglobin content in human beings and in animals like buffalo, cow, etc.

• Visit a health centre in your locality and find out the normal range of haemoglobin content in human beings.
• Visit a veterinary in your locality. Find out the normal range of haemoglobin content in an animal like buffalo, cow, etc.
• Compare the difference seen in male and female human beings and animals.

Questions :

Question 1.
What is the normal range of haemoglobin content in human beings?
Answer:
The normal range of haemoglobin content 12-18 g/ decilitre.

Question 2.
Is it the same for children and adult?
Answer:
No, in children (3 month to 12 years) haemoglobin content 11.0 ± 1.5 g / decilitre.

Question 3.
Is there any difference in the haemoglobin levels for men and women?
Answer:
Yes, Men ⇒ 13-18 g / decilitre
Women ⇒ 12-16 g / dl

Question 4.
Is the haemoglobin content different in calves, male and female animals?
Answer:
Yes.

Question 5.
What is the normal range of haemoglobin content in cow and buffalo?
Answer:
Cow-10 to 15 g /decilitre
Buffalo -12.5 to 14.5 g / decilitre

Activity 6.8 [T. B. Pg. 109]

To demonstrate the physiological process of transpiration in plant.

Materials : A pot with growing plant, a pot with similar size with same amount of soil. a stick, plastic sheet.

Procedure:

• Take two small pots of approximately the same size and having the same amount of soil.
• One pot labelled as (a) with a plant.
• Place a stick of the same height in other pot labelled as (b).
• Cover the soil in both pots with a plastic sheet.
• Cover both pots, with plastic sheets and place them in bright sunlight for half an hour.

Questions :

Question 1.
Why the soil in both pots is covered with a plastic sheet?
Answer:
The soil in both pots is covered with a plastic sheet to prevent evaporation and loss of moisture.

Question 2.
What do you observe after half an hour?
Answer:
After half an hour, small water droplets are observed on the inner surface of a plastic sheet of pot (a).

Question 3.
What do you conclude from your observation?
Answer:
From our observation, we concluded that there is a water loss from aerial part of a plant in the form of vapour. This process is called transpiration.

JAC Board Class 9th Social Science Important Questions Geography Chapter 5 Natural Vegetation and Wildlife

I. Objective Type Questions

1. Which of the following terms is being used to denote the species pf animals of a particular region or period?
(a) Fauna
(b) Animals
(c) Flora
(d) All of these.
Answer:
(a) Fauna

2. Which type of forests are restricted to heavy rainfall areas of the Western Ghats and the island groups of Lakshadweep and Andaman-Nicobar?
(a) Mangrove forests
(b) Tropical deciduous forests
(c) Tropical evergreen forests
(d) all of these.
Answer:
(c) Tropical evergreen forests

3. Which type of forest is also known as monsoon forests?
(a) Mangrove forests
(b) Tropical deciduous forests
(c) Tropical evergreen forests
(d) None of these.
Answer:
(b) Tropical deciduous forests

4. Red panda is a rare animal found in:
(a) Montane forests
(b) Tropical evergreen forests
(c) Mangrove forests
(d) all of these.
Answer:
(a) Montane forests

5. How many biosphere reserves have been set up by the government of India?
(a) Ten
(b) Twelve
(c) Five
(d) Fourteen.
Answer:
(d) Fourteen.

II. Very Short Answer Type Questions

Question 1.
What are the three forms of natural vegetation?
Answer:

1. Forests,
2. Grasses,
3. Bushes.

Question 2.
How many countries of the world having mega bio-diversity?
Answer:
12 countries.

Question 3.
What place does India hold in the world in plant diversity?
Answer:
Tenth.

Question 4.
What place does India hold in Asia in plant diversity?
Fourth.

Question 5.
Distinguish between indigenous species and exotic species.
Answer:
The natural vegetation, which are purely Indian, are known as endemic or indigenous species, but those which have come from outside India are termed as exotic plants.

Question 6.
How does land affect the natural vegetation?
Answer:
Land affects the natural vegetation directly and indirectly. The fertile plain level is generally devoted to agriculture. The undulating and rough terrains are areas where grassland and woodlands develop and give shelter to a variety of wild life.

Question 7.
What affects the variation in duration of sunlight?
Answer:
The variation in duration of sunlight at different places is due to differences in latitude, altitude, season and duration of the day. Due to longer duration of sunlight, trees grow faster in summer.

Question 8.
How does precipitation affect the vegetation?
Answer:
In India, almost the entire rainfall is received by the advancing south-west monsoon (June to September) and retreating north-east monsoons. Areas of heavy rainfall have denser vegetation as compared to other areas of less rainfall.

Question 9.
Which type of forests found in areas having more than 200 cm of rainfall?
Answer:
Tropical evergreen forests.

Question 10.
Name the commercially important trees of tropical evergreen forests.
Ebony, Mahogany, Rosewood, Rubber and Cinchona.

Question 11.
Which are the most widespread forests of India?
OR
Which forests are also called monsoon forests?
Answer:
Tropical deciduous forests.

Question 12.
How are the tropical deciduous forests divided on the basis of availability of water?
Answer:

1. Moist deciduous forests,
2. Dry deciduous forests.

Question 13.
Write any two finding areas of moist deciduous forests.

1. Jharkhand,
2. West Odisha.

Question 14.
Which are the important trees of dry deciduous forests?
Answer:
Teak, Sal, Peepal and Neem.

Question 15.
Name the common animals of tropical deciduous forests.
Answer:
Lion, tiger, pig, deer, elephant, lizard, snake and tortoise.

Question 16.
In what amount of rainfall the thorn forests are found?
Answer:
Less than 70 cm of rainfall.

Question 17.
In which areas of India, the scrubs are found?
Answer:
In the north-western part of the country including semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana.

Question 18.
What are the main plant species of the thorny forests?
Answer:
Acacias, palms, euphorbias and cacti.

Question 19.
State any two characteristics of the thorny trees and scrubs.

1. The stems are succulent to conserve water,
2. Leaves are mostly thick and small to minimize evaporation.

Question 20.
What type of trees are found between the height of 1500 metres and 3000 metres?
Answer:
Coniferous trees.

Question 21.
Give any four examples of coniferous trees.
Answer:
Pine, deodar, silver fir and spruce.

Question 22.
Name the common animals found in the montane forests.
Answer:
The common animals found in these forests are-Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear and rare red panda, sheep and goats with thick hair.

Question 23.
By which nomadic tribes, the Alpine grasslands are used?
Answer:
The Gujjars and the Bakarwals.

Question 24.
Where does the mangrove vegetation found in India?
Answer:
Mangrove forests are found in the deltas of the Ganga, the Mahanadi, the Krishna, the Godavari and the Kaveri.

Question 25.
Name the most famous tree of mangrove forests.
Answer:
Sundari trees.

Question 26.
Name the famous animal of mangrove forests.
Answer:
Royal Bengal Tiger.

Question 27.
In which state is Gir forest located?
Answer:
Gir forest is located in Gujarat state of India.

Question 28.
How many plants have been described in Ayurveda?
Answer:
About 2000 plants.

Question 29.
How many medicinal plants have named by the World Conservation Union’s Red List?
Answer:
The World Conservation Union’s Red List has named 352 medicinal plants, of which 52 are critically threatened and 49 are endangered.

Question 30.
Which medicinal plant is used to treat blood pressure?
Answer:
Sarpagandha.

Question 31.
Where are the one-horned rhinoceros found in India?
Answer:
In swampy and marshy lands of Assam and West Bengal.

Question 32.
In which place of India wild asses are found?
Answer:
Arid areas of Rann of Kachchh.

Question 33.
Name the only country in the world that has both tigers and lion.
Answer:
India.

Question 34.
When was the Wildlife Protection Act of India implemented?
Answer:
In 1972.

Question 35.
Name any four biosphere reserves in India where wildlife is protected.
Answer:

1. Nilgiri,
2. Nanda Devi,
3. Gulf of Mannar,
4. Sunderban.

Question 36.
In which season, the Siberian crane comes in India?
Answer:
During the winter season.

Question 37.
Name any two National parks.
Answer:

1. Ranthambore National Park,
2. Kanha National Park.

Question 38.
Write the names of any two wildlife sanctuaries.
Answer:

1. Sariska and
2. Chandra Prabha.

Question 39.
How do the human beings influence the ecology of a region?
Answer:
Human beings utilise the vegetation and wildlife. The greed of man leads to exploitation of these resources. They insensibly cut the trees and kill the animals, creating ecological imbalance. As a result, some of the plants and animals have reached the verge of extinction.

Question 40.
Write any three developmental projects introduced by government to protect the endangered species of India.

1. Project Tiger,
2. Project Rhino,
3. Project Great Indian Bustard.

Question 41.
How many national parks and wildlife sanctuaries have been set up to conserve our natural heritage?
Answer:
104 National Parks and 543 Wildlife Sanctuaries.

III. Short Answer Type Questions

Question 1.
Write a notes on bio-diversity in India.
Answer:
India is rich in biodiversity. It is one of the twelve mega bio-diverse countries of the world. It has 47,000 species of plants including 15000 flowering plants. India also has many species of non-flowering plants. Besides its floral diversity, India also has about 90,000 species of animals. India also has rich variety of fishes in its fresh and marine water.

Question 2.
How does the land have an impact on flora and fauna?
Answer:
Land affects the natural vegetation directly and indirectly. The nature of the land i.e., plain, hilly or a plateau, determines the kind of vegetation which will grow in it. Fertile lands are used for growing crops, vegetables and fruits.
Undulating and rough surfaces generally develop either into grasslands and woodlands (forests) and give shelter to a variety of wildlife.

Question 3.
How does the soil have an impact on flora and fauna? Explain with examples.
Answer:
The soils also vary from place to place. Different types of soils provide different types of vegetation. For example, deltaic or alluvial soil at a river delta near the sea will sustain mangrove forests, while slopes of hills have conical trees. The sandy soils of the desert support cactus and thorny bushes.

Question 4.
How does the temperature have an impact on flora and fauna?
Answer:
The character and extent of vegetation are mainly determined by temperature along- with humidity in the air. As the climate gets colder, either by increase in altitude (above 915 metres) or by moving away from the equator, the vegetation will change from tropical to sub-tropical, temperate and then alpine. For example, on the slope of the Himalayas and hills of the Peninsula, the fall in temperature affects the type of vegetation and its growth.

Question 5.
Explain the uses of forests.
Answer:
The uses of forests are as follows:

1. Forests are renewable resources and play a major role in enhancing the quality of environment.
2. They modify the local climate, control soil erosion, regulate stream flow and support a variety of industries.
3. They provide livelihood for many communities and offer panoramic and scenic view for recreation.
4. They control the force of winds and temperature and cause rainfall.
5. They provide humus to the soil and natural habitat to the wildlife.

Question 6.
Distinguish between moist deciduous and dry deciduous forests.
Answer:
Differences between moist deciduous and dry deciduous forests are as follows:

Moist deciduous forests	Dry deciduous forests
1. These types of forests are found in areas with annual rainfall of 100 to 200 cm.	1. This types of forests are found in areas with annual rainfall of 70 to 100 cm.
2. Teak, bamboo, sal, shisham, sandalwood, khair, kusum, aijun and mulberry trees are prominent in these forests.	2. Teak, sal, neem and peepal trees are prominent in these forests.
3. These forests have not been cleared much.	3. Large areas of these forests have been cleared to cultivative and grazing.

Question 7.
What are the differences between thorn forests and mangrove forests?
Answer:
Differences between thorn forests and mangrove forests are as follows:

Thom forests	Mangrove forests
1. These types of forests are found in areas with annual rainfall less than 70 cm.	1. These types of forests are found in the delta regions of rivers and are not depen¬dent on amount of rainfall.
2. These types of forests are mainly found in most of Rajasthan, Gujarat and in some areas of Uttar Pradesh, Haryana.	2. These types of forests are mainly found in the coastal delta regions.
3. Babool, kikar, palm, cactus, acacia trees and bushes are found here.	3. Sundari, palm, coconut, keora and agar trees are found here.

Question 8.
Why is it necessary to conserve our natural resources of forests and wildlife?
Answer:
The natural resources are a common heritage which we have inherited from our forefathers, and in turn, we will pass them over to our future generations. Conservation does not mean that we should not use the natural resources, but it means that we should use them wisely. All the plants and animals in a given area are so closely interlinked and interdependent, that they cannot survive without each other.

The large-scale poaching (killing) of wild animals, residing in the forests by man is a serious threat to the survival of many animal and bird species. This also disturbs the food chains in which these animals occur, resulting in undesirable consequences for the whole ecosystem. Thus to avoid these consequences, special efforts of their conservation are required.

Question 9.
What are the major objectives to set up the Biosphere Reserves in India?
Answer:
9 Biosphere Reserves have been set up in India to protect flora and fauna. The major objectives of these Biosphere Reserves are:

1. To conserve and maintain diversity and integrity of the natural heritage in its full form, i.e., physical environment, the flora and the fauna.
2. To provide facilities for education, awareness and training. The major goal of setting up such reserves is to preserve the genetic diversity in crucial natural ecosystems.

Question 10.
What are the names of bio-reserves regions in India?
Answer:
The following are the bio-reserves regions in India: Sundarbans, Simplipal, Gulf of Mannar, Dihang-Dibang, Nilgiri, Dibru-Saikhoula, Nanda Devi, Agasthyamalai, Nokrek, Kangchen- dzonga, Great Nicobar, Pachmarhi, Manas, Achanakmar- ‘ Amarkantak, Kachchh, Cold Desert, Seshachalam Hill, Panna.

III. Long Answer Type Questions

Question 1.
The distribution of flora and fauna is mainly determined by the climate in India. Justify this statement by giving relevant facts.
Answer:
This is true that the distribution of flora and fauna is mainly determined by the climate. Climatic factors like temperature, photoperiod and precipitation highly affect the climate of a region in India. The given points state how climatic factors affect climate and determines distribution of flora and fauna.
1. Temperature:
The character and extent of vegetation and distribution of fauna is mainly determined by temperature alongwith humidity in the air, precipitation and soil. On the slopes of the Himalayan mountains and the hills of the peninsula above the height of 915 m, the fall in the temperature affects the types of vegetation, its growth, and changes it from tropical to sub-tropical, temperate and alpine vegetation. Along with this, they affect the distribution of wildlife too.

2. Photoperiod (Sunlight):
The variation in duration of sunlight at different places is due to differences in altitude, latitudes, season and duration of the day.
Due to longer duration of sunlight, trees grow faster in summers.

3. Precipitation:
In India, almost the entire rainfall is brought in by the advancing south-west monsoon (June to September) and retreating north-east monsoon. Area of heavy rainfall have more dense vegetation and fauna as compared to other areas of less rainfall.

Question 2.
Explain the important characteristics of tropical evergreen forests.
Answer:
The main characteristics of tropical evergreen or tropical rain forests are:

1. These forests are found in areas with an annual rainfall of about 200 cm.
2. These forests grow in the areas of high temperature and high rainfall.
3. In these forests, trees grow very vigorously, reaching height of 60 m and above.
4. These forests yield hardwood trees.
5. There is no definite time for trees to shed their leaves. As such, these forests appear green all the year round.
6. Rainy parts of Western Ghats, Assam, West Bengal, island groups of the Lakshadweep and the Andaman and Nicobar Islands and Odisha have these type of forests.
7. Ebony, mahogany, rosewood, rubber, cinchona and shisham are some of the commercially-important trees.

Question 3.
Explain the important features of the thorn forests.
Answer:
The important features of the thorn forests are:

1. The areas having rainfall less then 70 cm support this type of vegetation.
2. Due to lack of moisture, the trees growing here have very small leaves and they bear thorns.
3. The common species found here include babool, kikar and palm in the areas of moderate rainfall. In areas of more scanty rainfall, they consist of scrubs, shrubs and thorny bushes.
4. The main features of thorny forests are that the trees are scattered and have long plant roots penetrating deep into the soil and spreading in a radial pattern to get water. Leaves are mostly thick and small to minimize loss of water,
5. Rajasthan, Gujarat, parts of Punjab, Haryana and dry parts of Madhya Pradesh and the Deccan plateau alongwith the rain-shadow area have this type of vegetation.

Question 4.
Describe the principal features of the montane forests.
Answer:
The principal features of the montane forests are as follows:

1. In mountainous areas, the decrease in temperature with increasing altitude leads to the corresponding change in the natural vegetation. As such there is a succession of natural vegetation belts in the same order as we see from the tropical to the tundra region.
2. The wet temperate type of forests are found between a height of 1,000 and 2,000 metres. Evergreen broad-leaf trees such as oaks and chestnuts predominate.
3. Between, 1,500 and 3,000 metres, temperate forests containing coniferous trees like pine, deodar, silver fir, spruce and cedar, are found. These forests cover mostly the southern slope of the Himalayas and places having high altitude in southern and north-east India.
4. At high altitudes, generally more than 3,600 metres above sea level, temperate forests and grasslands give way to Alpine vegetation. Silver fir, junipers, pines and birches are the common trees of these forests.
5. They get progressively stunted as they approach the snow-line. Ultimately, through shrubs and scrubs, they merge into the Alpine grasslands. At higher altitudes, mosses and lichens form part of the tundra vegetation.
6. The common animals found in these forests are the Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear and rare red panda, sheep and goats with thick hair.

Question 5.
Write the important characteristics of mangrove forests.
Answer:
The important characteristics of mangrove forests are:

1. These forests occur in and around the deltas, estuaries and creeks prone to tidal influences and as such are also known as deltaic or tidal forest.
2. White littoral forests occur at several places along the coast. Swamp forests are
   confined to the deltas of the Ganga, the Mahanadi, the Godavari, the Krishna and the Kaveri. ‘
3. The most peculiar feature of these forests is that they can survive and grow both in fresh as well as salt water.
4. In the Ganga-Brahmaputra delta, the most important tree is the Sundari tree, after which Sunderban has been named. Palm, coconut, keora and agar also grow in some parts of the delta.
5. Royal Bengal Tiger is the prominent animal in these forests. Turtles, crocodiles, gharials and snakes are also found in these forests.

Question 6.
Write a note on the commonly-used plants in India.
Answer:
India is known for its herbs and spices from ancient times. Some 2,000 plants have been described in Ayurveda. The commonly-used plants in India are :

1. Sarpagandha: It is found only in India and is used to treat blood pressure.
2. Jamun: The juice from its ripe fruit is used to prepare vinegar which is carminative and diuretic and has digestive properties. The powder of the seeds is used for controlling diabetes.
3. Aijun: The fresh juice of leaves is a cure for earache. It is also used to regulate blood pressure.
4. Babool: Leaves are used as a cure for eye sores. Its gum is used as a tonic.
5. Neem: It has high antibiotic and anti-bacterial properties.
6. Tulsi: It is used to cure cough and cold.
7. Kachnar: It is used to cure asthma and ulcers. The buds and roots are good for curing digestive problems.

Question 7.
Write a detailed note on wildlife in India.
Answer:
India has a varied fauna due to great diversity of the relief and climate. There are approximately 90,000 different species of fauna. The fresh water and marine species of fish amount to 2,546. It constitutes 12 per cent of the world’s total fish stock. India is a home to about 2,000 mammals species of birds, which account for around 13 per cent of the world’s total species of birds. India has about 5 to 8 per cent of the world’s amphibians, reptiles and mammals.

The elephants are the most magestic animals among the mammals. As they prefer hot wet forests, so they are found in the dense rainy forests of Assam in the north-east and in Kerala and Karnataka in the south. Camels are found mainly in hot and arid Thar Desert of Rajasthan. Wild asses dominate the arid areas of Rann of Kachchh One-homed rhinoceros also fall in the category of mammals.

They live in swampy and marshy land of Assam and West Bengal. The other animals included in the category of mammals are the Indian bison, Indian buffalo, nilgai (blue bull), chausingha (four-homed antelope), black buck, gazel and deer.

1. Animals of prey:
Among the animals of prey, Indian lion and tiger are remarkable. Lion’s natural habitat is confined to the Gir forests of Saurashtra in Gujarat. The famous Bengal tiger has its natural habitat in the Sunderban in the tidal forests occupying the edge of the Ganga delta. The other animals belonging to cat family are leopards, clouded leopards and snow leopards.

2. Animals of the Himalayan Regions:
Snow leopards, sheep, mountain goats, the ibex, the shrew bear and the red panda are the important animals of the Himalayas. Ladakh’s freezing high altitudes are home to yak, the shaggy horned wild ox, the Tibetan antelope, the bharal (blue sheep), wild sheep and the kiang (Tibetan wild ass). .

3. Monkeys:
Indian forests are homes of several species of monkeys. The most famous is the langur.

4. Birds:
India has a rich variety of beautiful and colourful birds. They include pheasants, geese, ducks, mynahs, parakeets, pigeons, cranes, hombills and sun birds. Most bird species inhabit forests, but some have their natural habitats in swamps and wet lands.

5. Water animals:
In the rivers, lakes and coastal areas, turtles, crocodiles and gharials are found.

Question 8.
What steps have been taken by the government of India to protect the flora and fauna of the country ?
Answer:
Flora and fauna are essential for the survival of human beings and to maintain the ecological balance. Due to excessive exploitation of the plants and animal resources by human beings some of them are on the verge of extinction and some have already become extinct.

To stop the indiscriminate destruction of flora and fauna, the following steps have been taken by the government of India :
1. Eighteen biosphere reserves have been establish in the country to protect flora and fauna. Four out of these, the Sundarbans in the West Bengal, Nanda Devi in Uttarakhand, the Gulf of Mannar in Tamil Nadu, the Nilgiris (Kerala, Karnataka and Tamil Nadu) have been included in the World Network of Biosphere Reserves.

2. Financial and technical assistance is provided to various botanical gardens by the government since 1992.

3. 104 National Parks, 543 Wildlife Sanctuaries and Zoological Gardens have been established to take care of this natural heritage.

Question 1.
For identification only:
Vegetation Type: Tropical Evergreen Forests, Tropical Deciduous Forests, Thorn Forests, Montane Forests and Mangrove Forests.
Answer:

Question 2.
For Locating and Labelling:
1. National Parks: Corbett, Kaziranga, Ranthambore, Shivpuri, Kanha, Simlipal and Manas.
2. Wildlife Sanctuaries: Sariska, Mudumalai, Rajaji, Dachigam.
3. National Parks: Tadoba, Sanjay Gandhi, Keloadeo, Rajgir, Bendipur, Guindy.
Answer:

JAC Class 9 Social Science Important Questions

Jharkhand Board JAC Class 10 Maths Solutions Chapter 10 Circles Ex 10.1 Textbook Exercise Questions and Answers.

JAC Board Class 10 Maths Solutions Chapter 10 Circles Exercise 10.1

Question 1.
How many tangents can a circle have?
Solution :
A circle can have infinite number of tangents.

Question 2.
Fill in the blanks:
(i) A tangent to a circle intersects it in ________ point (s).
(ii) A line intersecting a circle in two points is called a _______.
(iii) A circle can have _________ parallel tangents at the most.
(iv) The common point of a tangent to a circle and the circle is called ________.
Solution :
(i) one,
(ii) sccant,
(iii) two,
(iv) point of contact.

Question 3.
A tangent PQ at a point P of a circle of radius 5 cm meets a line through the centre O at a point Q so that OQ = 12 cm. Length PQ is:

(A) 12 cm
(B) 13 cm
(C) 8.5 cm
(D) \(\sqrt{119}\) cm.
Solution :
PQ² = OQ² – OP² (Using Pythagoras theorem)
= (12)² – (5)²
= 144 – 25
= 119.
PQ = \(\sqrt{119}\) cm.

Question 4.
Draw a circle and two lines parallel to a given line such that one is a tangent and the other, a secant to the circle.
Solution :
AB is the given line. CD is the secant and PQ is the tangent to the circle at point R.

Jharkhand Board JAC Class 10 Science Important Questions Chapter 6 Life Processes Important Questions and Answers.

JAC Board Class 10 Science Important Questions Chapter 6 Life Processes

Additional Questions and Answers

Question 1.
Distinguish between :
(1) Gastric juice and Bile
Answer:

Gastric juice	Bile
1. It is a mixture of secretions from gastric glands located in the inner wall of the stomach.	1. It is secreted from the liver cells.
2. It is not stored anywhere in stomach.	2. It is stored in the sac-called gall bladder.
3. It is secreted from the gastric glands in stomach and acts in the stomach itself.	3. It is secreted from the liver cells and acts in the duodenum (small intestine).
4. It is an acidic digestive juice.	4. It is an alkaline digestive juice.
5. It contains dil. HCl, enzyme pepsin and mucus.	5. It does not contain any enzyme.

(2) Herbivores animals and Carnivores animals
Answer:

Herbivores animals	Carnivores animals
1. These animals take in only plant material as food.	1. These animals take in only animal flesh and bones as well as blood as their food.
2. Their small intestine is relatively much longer than in carnivores.	2. Their small intestine is relatively much shorter than in herbivores.
3. They are consumers of the first order.	3. They are consumers of the second and third order.
4. The digestion of cellulose of the plant cells is quite complex and takes time.	4. The digestion of flesh of the animals is quite easy and rapid.
5. Example: rabbit, cow, buffalo, goat, etc.	5. Example: tiger, lion, leopard, wolf, etc.

(3) Respiration in plants and Respiration in animals
Answer:

Respiration in plants	Respiration in animals
1. In plants, exchange of gases is carried out individually by different organs (roots, stem and leaves in the process of respiration.)	1. In animals, exchange of gases is carried out by some definite parts or organs of the body, meant for respiration.
2. The flow of respiratory gases from one part of the body to the other, is a slow process.	2. The flow of respiratory gases from one part of the body to the other, is a rapid process.
3. The respiration in plants is slow.	3. The respiration in animals is quite rapid.
4. In anaerobic respiration in plants the end product is ethanol and CO2.	4. In anaerobic respiration in animals the end product is lactic acid.

(4) Xylem tissue and Phloem tissue
Answer:

Xylem tissue	Phloem tissue
1. It transports water and mineral Ions absorbed by the roots to different parts of the plant.	1. It transports organic products of photosynthesis from the leaves to different parts of the plant.
2. The principal conducting elements of xylem are tracheids and tracheae (vessels).	2. The principal conducting elements of phloem are sieve cells and sieve tubes with companion cells.
3. The conduction occurs only in upward direction.	3. The conduction occurs in both upward and downward directions.
4. It conducts only water and mineral ions.	4. Along with the sugars it conducts amino acids, plant hormones and several other substances.
5. For conduction of water In the xylem, the suction force due to transpiration is the principal force.	5. For conduction of organic food substances the energy required is obtained from ATP.

(5) Conduction of water in plants and Translocation of food in plants
Answer:

Conduction of water in plants	Translocation of food in plants
1. It occurs through the xylem tissue.	1. It occurs through the phloem tissue.
2. It occurs from the roots to the stem, leaves and flowers.	2. It occurs from the leaves to different parts of the plant.
3. It occurs only from below upwards.	3. It occurs from above downwards as well from below upwards.
4. A continuous water column is formed in the plant from root upwards which is pulled up due to suction force.	4. No food column is formed but the difference of pressure causes translocation which requires energy from ATP.

(6) Atria and Ventricles
Answer:

Atria	Ventricles
1. The upper two chambers of the heart are atria.	1. The lower two chambers of the heart are ventricles.
2. They are relatively thin-walled.	2. They are quite thick-walled.
3. Atria receive blood from different parts of the body and is poured in the ventricles.	3. Ventricles receive blood from the auricles and force the blood towards different parts of the body.
4. In atrium, the blood pressure is relatively low.	4. In ventricles, the blood pressure is quite high.

(7) Artery and Vein
Answer:

Artery	Vein
1. The blood vessel that carries blood from the heart to different organs is called an artery.	1. The blood vessel that carries blood from any organ towards the heart is called a vein.
2. In artery, the blood flows under higher pressure.	2. In vein, the blood flows under somewhat low pressure.
3. The wall of the artery is relatively thick and elastic.	3. The wall of the vein is relatively thin and less elastic.
4. The artery divides into several arterioles and numerous fine blood capillaries in the organs and tissues.	4. In the organs and tissues, the veins are formed by the union of numerous blood capillaries and several venules.
5. Arteries carry oxygenated blood (exception -Pulmonary artery).	5. Veins carry deoxygenated blood (exception -Pulmonary vein).

(8) Blood and Lymph
Answer:

Blood	Lymph
1. It is red coloured fluid connective tissue.	1. It is a colourless liquid connective tissue.
2. It contains liquid blood plasma and freely floating blood corpuscles.	2. It contains a certain amount of blood plasma, proteins and some blood cells (except red blood corpuscles).
3. It flows in the heart, arteries, veins and blood capillaries.	3. It flows in the intercellular spaces, larger lymph capillaries and in lymph ducts.
4. It is an independent liquid connective tissue.	4. It arises by the diffusion from the thin walls of the blood capillaries and after circulation in the body, it is poured back in the blood.

(9) Breathing and Respiration
Answer:

Breathing	Respiration
1. It is a physical / mechanical process.	1. It is a physiological process.
2. It occurs through the respiratory organs aided by accessory respiratory organs.	2. It occurs in each and every living cell of the body.
3. The mechanism of breathing is not necessarily found in all the living organisms.	3. The process of respiration occurs invariably in each and every living cell of all the living organisms.
4. It includes the physical processes of inhalation or inspiration expelled (taking in of atmospheric air) and exhalation or expiration (throwing out air contaihing CO2, into the atmosphere).	4. It includes the physiological (biochemical) processes of glycolysis and Krebs cycle and also oxidative phosphorylation.
5. There are no subtypes of breathing.	5. Aerobic and anaerobic respiration are the two different types of respiration.
6. Energy is utilized in this process.	6. Energy is released in this process.

Question 2.
Give scientific reasons for the following statements:
(1) Proper transportation (conducting) system is necessary in higher plants.
Answer:
The green leaves of plants obtain CO₂ from the atmosphere and synthesize carbohydrates. The plants, through their roots, absorb water and other raw mineral elements essential for the constitution of the body, from the soil.

In higher plants the distance between the roots and the leaves being more, the water, mineral elements and the products of photosynthesis cannot be sent to all the different parts of the plant body, merely by diffusion from cell to cell. Therefore, in order to distribute all these substances rapidly and timely, a proper transportation (conducting) system is necessary in higher plants.

(2) In very tall plants, the suction force created due to transpiration is the main conducting force for water and mineral ions through the xylem.
Answer:
The xylem tissue in all the organs of a plant remains connected to each other and forms a continuous path for the flow of water, etc. Thus, a continuous water column is formed therein.

Mere root pressure, created in small herbs, is not sufficient to push water and minerals to the great height of very tall plants. The plants adopt another way to reach the target of fulfilling the water requirement. Evaporation of water molecules in the form of vapour occurs through stomata.

Due to that a suction force arises in the cells of leaves. This suction force comes into being from the cells of the leaves and is gradually experienced in the xylem of roots. As a result, the water column in the xylem rises up. Hence in very tall plants, the suction force created due to transpiration is the main conducting force for water and mineral ions through the xylem.

(3) Translocation in the phloem takes place in both upward and downward directions.
Answer:
The phloem transports amino acids, various plant hormones and other organic substances in addition to the products of photosynthesis.

Carbohydrates are synthesized in the leaves due to photosynthesis. These carbohydrates are transported to the roots and stem through phloem. The plant hormones synthesized in shoot apex flow downwards through the phloem and the plant hormones synthesized in the root apex and the food reserve stored in roots are transported upwards through the phloem. Thus, the translocation in the phloem takes place in both, upward and downward directions.

(4) The right side chambers of the heart have deoxygenated blood and left side chambers have oxygenated blood in them.
Answer:
The four-chambered heart, in man, is formed of two atria and two ventricles. All the four chambers of the heart are separated from each other by septa.

Deoxygenated blood from different organs of the body (except lungs) is brought through s superior and inferior vena cava and poured in the right atrium and then into the right ventricle, Similarly oxygenated blood from the two lungs is brought through pulmonary veins and poured in the left atrium and then into the left ventricle.

The four-chambered heart prevents the mixing of oxygenated blood with deoxygenated blood. Hence, the right side chambers of the heart have deoxygenated blood and the left side chambers have oxygenated blood in them.

(5) Lymph separates from the blood and remixes with the blood.
Answer:
The lymph oozes out through the pores in thin walls of the blood capillaries, as a fluid from the blood flowing through the capillaries. It flows very slowly in the intercellular spaces between the tissue cells. The intercellular spaces have no walls of their own and are called lymph capillaries.

These lymph capillaries meet and join with each other to form larger ones which finally open in a vein to pour its contents. Thus, lymph, as a colourless watery fluid collects in a large lymph vessels that finally open in particular veins S in the body to pour its contents back in blood.

(6) The wall of the artery is thick and elastic while that of vein is relatively thin.
Answer:
The arteries carry blood from the heart towards different organs. When the ventricles contract, the blood is pushed in the arteries under high pressure. In order to withstand this pressure, the arteries must have thick and elastic walls. The veins receive blood from different organs and carry it to the heart. The blood in the veins flows at relatively low pressure. Hence, the wall of the veins is relatively thin and less elastic.

(7) The organisms possessing chlorophyll are autotrophs.
Answer:
The organisms, possessing chlorophyll, can trap and utilize the solar energy to synthesize their own food using CO₂ and water. This process of trapping the solar energy for synthesis of ones own food is called photosynthesis and the mode of nutrition of such organisms is called autotrophic. In photosynthesis, the food synthesized is the simplest hexose sugar-glucose, which is utilized for obtaining energy. The surplus glucose is stored as reserve food in the form of starch. Hence, the organisms possessing chlorophyll are autotrophs.

(8) The stomata in leaves keep on opening and closing.
Answer:
On one or both the surfaces of the leaves of flowering plants, there are numerous stomata as minute pores. Each of these pores is guarded by a pair of guard cells. The opening and closing of the stomata is controlled by these guard cells, which contain chloroplasts.

When water enters the guard cells, the latter swell and cause the opening of stomata and when the guard cells lose water, the guard cells contract and cause the closing of stomata. Thus, the stomata in leaves keep on opening and closing due to entry and exit of water in the guard cells.

(9) The parasitic mode of nutrition is harmful for the host organism.
Answer:
In parasitic nutrition, one organism depends fully for obtaining its nutritional needs, directly on other living organism. The latter is called a host from whom the parasite directly obtains food. The parasitic organism keeps close contact with the host and sucks or absorbs nutrients from its body. The host goes on becoming weaker physically and physiological. The health of host thus is affected. Thus, the parasitic mode of nutrition is harmful for the host organism.

(10) HCl (Hydrochloric acid) is an important constituent of gastric juice.
Answer:
For the chemical digestion of food in stomach, the stomach secretes gastric juice from its gastric glands. HCl is one of the constituents of gastric juice.

HCl destroys the bacteria and other micro¬organisms entering along with the ingested food and thereby prevent the decay of food in stomach. HCl provides acidic medium for the action of gastric enzyme. HCl converts inactive enzyme pepsinogen into an active enzyme pepsin. Pepsin acts in acidic medium on proteins and starts their digestion and convert them into preoteoses and peptones. Thus, HCl is an important constituent of gastric juice.

(11) The length of small intestine of herbivorous is relatively much longer than that of carnivorous.
Answer:
The length of small intestine is different in different animals and that depends upon the nature of food taken by the animal. The carnivorous eat flesh. The digestion of flesh as food is quite easy and rapid and there is very small amount of roughage.

Hence these animals have short small intestine. The herbivorous eat grass and other vegetation. The cellulose of the plant cells is a complex substance and its complete digestion needs more space and time and hence longer small intestine and longer large intestine. Hence, the length of small intestine of herbivorous is relatively much longer than that of carnivorous.

(12) Bile is an important digestive juice though it does not contain any digestive enzymes.
Answer:
Bile is a greenish yellow alkaline digestive juice secreted from the liver cells. Bile contains bile salts, certain bile pigments but does not contain any digestive enzymes.

The bile salts turn the acidic food from stomach, alkaline and thereby provide alkaline medium for further reactions in intestine. Pancreatic enzymes and intestinal enzymes need alkaline medium. Bile salts emulsify the large fat globules into a very large number of very minute fat droplets and thereby greatly increase the exposed surface area of fat for the rapid action of lipases. Hence bile is an important digestive juice though it does not contain any digestive enzymes.

(13) Respiration is important to keep the organism in living state.
Answer:
The living cells of the body need energy for performing various vital functions. The energy is obtained by the biological oxidation of organic nutrients in the cell.

The process of breakdown of food sources for cellular needs either using oxygen or without oxygen is called respiration. The energy, so released is for continuation of various functions and thereby ‘ maintaining the living state of the organism. Thus, respiration is essential for life.

Question 3.
Carefully observe the given diagram and answer the questions related with it:

Questions :

1. Identify label x and state any two process that occur through it.
2. Identify label y and state the name of process and equation that occurs in it.
3. Identify label z and which situation you think for the given diagram?
4. What you think about transportation during day from label x in given diagram?

Answer:

1. x – stomatal pore, exchange of gases and transpiration occur through it.
2. y – chloroplast, photosynthesis process occurs in it.
   
3. z – guard cells, the guard cells swell when water flows into them, causing the stomatal pore to open.
4. During the day when stomata are open, the transpiration pull becomes the major driving force in the movement of water in xylem.

Questions :

1. Identify x and state the name of enzyme secreted in it and a medium required for its action.
2. Which juice is secreted from y? Where does it show its action and state the name of process which occurs by it?
3. State the name of specific finger-likc projections located in z and its functions.
4. Which other finger-like projection do you know and where can you observe it?

Answer:

1. x – stomach, name of enzyme is pepsin and acidic medium is required for its action.
   Bile juice secreted from y. It shows its action in small intestine and emulsification (breakdown of fat globules) process occurred by it.
2. Specific finger-like projections in the walls of z are villi. It increases surface area for absorption of food.
3. We know other finger-like projections are pseudopodia. We can observe it on the cell surface of amoeba.

Questions :

1. Which type of blood circulation you see in this diagram, what it means?
2. Which type of blood flows through x? Which one is exceptional for this?
3. Which type of blood flows through y? Why?
4. How our body gets highly efficient supply of oxygen?

Answer:

1. Double circulation. It means blood goes through the heart twice during each cycle.
2. Oxygenated blood flows through x. Pulmonary artery is exceptional because it transports deoxygenated blood.
3. Oxygenated blood flows through y. Because it carries blood from lungs to heart and in lungs blood becomes oxygenated.
4. The separation of the right side and the left side of the heart is useful to keep oxygenated and deoxygenated blood from mixing.

Questions:

1. Which structure is shown in the above diagram? Which nitrogenous wastes is removed from blood by this structure?
2. Identify x and mention its shape and function.
3. Identify y and z.
4. Compare the blood flowing through u and v blood vessles.

Answer:

1. Structure of nephron shown in the diagram. Nitrogenous wastes such as urea and uric acid are removed from blood by it.
2. x – Bowman’s capsule. It is cup-shaped and collects the filtrate.
3. y – collecting duct, z – glomerulus.
4. u – It transports oxygenated blood containing more nitrogenous wastes, v – It transports deoxygenated blood with lesser nitrogenous wastes due to filtration.

Objective Questions and Answers

Question 1.
Answer the following questions in short:
(1) Which inorganic substances are used as raw materials by autotrophic organisms?
Answer:
Water and CO₂ are the inorganic substances used as raw material for the synthesis s of organic food by autotrophic organisms.

(2) What is the mode of nutrition in fungi?
Answer:
The fungi show heterotrophic nutrition, in which breakdown the food material outside the body and then absorb it.

(3) Name one organism each, having saprophytic, parasitic and holozoic modes of nutrition.
Answer:

Mode of nutrition	Name of organism
Saprophytic	Most of fungi
Parasitic	Tapeworm, Ascaris
Holozoic	Amoeba, Human

(4 ) In addition to carbon dioxide and water, state two other conditions necessary for the process of photosynthesis.
Answer:
Presence of chlorophyll in the cells and <: the presence of sunlight are also necessary, in addition to CO₂ and water, for photosynthesis.

(5) Why there is a controversy about whether viruses are truly alive or not?
Answer:
There is a controversy about whether viruses are truly alive or not, because viruses do not show any molecular movement in them unless they infect specific host cell.

(6) Why are molecular movements needed for life?
Answer:
Molecular movements are needed for life because all the structures of living cells are made up of molecules and they must move molecules around all the time.

(7) On what the survival of heterotrophs depend? Give example of heterotrophic organisms?
Answer:
The survival of heterotrophs depends directly or indirectly on autotrophs.
Example of heterotrophic organisms : Animals and fungi.

(8) Which form of carbohydrate is stored in green plants and in human beings?
Answer:
Carbohydrates in the form of starch is stored in green plants while in human beings it is stored as glycogen.

(9) How desert plants perform process of photosynthesis?
Answer:
Desert plants take up carbon dioxide at night and prepare an intermediate which is acted upon by the energy absorbed by the chlorophyll during the day.

(10) Where does the exchange of gases occur in plants other than stomatal pores?
Answer:
The exchange of gases occurs across the surface of stems, roots and leaves other than in stomatal pores of plants.

(11) What is the function of guard cells?
Answer:
The opening and closing of the stomatal pore is a function of the guard cells.

(12) What is the essentiality of nitrogen element?
Answer:
Nitrogen is an essential element in the synthesis of protein and other compounds.

(13) Give the name of organisms that use parasitic nutritive strategy.
Answer:
The name of organisms that use parasitic nutritive strategy are cuscuta, ticks, lice, leech, tapeworm, etc.

(14) How a food vacuole is formed in amoeba?
Answer:
Amoeba takes in food using temporary finger-like extensions called pseudopodia of the cell surface which fuse over the food particle forming a food vacuole.

(15) What is peristaltic movement?
Answer:
The rhythmic movement shown by the contractions of the muscles of lining of alimentary canal which push the food only in one direction is called peristaltic movement.

(16) What causes acidity in adults?
Answer:
Acidity is caused due to excess secretion of hydrochloric acid in stomach.

(17) State the name of enzyme involved in digestion of protein and its location.
Answer:

Name of enzyme involved in digestion of protein	Location
(1) Pepsin	Gastric juice
(2) Trypsin	Pancreatic juice

(18) In which type of respiration more energy is released?
Answer:
In aerobic respiration more energy is released.

(19) Which part of root is involved in the exchange of respiratory gases?
Answer:
The root hairs, formed from the epidermal cells of the root, are involved in the exchange of respiratory gases.

(20) Name the respiratory organ of fish.
Answer:
The fish possesses pharyngeal gills as respiratory organs.

(21) In which pathway of breakdown of glucose CO₂ is not produced?
Answer:
Anaerobic respiration in our muscle cells

(22) Why the air passage does not collapse in our body?
Answer:
Rings of cartilage are present in the trachea so that the air passage does not collapse in our body.

(23) What are the characteristics of respiratory surface?
Answer:
Respiratory surface is very fine, delicate, moist and contains an extensive network of blood vessels and it remains in contact with atmosphere.

(24) Why the lungs always contain a residual volume of air?
Answer:
Thle lungs always contain a residual volume of air so that there is sufficient time for oxygen to be absorbed and for carbon dioxide to be released.

(25) Give the name, location and function of respiratory pigment in human beings.
Answer:
In human beings, respiratory pigment

(26) What is called single circulation?
Answer:
Blood goes only once through the heart in the fish body during the once circulation.

(27) What is the function of blood capillaries?
Answer:
Exchange of material between blood and the surrounding cells takes place across the thin wall of blood capillaries.

(28) What is the significance of lymph?
Answer:
Lymph carries digested and absorbed fat from small intestine and drains excess fluid from intercellular space back into the blood.

(29) Who forms conducting tubes in higher plants? What are transported through it?
Answer:
Xylem and phloem forms conducting tubes in higher plants. Xylem transports water and minerals, phloem transports products of photosynthesis.

(30) How sunction is created in xylem? What is it significance?
Answer:
Evaporation of water molecules from the cells of a leaf creates a sunction in xylem. It pulls water from the xylem cells.

(31) State any two points of importance of transpiration in plants?
Answer:
Importance of transpiration in plants:

• It helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.
• It helps in temperature regulation.

(32) State the name of forces important for the movement of water in the xylem during day and at night respectively?
Answer:
Transpiration pull during day and root pressure at night are important forces for the movement of water in the xylem.

(33) Which substances are transported through phloem?
Answer:
Sucrose, amino acids and other substances are transported through phloem.

(34) Which component of phloem shows translocation of food? In which direction does s it take place?
Answer:
The translocation of food takes place in the sieve tubes with the help of adjacent companion cells of phloem and in both upward and downward directions.

(35) Explain translocation of sugar in the spring season in plants.
Answer:
In the spring season, sugar stored in root or stem tissue is translocated to the buds which need energy to grow.

(36) Which substances are selectively reabsorbed from initial filtrate in the tubular part of nephron?
Answer:
Glucose, amino acids, salts and a major amount of water are selectively reabsorbed from initial filtrate in the tubular part of nephron.

(37) Until when urine is stored in the urinary bladder?
Answer:
Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra.

(38) Why we can usually control the urge to urinate?
Answer:
We can usually control the urge to urinate because the bladder can store urine and it is under voluntary nervous control.

(39) State name and location of any three structures which are richly supplied with blood vessels.
Answer:

Structure	Location
(1) Villi	Wall of intestine
(2) Alveoli	Terminale of bronchioles in lungs
(3) Nephron	In the kidneys

Question 2.
Define : OR Explain the terms :
(1) Nutrition
Answer:
A process of transfer of a source of energy from outside the body of the organism to the inside is called nutrition.

(2) Photosynthesis
Answer:
A process of synthesis of simple form of carbohydrate, i.e. glucose with the use of solar energy, water and carbon dioxide in presence of chlorophyll is called photosynthesis.

(3) Autotrophs
Answer:
Those organisms which utilise simple inorganic sources in the form of carbon dioxide and water and synthesise complex food are called autotrophs.

(4) Heterotrophs
Answer:
Those organism which utilise complex food material prepared by other organisms are called heterotrophs.

(5) Digestion
Answer:
A process by which complex food components are transformed into simple, soluble and absorbable form with the help of enzymes is called digestion.

(6) Respiration
Answer:
A process of breakdown of food source such as glucose, in presence or in absence of oxygen inside the living cell to provide energy for cellular need is called respiration.

(7) Breathing
Answer:
A process of inhalation and exhalation is called breathing.

(8) Transpiration
Answer:
A process of loss of water in the form of vapour from the aerial parts of the plant is known as transpiration.

(9) Excretion
Answer:
The biological process involved in removal of nitrogenous metabolic wastes from the body is called excretion.

Question 3.
Fill in the blanks :

1. The substance, used in cellular respiration, is ………………..
2. The effect of ……………….. in transport of water is more important at night.
3. Carbohydrate is synthesized by the reduction of COa in the process of ………………..
4. The secretions from the liver and pancreas are poured in the ………………..
5. Human beings show ……………….. mode of nutrition.
6. The enzyme ……………….. digests starch and converts it into maltose.
7. Pepsin is an enzyme that can act only in ……………….. medium.
8. The digestion of food particle in Amoeba occurs in ………………..
9. The ……………….. in the wall of small intestine greatly increase the surface area for absorption.
10. The conversion of glucose into ……………….. during the first phase of the respiratory process occurs in the cytoplasm.
11. The conduction of the photosynthetic products is called ………………..
12. The ……………….. increases when the sucrose is transported through the phloem tissue.
13. The suction force created due to ……………….. is the main force for the conduction of water in the xylem.
14. The artery emerging from the left ventricle is called ………………..
15. There is always ……………….. blood in the right auricle.
16. As compared to blood the lymph contains ……………….. proteins.
17. The exchange of materials between the blood and tissue cells of the body takes place through ………………..
18. The terminal end of the excretory unit opens in the ………………..
19. The wall of the arteries are thick and ………………..
20. ……………….. During photosynthesis, ……………….. is evolved as by-product.

Answer:

1. glucose
2. root pressure
3. photosynthesis
4. small intestine
5. heterotrophic
6. amylase
7. acidic
8. food vacuole
9. vIlli
10. pyruvate
11. translocauon
12. osmotic pressure
13. transpiraüon
14. aorta
15. deoxygenated
16. less
17. capillaries
18. collectIng duct
19. elastic
20. oxygen

Question 4.
State whether the following statements are true or false:

1. Euglena is an autotrophic animal.
2. In human body the carbohydrates are stored in the form of glycogen.
3. In photosynthesis the carbon dioxide is oxidized to form carbohydrates.
4. The control and regulation of the opening and closing of stomata is done by the chloroplasts.
5. Liver and pancreas produce digestive juices which help in digestion in small intestine.
6. The liver secretes acidic bile.
7. The cellulose in the cells of grass, can be digested by herbivores animals.
8. The inner wall of the stomach possesses tubular glands which secrete gastric juice.
9. Cuscuta is a plant, harmful for the host plant.
10. The rate of breathing in terrestrial animals is much faster than that seen in aquatic animals.
11. Cilia help in ingestion of food in paramoecium.
12. The enzymes pepsin and trypsin digest carbohydrates and fats respectively.
13. An artificial kidney is a device to remove nitrogenous wastes from the blood through dialysis.
14. The bronchus ends in the alveolus.
15. The diaphragm bends (moves) downwards at the time of expiration.
16. The blood flows from the heart to other organs under pressure.
17. In unicellular animals, the excretory substances are removed by diffusion in the surrounding water.
18. The blood vessels absorb fat through the villi of the ileum.
19. In certain plants, the useless waste substances are stored in cellular vacuoles.
20. The wall of the blood capillaries is bilayered and thick.
21. The body temperature is maintained by using energy in animals of classes Mammalia and Aves.
22. The pulmonary arteries cany oxygenated blood.
23. In plants, the conduction of water is in both upward and downward directions.
24. The phloem tissue transports carbohydrate, amino acids and plant hormones.
25. Blood is a red coloured, non-living liquid connective tissue.

Answer:

1. True
2. True
3. False
4. False
5. True
6. False
7. True
8. True
9. True
10. False
11. True
12. False
13. True
14. False
15. False
16. True
17. True
18. False
19. True
20. False
21. True
22. False
23. False
24. True
25. False

Question 5.
Match the following:
(1)

Column I	Column II
1. Algae	p. Saprophytic nutrition
2. Cuscuta	q. Holozoic nutrition
3. Fungi	r. Autotrophic nutrition
4. Amoeba	s. Parasitic nutrition

Answer:
(1 – r), (2 – s), (3 – p), (4 – q).

(2)

Column I	Column II
1. Salivary glands	p. Beginning of protein digestion
2. Liver	q. Enzyme trypsin
3. Pancreas	r. Alkaline bile
4. Stomach	s. Secretion of amylase

Answer:
(1 – s), (2 – r). (3 – q). (4 – p).

(3)

Column I	Column II
1. Amoeba	p. Omnivores
2. Paramoecium	q. Gills
3. Human being	r. Pseudopodia
4. Fish	s. Cilia

Answer:
(1 – r), (2 – s), (3 – p), (4 – q).

(4)

Column I	Column II
1. Villi	p. Exchange of gases
2. Cartilagenous ring	q. Absorption
3. Alveolus	r. Helps in breathing
4. Diaphragm	s. Trachea

Answer:
(1 – r), (2 – s), (3 – p), (4 – q).

(5)

Column I	Column II
1. Phloem	p. Urine formation
2. Excretory unit	q. Upward and downward conduction
3. Pulmonary vein	r. Deoxygenated blood
4. Renal vein	s. Oxygenated blood

Answer:
(1 – q), (2 – p), (3 – s), (4 – r).

(6)

Column I	Column II
1. Human heart	p. Cup-shaped
2. Human kidney	q. Four-chambered
3. Nephron	r. Bean-shaped
4. Bowman’s capsule	s. Long-coiled tubule

Answer:
(1 – q), (2 – r), (3 – s), (4 – p).

(7)

Column I	Column II
1. Villi	p. Right auricle
2. Bowman’s capsule	q. Less protein
3. Lymph	r. Glomerulus
4. Vena cava	s. Small intestine

Answer:
(1 – s), (2 – r), (3 – q). (4 – p).

(8)

Column I	Column II
1. Chloroplast	p. Stomatal pore
2. Mitochondria	q. Digestion
3. Guard cells	r. Reduction of CO<sub>2</sub>
4. Food vacuole	s. Breakdown of pyruvate using O<sub>2</sub>

Answer:
(1 – r), (2 – s), (3 – p), (4 – q).

(9)

Column I	Column II
1. Photosynthesis	p. Temperature regulation
2. Respiration	q. Energy stored
3. Transpiration	r. Sucrose
4. Translocation	s. Energy released

Answer:
(1 – q), (2 – s), (3 – p), (4 – r).

Question 6.
Chart – diagram based questions:

Identify x in diagram and state which system of plant does it indicate.
Answer:
x-phloem, xylem vascular bundle, it indicates transportation system of plant.

2.

Why starch test is negative in any leaf of plant? What you conclude?
Answer:
Starch test is negative in any leaf of plant s because CO₂ is not available as the plant is in bell-jar in which KOH absorbed CO₂.
CO₂ is a raw material essential for s photosynthesis.

State the lable x and y in given diagram and also mention which life process do they indicate.
Answer:
x – pseudopodia, y – food vacuole
Life process : nutrition in amoeba

4. Fill the blanks in given table with reference to digestion process in human:

Answer:

1. Amylase
2. Protein
3. Trypsin
4. Fatty acid and glycerol

What change occurs in the solution in test tube? What is responsible for such change?
Answer:
The lime water in test tube turns milky.
We breath out CO₂ which is responsible for lime water to turn milky.

6. Fill the blanks in given chart:

Answer:

1. Xylem
2. Transpiration pull
3. Root pressure

7.

Observe the diagram and indicate which parts shows function of storage of urine and filtration of blood?
Answer:
y – kidney – filtration of blood
z – urinary bladder – storage of urine

Question 7.
Select the correct alternative from those given below each question:
1. Which of the following organism breaks down food material outside of body?
A. Mushroom
B. Cuscuta
C. Leech
D. Lice
Answer:
A. Mushroom

2. Where does the digestion of protein start in human being?
A. Mouth
B. Stomach
C. Small intestine
D. Colon
Answer:
B. Stomach

3. Which of the following type has longest small intestine?
A. Tiger
B. Human
C. Cow
D. Rat
Answer:
C. Cow

4. Which one of the following organisms can live without oxygen or air?
A. Amoeba
B. Leech
C. Green plant
D. Yeast
Answer:
D. Yeast

5. Which is the exact site for gaseous exchange s in human beings?
A. Brochus
B. Alveoli
C. Villi
D. Skin
Answer:
B. Alveoli

6. What is the product from glucose in the first phase of respiration?
A. Ethanol
B. Lactic acid
C. Pyruvic acid
D. CO₂
Answer:
C. Pyruvic acid

7. What is the ultimate purpose of digestion?
A. Transportation
B. Absorption
C. Respiration
D. Assimilation
Answer:
B. Absorption

8. Which cells surround the pore of the stomata?
A. Epidermal cells
B. Companion cells
C. Sieve cells
D. Guard cells
Answer:
D. Guard cells

9. Which organ stores bile?
A. Liver
B. Pancreas
C. Small intestine
D. Gall bladder
Answer:
D. Gall bladder

10. The enzyme acting in acidic medium is ………………..
A. amylase
B. pepsin
C. trypsin
D. both B and C
Answer:
B. pepsin

11. In plants, photosynthetic products are transported through ………………..
A. vessel and sieve tube
B. tracheid and vessel
C. sieve tube and companion cell
D. sieve tube and tracheid
Answer:
C. sieve tube and companion cell

12. In which part of the body blood is oxygenated?
A. Heart
B. Liver
C. Kidney
D. Lungs
Answer:
D. Lungs

13. At which part the actual process of filtration of blood takes place in kidney?
A. Bowman’s capsule
B. Collecting duct
C. Tubular part of nephron
D. Capillaries of nephron
Answer:
A. Bowman’s capsule

14. From which part of the human heart only oxygenated blood always flows?
A. Both atria
B. Both ventricles
C. Left atrium and left ventricle
D. Right atrium and right ventricle
Answer:
C. Left atrium and left ventricle

15. As compared to blood, the lymph contains ………………..
A. fewer RBCs
B. less amount of water
C. less amount of metabolic waste
D. less amount of proteins
Answer:
D. less amount of proteins

16. Which of the following brings oxygenated blood into left atrium in heart?
A. Pulmonary vein
B. Pulmonary artery
C. Vena cava
D. Aorta
Answer:
A. Pulmonary vein

17. What happens in the process of photo-synthesis?
A. Transformation of solar energy into functional energy
B. Transformation of solar energy into chemical energy
C. Transformation of chemical energy into functional energy
D. Transformation of functional energy into chemical energy
Answer:
B. Transformation of solar energy into chemical energy

18. Which is the main force for the conduction of water through the xylem in plants?
A. Absorption of water through roots
B. Absorption of ions through roots
C. Sufficient availability of water from the soil
D. Suction due to transpiration
Answer:
D. Suction due to transpiration

19. Which of the following alternative shows the correct path of oxygenated blood flow in human beings?
A. Lungs → Pulmonary veins → Left auricle → Left ventricle → Various organs of the body
B. Lungs Pulmonary artery → Left auricle → Left ventricle → Various organs of the body
C. Lungs → Pulmonary artery → Right auricle → Right ventricle → Various organs of the body
D. Various organs of the body Right auricle → Right ventricle → Pulmonary artery → Lungs
Answer:
A. Lungs → Pulmonary veins → Left auricle → Left ventricle → Various organs of the body

20. Select the correct pair :
A. Stomata – transpiration
B. Translocation – glucose
C. Villi – egestion of feaces
D. Trachea – cartilaginous rings
Answer:
A. Stomata – transpiration
D. Trachea – cartilaginous rings

21. Which process is important for osmoregulation?
A. Nutrition
B. Circulation
C. Breathing
D. Excretion
Answer:
D. Excretion

22. Which one is the false statement for arteries?
A. Arteries carry blood from the heart towards other organs.
B. In arteries the blood flows under high pressure.
C. All arteries carry oxygenated blood.
D. The arterial walls are thick and elastic.
Answer:
C. All arteries carry oxygenated blood.

23. Resin and gum are the substances of plants.
A. excretory
B. nutritive
C. constitutional
D. reserve
Answer:
A. excretory

24. Which is the circulatory pathway of blood in the human heart?
A. Right auricle → Left auricle → Lungs → Right ventricle → Left ventricle → Different organs
B. Right auricle → Right ventricle → Lungs → Left auricle → Left ventricle → Different organs
C. Right auricle → Right ventricle Different organs → Left auricles Left ventricle → Lungs
D. Right auricle → Left auricle → Different organs → Right ventricle → Left ventricle → Lungs
Answer:
B. Right auricle → Right ventricle → Lungs → Left auricle → Left ventricle → Different organs

25. Which substance does not get reabsorbed in nephron during urine formation?
A. Glucose
B. Urea
C. Amino acid
D. Uric acid
Answer:
B. Urea, Uric acid

26. In which of following process. ATP is used?
A. Translocation of food
B. To maintain body temperature in human
C. Respiration
D. Simple diffusion in human
Answer:
Translocation of food, To maintain body temperature in human

27. Statement A: The rate of breathing is much faster in fishes.
Reason R : The blood goes only once through the heart in the fish during one cycle of passage through the body.
Which is the correct option for Statement A and Reason R?
A. Both A and R correct and R is explanation of A.
B. Both A and R correct but R is not explanation of A.
C. A is correct, R is incorrect.
D. A is incorrect, R is correct.
E. Both A and R incorrect.
Answer:
A. Both A and R correct and R is explanation of A.

28. Statement A : ATP is the energy currency for cellular processes.
Reason R: Complete oxidation of pyruvate in presence of oxygen occurs in mitochondria.
Which is the correct option for Statement A and Reason R?
A. Both A and R correct and R is explanation of A.
B. Both A and R correct but R is not explanation of A.
C. A is correct, R is incorrect.
D. A is incorrect, R is correct.
E. Both A and R incorrect.
Answer:
B. Both A and R correct but R is not explanation of A.

29. Which animals tolerate some mixing of oxygenated and deoxygenated blood streams?
A. Fishes
B. Birds
C. Mammals
D. Amphibians
Answer:
D. Amphibians

30. The diagram is labelled, which part secretes digestive juice?

A. 1, 3, 5, 7
B. 2, 4. 6, 8
C. 2, 3, 5, 8
D. 1, 4, 6, 8
Answer:
A. 1, 3, 5, 7

Question 8.
Answer as directed : (Miscellaneous)
(1) Which pigment has a very high affinity for oxygen? Where is it present in human body?
Answer:
Haemoglobin in red blood cells

(2) State the equation of photosynthesis.
Answer:

(3) Name of instrument used to measure blood pressure.
Answer:
Sphygmomanometer

(4) About which organism there is a controversy regarding whether it is a living being or non-living entity?
Answer:
Viruses

(5) Give the full form of ATP.
Answer:
Adenosine TriPhosphate

(6) Identify me : I am a cup-shaped structure with glomerulus and I carry out filtration.
Answer:
Bowman’s capsule

(7) Find mismatched pair :
1. One cell thick – blood capillary
2. Ring of cartilage – trachea
3. Phloem tissue – transport of sucrose
4. Platelet cells – transport of respiratory gases
Answer:
4. Platelet cells – transport of respiratory gases

(8) State the normal blood pressure of human.
Answer:
Systolic pressure 120 mm Hg and diastolic pressure 80 mm Hg

(9) Identify me : A component of gastric juice protect the inner lining of the stomach from the action of hydrochloric acid under normal condition.
Answer:
Mucus

(10) Sketch the respiratory pathway which does not produce CO₂.
Answer:

(11) Which of the following organisms show parasitic nutritive strategy?
Lion, lice, bread mould, cuscuta, leech, yeast, tick
Answer:
lice, cuscuta, leech, tick

(12) Find mismatched pair:
1. Paramoecium – Fermentation
2. Peristaltic movement – All along the gut
3. Emulsifying action – Bile
4. Trachea – Windpipe
Answer:
1. Paramoecium – Fermentation

(13) Which treatment do you suggest to a patient whose both kidneys have stopped functioning?
Answer:
Hemodialysis

(14) Transpiration helps to create osmotic pressure for translocation of sucrose. State whether s this sentence true or false.
Answer:
False

Value Based Questions With Answers

Question 1.
Your younger brother complains about pain in teeth. You often notice that he frequently eats chocolates and pastries. Even he likes to eat sweets.
Questions:

1. What do you think about the pain in teeth?
2. Which advise will you give to your brother?
3. What will happen if this problem is untreated?

Answer:

1. Sugar content is very high in chocolates, pastries and sweets. Bacteria act on sugars and produce acidic substances. Acids soften? the enamel, i.e.. cause dental caries or tooth decay. Masses of bacterial cells together with food particles stick to the teeth to form dental plaque. This is responsible for pain in teeth.
2. Brushing the teeth after eating, will remove plaque.
3. If this problem is untreated, microorganisms may invade the gums causing inflammation and infection

Question 2.
Your uncle often complains about indigestion of after having oily food. He consults a doctor and? is diagnosed with stone in gall bladder. Doctor advised him to remove gall bladder surgically.
Questions:

1. What is the function of gall bladder?
2. Which process initiates the digestion of oils?
3. After surgery, which type of food should be given to uncle?

Answer:

1. Gall bladder stores bile juice.
2. Emulsification (i.e.. bile salts breakdown large 5 oil globules into fine small droplets) process initiate the digestion of oils.
3. After surgery, food with low fat content, i.e., less oil, ghee, butter, etc. is advisable.

Question 3.
Your neighbour is a chain-smoker. He often suffers from cough and lung infection. His relatives often tell him to leave smoking.

Questions:

1. How inhaled air is filtered in the upper part of respiratory tract?
2. Which is the effect of smoking on the upper part of respiratory tract?
3. Why do you call smoking as injurious to health?

Answer:

1. The upper part of respiratory tract is provided with small hair-like structures called cilia, which help to remove germs, dust and other harmful particles from inhaled air.
2. Smoking destroys hair like cilia due to which germs, dust, smoke and other harmful chemicals enter lungs and causes harm.
3. Smoking reduces the breathing efficiency of lungs, may cause various infection and even lung cancer. So, called it is injurious to health. Cigarette contains nicotine which can cause cancer to the respiratory organs.

Question 4.
Your subject teacher arranges a visit to a hospital, where you can observe haemodialysis.

Questions :

1. Which conditions may lead to kidney failure?
2. What is the use of artificial kidney?
3. Explain how artificial kidneys work?

Answer:

1. Several factors such as infections, injury or restricted blood flow to kidney reduce the activity of kidneys. This leads to accumulation of toxic nitrogenous substances, gradually may lead to kidney failure.
2. An artificial kidney is a device to remove s nitrogenous waste products from the blood through dialysis.
3. Artificial kidneys contain a number of tubes with a semi-permeable lining, suspended in a tank filled with dialysing fluid. This fluid has same osmotic pressure as blood but nitrogenous wastes are absent.

As shown in diagram, patient’s blood is passed through tubes. During this, nitrogenous waste products from blood pass into dialysing fluid by diffusion. The purified blood is pumped back into the patient’s vein.

Practical Skill Based Questions With Answers

Question 1.
Observe experiment arranged in your school laboratory as shown in figure.

Questions :

1. State the colour of the stem and veins of the leaves.
2. Does the volume of solution in the beaker get reduced? Why?
3. In the T.S. of stem, which part is observed to be reddish in colour? Why?
4. State your inference.

Answer:

1. Reddish
2. Yes, because plant absorbed solution from beaker through its roots.
3. Xylem tissue becomes reddish in colour in T.S. of stem because water moves up through xylem.
4. Water and minerals absorbed by root move in upward direction through xylem vessels.

Question 2.
Take a potted plant.

• Insert one of its branches in a large, thin and transparent plastic/polythene bag and tie the bag at its open end with the branch.
• Add adequate amount of water to the clay in the pot, and keep the pot exposed to sunlight for a few hours.
• Observe the inner side of the bag after a few hours.
  

Questions :

1. Why are small droplets of water seen on the inner surface of the plastic/polythene bag?
2. State the role played by sunlight in the formation of water droplets.
3. State the passage of flow of water droplets through the potted plant.

Answer:

1. Loss of water vapour from leaves condense and show water droplets.
2. Sunlight is responsible for transpiration. Water is lost in the form of vapour, which creates suction and transpiration pull in upward direction.
3. Soil root xylem → stem-xylem → leaf xylem → stomata → water vapour

Question 3.
Place two fingers of your right hand on the left wrist and feel the pulse beats.

• Count the number of pulse beats felt by your right hand fingers in exactly one minute.
• Repeat the counting of pulse beats twice or thrice for accuracy. Find out the mean of all readings.
• Now run fast for a short distance for about one or two minutes, or climb the steps of a staircase quite rapidly twice or thrice.
• And thereafter, again measure your pulse s beats.

Questions:

1. State the normal pulse rate.
2. State the relation of pulse rate with the rate of heart beats.
3. State the number of pulse beats after a little running or climbing the staircase.
4. What is the change found in the pulse rate after running, as compared to the normal pulse rate? Why?

Answer:

1. 60- 100
2. The pulse rate is similar to heart beats.
3. 120 to 130 times in a minute.
4. Pulse rate increases after riming because body requires more oxygen and to fullfil it, heart beats increase.

Memory Map:

Jharkhand Board JAC Class 10 Science Solutions Chapter 5 Periodic Classification of Elements Textbook Exercise Questions and Answers.

JAC Board Class 10 Science Solutions Chapter 5 Periodic Classification of Elements

Jharkhand Board Class 10 Science Periodic Classification of Elements Textbook Questions and Answers

Question 1.
Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic table :
(a) The elements become less metallic in nature.
(b) The number of valence electrons increases.
(c) The atoms lose their electrons more easily.
(d) The oxides become more acidic.
Answer:
The atoms lose their electrons more easily.

Question 2.
Element X forms a chloride with the formula XCl₂, which is a solid with a high melting point. X would most likely be in the same group of the periodic table as…
(a) Na
(b) Mg
(c) Al
(d) Si
Answer:
Mg

Question 3.
Which element has
(a) two shells, both of which are completely filled with electrons?
(b) the electronic configuration 2, 8, 2?
(c) a total of three shells, with four electrons in its valence shell?
(d) a total of two shells, with three electrons in its valence shell?
(e) twice as many electrons in its second? shell as in its first shell?
Answer:
(a) Neon (2, 8)
(b) Magnesium (2, 8, 2)
(c) Silicon (2, 8, 4)
(d) Boron (2, 3)
(e) Carbon (2, 4)

Question 4.
(a) What property do all elements in the same column of the periodic table as boron have in common?
(b) What property do all elements in the same column of the periodic table as fluorine have in common?
Answer:
(a) In the modern periodic table, Boron is an element of group 13. Its valency is 3. Thus, all other elements of this group have valency 3.

(b) In the modern periodic table, fluorine is an element of group 17. All the elements of this group have 7 electrons in their valence shells. Therefore, the valency of all elements of this group is 1.

Question 5.
An atom has electronic configuration 2, 8, 7.
(a) What is the atomic number of this element?
(b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
N (7) F (9) P (15) Ar (18)
Answer:
(a) The atomic number of this element is 17(2 + 8 + 7).
(b) F (9) [ ∵ Electronic configuration of F is 2, 7.]

Question 6.
The position of three elements A, B and C in the periodic table are shown below:

Group	Group 17
–	–
–	A
–	–
B	C

(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?
Answer:
(a) Element A is an element of group 17. There are 7 electrons in their valence shell and thus by gaining one more electron it acquire a complete octet. Thus, an element A is a non-metal.

(b) On going down in a group, the atomic s size increases. Therefore, the force of attraction of the nucleus on the incoming electron decreases. As a result, reactivity decreases down the group. Since element C has larger atomic size than A, the element C is less reactive than the element A. In reference of forming positive ion, element C is more reactive than the element A.

(c) Elements B and C belong to the same period. On moving left to right in a period, atomic size (volume) decreases. Thus, the atomic size of C is smaller than B.

(d) Since element A has 7 electrons in the valence shell, it has a tendency to gain one electron to complete its octet. Thus, element A forms an anion.
A + \(\overline{\mathrm{e}}\) → A^–

Question 7.
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the periodic table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
Answer:
The electronic configuration of nitrogen and phosphorus are as follows:

Element	Atomic number	Electronic configuration
		K	L	M
Nitrogen (N)	7	2	5	–
Phosphorus (P)	15	2	8	5

Nitrogen is more electronegative than phosphorus because electronegative character decreases on moving down a group.

Question 8.
How does the electronic configuration of an atom relate to its position in the modern periodic table?
Answer:
In the periodic table, position of an element depends on its electronic configuration. The position of an element can be determined by knowing the number of valence electron in its electronic configuration.
For example,

Possesses one electron in its valence shell. Hence, it belongs to group 1.
→ The number of shells in the electronic configuration of an element determines its position in a period.
For example,

has three shells (K, L and M). So, it belongs to 3rd period of the periodic table.

Question 9.
In the modern periodic table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?
Answer:

Element	Atomic number	Electronic configuration
		k	L	M	N	O
Calcium	20	2	8	8	2	–
Magnesium	12	2	8	2	–	–
Potassium	19	2	8	8	1	–
Scandium	21	2	8	8	3	–
Strontium	38	2	8	18	8	–

Elements with atomic number 12 and 38 have 2 electrons in their last shell like calcium. So, they will resemble Ca in their chemical properties.

Question 10.
Compare and contrast the arrangement of elements in Mendeleev’s periodic table and the modern periodic table.
Answer:

Mendeleev’s periodic table	Modern periodic table
1. Mendeleev’s periodic table consists of seven periods and eight groups.	1. Modern periodic table consists of seven periods and eighteen groups.
2. Transition elements are not separated in the Mendeleev’s periodic table.	2. Transition elements are placed in a separate groups in the modern periodic table.
3. In Mendeleev’s periodic table, elements are arranged in increasing order of their atomic masses.	3. In the modern periodic table, elements are arranged in increasing order of their atomic numbers.
4. Period number and group number of an element cannot be predicted.	4. Period number and group number of an element can be determined easily.
5. Mendeleev’s periodic table has descripancies and limitations.	5. Modern periodic table is almost errorless.
6. Periodicity in the properties of elements cannot be explained.	6. Periodicity in the properties of elements can be explained.

Jharkhand Board Class 10 Science Periodic Classification of Elements InText Questions and Answers

Question 1.
Did Dobereiner’s triads also exist in the columns of Newlands’ octaves? Compare and find out.
Answer:
Dobereiner’s triads also exist in the columns of Newlands’ octaves.

• Lithium, sodium and potassium forms a Dobereiner’s triad.
• Lithium, the first element of this triad is considered as the first element as Newlands’ octave, then the eighth element from it is sodium. These elements possesses similar properties according to the law of triads and the law of octaves.
• Similarly, if sodium is considered as the first element then the eighth element from it is potassium.  Moreover, sodium and potassium possess similar properties according to both the laws.
• Apart from these, some other elements beryllium (Be), magnesium (Mg) and calcium (Ca) obeys law of triads and the law of octaves.
• Thus, Dobereiner’s triads also exist in the columns of Newlands’ octaves.

Question 2.
What were the limitations of Dobereiner’s classification?
Answer:
The limitations of Dobereiner’s classification are as follows:

• All the elements known at that time could not be arranged as Dobereiner’s triad. Hence this method of classification of elements into triads was not found to be successful.
• Three elements nitrogen (N), phosphorus (P) and arsenic (As) were then known elements, but these elements could not be classified as Dobereiner’s triad.

Question 3.
What were the limitations of Newlands’ law of octaves?
Answer:

• Newlands’ law of octaves was applicable only to lighter elements having atomic masses up to 40 u.
  The law of octaves was applicable only s upto calcium, because after calcium every eighth element did not possess properties similar to that of the first element.
• Newlands assumed that only 56 elements s existed in nature and no new elements would be discovered in the future. But, later on, several new elements were discovered whose properties did not fit into the law of octaves.
• In order to fit elements into his table, Newlands adjusted two elements in the same slot, but also put some unlike elements under the same column.

For example, cobalt (Co) and nickel S (Ni) are placed in the same slot and these are placed in the same column as fluorine, chlorine and bromine which have very different properties S than these elements. Iron, which resembles cobalt and nickel in properties, has been placed far away from these elements.

Question 4.
Use Mendeleev’s periodic table to predict the formulae for the oxides of the following elements:
K, C, Al, Si, Ba
Answer:

Element	Group number (Valency)	Molecular formula of oxide
K	1	K<sub>2</sub>O
C	4	CO2
Al	3	Al2O3
Si	4	SiO2
Ba	2	BaO

Question 5.
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his periodic table? (any two)
Answer:
Besides gallium, Mendeleev had left gaps for germanium and scandium in his periodic table.

Question 6.
What were the criteria used by Mendeleev in creating his periodic table?
Answer:
The following criteria was used by Mendeleev in creating his periodic table :

• The properties of elements are the periodic function of their atomic masses.
• Elements with similar properties are arranged in the same group.
• The formula of oxides and hydrides formed by an element.

Question 7.
Why do you think the noble gases are placed in a separate group?
Answer:
Noble gases like helium (He), neon (Ne) and argon (Ar) are chemically very inert and are present in extremely low concentrations in our atmosphere. Hence they are placed in a separate s group.

Question 8.
How could the modern periodic table remove various anomalies of Mendeleev’s periodic table?
Answer:
The modern periodic table removed three main anomalies of Mendeleev’s periodic table as discussed below:
(1) Position of isotopes : All the isotopes of an element have the same atomic number. Therefore, they are placed at one place in the same group of the periodic table.

(2) Anomalous position of some pairs of elements: In the Mendeleev’s periodic table, elements with similar properties are placed in the same group. For example, cobalt (atomic mass 58.9 u) placed first and nickel (atomic mass 58.7 u) placed later while in the modern periodic table elements are arranged in increasing order of their atomic numbers, therefore, cobalt with atomic number 27 placed first and nickel with atomic number 28 placed later.

(3) Uncertainty in discovery of new elements: Since atomic masses do not increase in a regular manner in going from one element to the next, therefore, in Mendeleev’s periodic table, it was not possible to predict as to how many new elements could be discovered between two known elements.

Since, modern periodic table is formed on the basis of atomic numbers of elements, discovery of new element become easy.

Question 9.
Name two elements you would expect to show chemical reactions similar to magnesium. What is the basis for your choice?
Answer:
In the modern periodic table, elements having same number of electrons in the valence shell show similar chemical properties.
Magnesium has two electrons in the valence shell, hence all the elements such as beryllium (Be), calcium (Ca) and strontium (Sr) having two electrons in the valence shell show similar chemical properties.

Elements of group 2
Element	Atomic number	Electronic configuration
		K	L	M	N	O
Beryllium (Be)	4	2	2
Magnesium (Mg)	12	2	8	2
Calcium (Ca)	20	2	8	8	2
Strontium (Sr)	38	2	8	18	8	2

Question 10.
Name :
(a) three elements that have a single electron in their outermost shells.
(b) two elements that have two electrons in their outermost shells.
(c) three elements with filled outermost shells.
Answer:
(a) Lithium (Li), sodium (Na) and potassium (K)
(b) Magnesium (Mg) and calcium (Ca)
(c) Neon (Ne), argon (Ar) and krypton (Kr)

Question 11.
(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the? atoms of these elements?
(b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?
Answer:
(a) Lithium, sodium and potassium are alkali metals which react with water to form metal hydroxides with the release of hydrogen gas.
2M + 2H₂O → 2MOH + H₂
Where, M = Li, Na and K
All these metals have one electron in their respective valence shells.

(b) Helium and neon are noble gases. Both the elements have their outermost shells completely filled. Helium has only K shell which is complete with 2 electrons while neon has two shells, K and L. Both these shells are complete, i.e., K s shell has 2 electrons and L shell has 8 electrons.

Question 12.
In the modern periodic table, which are the metals among the first ten elements?
Answer:
The first ten elements of the modern periodic table are as follows :
₁H, ₂He, ₃Li, ₄Be, ₅B, ₆C, ₇N, ₈O, ₉F and ₁₀Ne.
Among these elements Li and Be are metals.

Question 13.
By considering their position in the periodic table, which one of the following elements would you expect to have maximum metallic characteristics?
Ga Ge As Se Be
Answer:
Among the given elements, Be and Ga will show maximum metallic characteristics.
The arrangement of given elements in different groups and periods is as follows :

Activity 5.1 [T. B. Pg. 84]

Looking at its resemblance to alkali metals and the halogen family, try to assign hydrogen a : correct position in Mendeleev’s periodic table.
To which group and period should hydrogen be assigned ?

Discussion:

• Hydrogen is an element having lowest atomic number (Z = 1) and lowest atomic mass (1.008 u).
• The electronic configuration of hydrogen resembles with alkali metals.
• Like alkali metals, hydrogen combines with halogens, oxygen and sulphur to form compounds having similar molecular formulae. Hence, hydrogen can be placed along with alkali metals of group (IA).
• Hydrogen exists as a diatomic molecule like halogens and it combines with alkali metals to form ionic compounds and with non-metals to form covalent compounds.
• Thus, hydrogen should be placed along with halogens in group (VII).

Conclusion :
The position of hydrogen in the periodic table is controversial, however, it would be more appropriate to place it in group I and period I.

Activity 5.2 [T. B. Pg. 85]

• Consider the isotopes of chlorine, Cl-35 and Cl-37.
• There are two known isotopes of chlorine : Cl-35 and Cl-37.
• The atomic number of these two isotopes is 17, hence they have similar electronic configuration and chemical properties, but their atomic masses are different.

Questions :

Question 1.
Would you place them in different slots because their atomic masses are different?
Answer:
According to Mendeleev’s periodic table, “The properties of elements are the periodic function of their atomic masses.”

• According to Mendeleev, if these two isotopes are arranged in the order of increasing atomic masses, then their position should be before K(39.1u), but there is no vacant position available for Cl-37 in between Cl-35 and K(39.1u). Therefore they cannot be placed at the different position.

Question 2.
Would you place them in the same position because their chemical properties are the same?
Answer:
As they have similar chemical properties, they should be placed at the same position in group 17.

Activity 5.3 [T. B. Pg. 85]

Questions:

Question 1.
How were the positions of cobalt and nickel resolved in the modern periodic table?
Answer:

• In modern periodic table, elements are arranged in increasing order of their atomic numbers.
• The atomic number of cobalt and nickel are 27 and 28 respectively. Hence, on the basis of increasing order of their atomic numbers, cobalt is placed s in group 9 and nickel is placed in group 10.

Question 2.
How were the positions of isotopes of various elements decided in the modern periodic table?
Answer:
In the modern periodic table, positions of isotopes of different elements are not fixed separately. Since the various isotopes of an element have the same atomic number, they are assigned the same position in the modern periodic table.

Question 3.
Is it possible to have an element with atomic number 1.5 placed between hydrogen and helium?
Answer:

• The atomic number of an element is always definite and whole number.
• In the modern periodic table, elements are arranged in increasing order of their atomic numbers.
• The atomic number cannot be represented in fraction number. Thus, an element with atomic number 1.5 cannot be placed between hydrogen S and helium.

Question 4.
Where do you think should hydrogen be placed in the modern periodic table?
Answer:
Hydrogen should be placed in period and group 1 in the modern periodic table, $ since it has atomic number one.

Activity 5.4 [T. B. Pg. 87]

Questions:

Question 1.
Look at the group 1 of the modern periodic table and name the elements present in it.
Answer:
The names of the elements present in group 1 are: hydrogen (H), lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) and francium (Fr).

Question 2.
Write down the electronic configuration of the first three elements of group 1.
Answer:
The electronic configuration of the first three elements are as follows :

Element	H	Li	Na
Shell	K	K, L	K, L, M
Electronic configuration	1	2, 1	2, 8, 1

Question 3.
What similarity do you find in their electronic configurations?
Answer:
These elements possesses same number of electrons in their valence shell.

Question 4.
How many valence electrons are present in these three elements?
Answer:
These three elements have one electron in their respective valence shell.

Activity 5.5 [T. B. Pg. 87]

Questions:

Question 1.
If you look at the modern periodic table, you will find that the elements Li, Be, B, C, N, O, F and Ne are present in the second period. Write down their electronic configurations.
Answer:

Element	3Li	4Be	5B	6C	7NN	8O	9F	10Ne
Shell	K, L	K, L	K, L	K, L	K, L	K, L	K, L	K, L
Electronic configuration	2, 1	2, 2	2, 3	2, 4	2, 5	2, 6	2, 7	2, 8

Question 2.
Do these elements also contain the same number of valence electrons?
Answer:
These elements do not contain the same number of valence electrons.

Question 3.
Do they contain the same number of shells?
Answer:
These elements contain the same number of shells (2, K and L).

Activity 5.6 [T. B. Pg. 88]

Questions :

Question 1.
How do you calculate the valency of an element from its electronic configuration?
Answer:
The valency of an element is determined by the number of valence electrons present in the outermost shell of the atom.
For elements of group 1, 2, 13 and 14, the valency is equal to the number of valence electrons and for elements of group 15, 16, 17 and 18, the valency is equal to 8 minus number of valence electrons.

Question 2.
What is the valency of magnesium with atomic number 12 and sulphur with atomic number 16?
Answer:
Electronic configuration of Mg with atomic number 12 is K L M 2 8 2
∴ Valency of Mg = 2
Electronic configuration of S with atomic number 16 is K L M 2 8 6
∴ Valency of S = 8 – 6 = 2

Question 3.
Find the valency of the first twenty elements.
Answer:

Element	Atomic number	Group number	Electronic configuration				Number of valence electrons	Valency of the element
			K	L	M	N
H	1	1	1				1	1
He	2	18	2				2	2-2 = 0
Li	3	1	2	1			1	1
Be	4	2	2	2			2	2
B	5	13	2	3			3	3
C	6	14	2	4			4	4
N	7	15	2	5			5	8-5 = 3
O	8	16	2	6			6	8-6 = 2
F	9	17	2	7			7	8-7=1
Ne	10	18	2	8			8	8-8 = 0
Na	11	1	2	8	1		1	1
Mg	12	2	2	8	2		2	2
Al	13	13	2	8	3		3	3
Si	14	14	2	8	4		4	4
P	15	15	2	8	5		5	8-5 = 3
S	16	16	2	8	6		6	8-6 = 2
Cl	17	17	2	8	7		7	8-7=1
Ar	18	18	2	8	8		8	8-8 = 0
K	19	1	2	8	8	1	1	1
Ca	20	2	2	8	8	2	2	2

Question 4.
How does the valency vary in a period on going from left to right?
Answer:
In a period, the valency first increases and then decreases. In a period, the valency first increases from 1 to 4 and then decreases from 4 to 0.

Question 5.
How does the valency vary in going down a group?
Answer:
On moving down the group, the valency does not change. It remains constant.

Activity 5.7 [T. B. Pg. 88]

Questions:

Question 1.
Atomic radii of the elements of the second period are given below:

Period II elements:	B	Be	O	N	Li	C
Atomic radius (pm):	88	111	66	74	152	77

Arrange them in decreasing order of their atomic radii.
Answer:
Decreasing order of the atomic radii:
Period II elements : Li > Be > B > C > N > O
Atomic radius (pm) : 152  111 88 77 74 66

Question 2.
Are the elements now arranged in the pattern of a period in the periodic table?
Answer:
Now, the above elements are arranged in the pattern of a period in the periodic table.

Question 3.
Which elements have the largest and the smallest atoms?
Answer:
Lithium (Li) has the largest and oxygen (O) has the smallest atoms.

Question 4.
How does the atomic radius change as you go from left to right in a period?
Answer:
The atomic radii decreases as we move from left to right in a period.

Activity 5.8 [T. B. Pg. 89]

Questions:

Question 1.
Study the variation in the atomic radii of ? first group elements given below and arrange them in an increasing order.

Group I elements :	Na	Li	Rb	Cs	K
Atomic radius (pm):	186	152	244	262	231

Answer:
Increasing order of the atomic radii:
Group I elements : Li < Na < K < Rb < Cs
Atomic radius (pm): 152 186 231 244 262

Question 2.
Name the elements which have the smallest and the largest atoms.
Answer:
Lithium (Li) has the smallest atoms while Cesium (Cs) has the largest atoms.

Question 3.
How does the atomic size vary as you go down a group ?
Answer:
As we go down a group, the atomic size increases gradually.

Activity 5.9 [T. B. Pg. 89 ]

Questions:

Question 1.
Examine elements of the third period and classify them as metals and non-metals.
Answer:
The elements of the third period :

Question 2.
On which side of the periodic table do you find the metals?
Answer:
Metals are present on the left side of the periodic table.

Question 3.
On which side of the periodic table do you find the non-metals?
Answer:
Non-metals are present on the right side of the periodic table.

Activity 5.10 [T. B. Pg. 89]

Questions:

Question 1.
How do you think the tendency to lose electrons changes in a group?
Answer:
As we move from top to bottom in a group, the tendency to lose electrons increases.

Question 2.
How will this tendency change in a period?
Answer:
As we move from left to right in a period, the tendency to lose electrons decreases.

Activity 5.11 [T.B.Pg. 90]

Questions:

Question 1.
How would the tendency to gain electrons change as you go from left to right across a period?
Answer:
As we go from left to right across a period, the tendency to gain electrons increases.

Question 2.
How would the tendency to gain electrons change as you go down a group?
Answer:
As we go down a group, the tendency to gain electrons decreases.

JAC Board Class 9th Social Science Important Questions Geography Chapter 4 Climate

I. Objective Type Questions

India has which type of climate?
(a) Monsoon
(b) Tundra
(c) Savanna
(d) Mediterranean.
Answer:
(a) Monsoon

2. The major factor/factors controlling the climate of any region is/are:
(a) latitude
(b) altitude
(c) pressure and wind system
(d) all of these.
Answer:
(d) all of these.

3. The climate of India is strongly influenced by:
(a) local winds
(b) monsoon winds
(c) westerlies winds
(d) none of these.
Answer:
(b) monsoon winds

4. How many seasons can be indentified in India?
(a) Four
(b) Five
(c) Two
(d) Six.
Answer:
(a) Four

5. Which is the most rainy place in the world?
(a) Jaipur
(b) Leh
(c) Mawsynram
(d) Mumbai.
Answer:
(c) Mawsynram

II. Very Short Answer Type Questions

Question 1.
Define weather and climate.
Answer:
Weather refers to the state of the atmosphere over an area at any point of time, while climate refers to the sum total of weather conditions and variations over a large area for a longer period of time.

Question 2.
Define Monsoon.
Answer:
The word ‘Monsoon’ is derived from the Arabic word ‘Mausim’, which literally means season. Monsoon refers to the seasonal reversal in the wind direction during a year. It reveals the rhythm of season and changes in direction of wind.

Question 3.
What is extreme climate?
Answer:
The climate which has high annual range of temperature and great variation in the amount of rainfall over the year is known as extreme climate. It is also called continental or interior climate. Example Jodhpur, Delhi.

Question 3.
Mention major factors affecting the climate of our country.
Answer:

1. Location,
2. Latitude,
3. Altitude,
4. Pressure and winds,
5. Relief.

Question 4.
Which physical feature of India acts as an influential climate divide between India and Central sea?
Answer:
The Himalayas.

Question 5.
Name the planatery winds that blow from the subtropical high pressure zone to the equatorial low pressure zone.
Answer:
Trade winds.

Question 6.
What are trade winds?
Answer:
Trade winds are planetary winds blowing constantly from the sub-tropical high pressure zones towards the ‘Equatorial low pressure zones’. Their direction is from North-east to South-west in the North Hemisphere and from South-east to Northwest in the Southern Hemisphere.

Question 7.
Define the term season.
Answer:
The predominance of an element of weather, such as temperature, rainfall and cloudiness over a period of a few months is called season.

Question 8.
What do you understand by coriolis force?
Answer:
Coriolis force is an apparent force caused by the earth’s rotation. The coriolis force is responsible for deflecting winds towards the right in the Northern Hemisphere and towards the left in the Southern Hemisphere. This is also known as ‘Ferrel’s Law’.

Question 9.
Which are the most constant jet streams?
Answer:

1. Mid latitude jet stream,
2. Subtropical jet stream.

Question 10.
What are cyclones?
Answer:
Cyclones are the speedy elliptical wind arrangements having low pressure at their centre and the winds moving towards centre from outside.

Question 11.
From where the western disturbances originated?
Answer:
The western disturbances originated over the Mediterranean Sea.

Question 12.
What is ITCZ?
Answer:
The Inter Tropical Convergence Zone (ITCZ) is a broad trough of low pressure in equatorial latitudes. This is where the north-east and the south-east trade winds converge. This convergence zone lies more or less parallel to the equator but moves north or south with the apparent movement of the sun.

Question 13.
What is the influence area of the monsoon?
Answer:
Regions between 20° N and 20° S latitudes.

Question 14.
How is the intensity of monsoons predicted?
Answer:
The difference in pressure over yahiti (Pacific Ocean, 18°S/14.9°W) and Darwin in Northern Australia (Indian Ocean, 12°30’S/131°E) is computed to predict the intensity of the monsoons. If the pressure differences are negative, it would mean below average and late monsoons.

Question 15.
Name the two branches in which the peninsular India divide the monsoon winds.
Answer:

1. The Arabian Sea Branch, and
2. The Bay of Bengal branch.

Question 16.
Name two branches in which the Bay of Bengal branch splits into.
Answer:

1. The western branch,
2. The north-east branch.

Question 17.
What is burst of monsoon?
Answer:
Burst or break of the monsoon is sudden setting-in of rainfall, the rainfall without warning. This occurs when the monsoon branches and the jet streams come into contact with each other all of a sudden.

Question 18.
Name the four seasons of India.
Answer:

1. Winter season (December to February)
2. Summer season (March to May)
3. Advancing monsoon (June to mid-September)
4. Retreating monsoon (mid-September to November).

Question 19.
Where is high pressure found during winter?
Answer:
In the Northern plains.

Question 20.
Name the winds that blow in India during winter.
Answer:
North-east trade winds.

Question 21.
Which hot wind blows during summers in the northern plains?
Answer:
Loo.

Question 22.
What is Loo?
Answer:
Loo are local hot winds which blow during summer afternoons in the north-west and the Ganga valley regions.

Question 23.
What is Kaal Baisakhi?
Answer:
Localised thunderstorms associated with violent winds, torrential downpour, and often accompanied by hails during summer months in West Bengal are known as Kaal Baisakhi, meaning calamity for the month of Baisakh.

Question 24.
What are mango showers?
Answer:
The pre-monsoon showers occuring on the coastal regions of Kerala and Karnataka which help early ripening of mango fruit, are called mango showers.

Question 25.
What type of rainfall does the North-east Branch cause?
Answer:
Heavy rainfall.

Question 26.
Define precipitation.
Answer:
Precipitation is the moisture shed by the moisture-laden winds on the surface of the earth. Precipitation includes rainfall, snowfall, hail, sleet etc.

Question 27.
Mention the two heaviest rainfall areas of the country.
Answer:

1. The windward slopes of the Western Ghats.
2. The Meghalaya plateau.

Question 28.
Name the place where the heaviest rainfall of the world occurs.
Answer:
Mawsynram (1080 cm).

Question 29.
Which monsoon winds cause rains generally on the Tamil Nadu coast?
Answer:
Retreating monsoon winds and north-east monsoon winds.

Question 30.
What is known as ‘October Heat’?
Answer:
Conditions of high temperature, humidity and lack of air movement lead to oppres¬sive weather conditions in the half of the October. This is known as October Heat.

III. Short Answer Type Questions

Question 1.
What is the coriolis force? State its effects on the world climate.
Answer:
Meaning of Coriolis Force: It is an apparent force caused by the Earth’s rotation. It is responsible for deflecting winds towards the right in the Northern hemisphere and towards the left in the Southern hemisphere.

Effect of Coriolis Force on the World Climate: Under the effect of coriolis force, the trade winds moving from sub-tropical high-pressure belts to equatorial low-pressure belts become North-East trade winds in the Northern hemisphere and South-East trade winds in the Southern hemisphere. As a result, they bring heavy rainfall to the Eastern Coast, while the Western Coast remains dry.

Question 2.
The pressure and wind conditions over India are unique’. Explain.
Answer:

1. During winter, there develops a high pressure area in the north of the Himalayas, cold dry winds blow from this region to the low pressure areas over the ocean to the south.
2. In summer, a low pressure area develops over interior Asia as well as over north western India. This causes a complete reversal of the direction of winds during sum¬mer. These winds are known as south-west monsoon winds. These bring widespread rainfall over the mainland of India.

Question 3.
What are western cyclonic disturbances? Describe its effect on the Indian climate. Answer:The western cyclonic disturbances are weather phenomena brought in by westerly flow from the Mediterranean region. They occur in the month of winter and cause rainfall in North and North-Western part of India. They affect the climate of India in the following ways:

1. By causing cyclonic rainfall in the month of winter, which is otherwise dry, western disturbance influences the weather of the North and North-Western India.
2. Although the amount of rainfall is scant, it is highly favourable to the Rabi crops, especially wheat.
3. They cause snowfall in the mountains.

Question 4.
What do you understand by the southern oscillation?
Answer:
The pressure systems of Pacific Ocean and Indian Ocean are inter-related. When the surface pressure is high in the sub-tropical region of the Pacific Ocean, in the Northern Hemisphere, the pressure over the southern part of the Indian Ocean tends to be low and vice- versa.

This results in shifting of winds across the Equator. The south-eastern trade winds of the Southern Hemisphere are attracted towards the low pressure of Northern Tropics. These winds often crossing the Equator become south-western monsoons. This is called southern oscillation.

Question 5.
Distinguish between Wind and Jet Streams. Answer:Differences between Wind and Jet Streams are:

Wind	Streams
1. Winds are moving air from high pres¬sure to low pressure areas.	1. Jet streams are fast moving mass of air in the upper troposphere.
2. They move horizontally on the surface of the earth.	2. They move horizontally in the troposphere.
3. Their speed is upto 75 km per hour.	3. Their speed exceeds 200km/hour.
4. Winds are divided as dry winds, moist winds, cold winds and hot winds.	4. Jet streams are divided into western and eastern jet streams.

Question 6.
What is EL Nino? Mention two features of this.
Answer:
EL Nino: The periodic development of warm ocean current along the coast of Peru as a temporary replacement of the cold peruvian current is called EL-Nino. Features of EL-Nino:

1. The presence of the EL-Nino leads to an increase in sea surface temperatures.
2. It weakens the trade winds in the regions and causes heavy rainfall, floods or droughts in different regions of the world.

Question 7.
What is monsoon? Name the two branches of monsoon and briefly explain any one.
Answer:
Monsoon:
it refers to the seasonal reversal in the wind direction during a year. Bay of Bengal Branch.
(a) This branch of monsoon moves along the Bay of Bengal. It advances rapidly and arrives in the North-Eastern part of the country in first week of june.

(b) The lofty mountains cause this branch of monsoon winds to deflect towards the west over the Ganga plain.

(c) It merges with the Arabian Sea branch over the North-Western part of the Ganga plains.

Question 8.
Differentiate between cold weather season and hot weather season of India.
Answer:
Differences between cold and hot weather season are:

Cold Weather Season	Hot Weather Season
1. It begins from mid November in northern India and stays till February.	1. It begins from March and stays till May.
2. The temperature decreases from South to North.	2. Experiences rising temperature and falling air pressure in North India.
3. Days are warm and nights are cold.	3. Hot and dry winds called ‘loo’ blow during the day.
Cold Weather Season	Hot Weather Season

Question 9.
Describe the features of the hot weather season.
Answer:
The main features of the hot weather season are as given under:

1. It lasts from March to May.
2. Intense low pressure develops over the north-western part of India at the end of this season.
3. High temperature around 48°C prevails in this season.
4. Hot dry winds, i.e., Loo blow in the afternoon. They may continue even up to midnight.
5. Dust stroms are common during May in Punjab, Haryana, eastern Rajasthan and western Uttar Pradesh.
6. Local storms of great intensity are also common. These local storms are associated with violent winds, torrential rains and even hailstorms, e.g., Kaal Bai- sakhi in West Bengal and Assam.

Question 10.
Define Kaal Baisakhi, Loo and Mango Showers.
Answer:

1. Kaal Baisakhi: These are the local thunderstorms associated with violent winds, torrential downpours, often accompanied by hail. They occur in West Bengal.
2. Loo: These are stormy, hot, dry winds blowing during the day over the North and North-Western India.
3. Mango Showers: The pre-monsoon showers which help in the ripening of mangoes in coastal Kerala and Karanataka are known as Mango Showers.

Question 11.
Why do Western Ghats receive more rainfall than Eastern Ghats?
Answer:
Western Ghats receive more rainfall than Eastern Ghats because Western Ghats receive rainfall from the Arabian Sea monsoon winds. They does not allow these winds to cross over without shedding their moisture on the western slopes. A part of these winds that reaches the Eastern Ghats is almost dry.

Question 12.
Describe the features of the Advancing Monsoon season.
Answer:
Advancing monsoon season is also known as the hot wet weather season or rainy season.
The features of the Advancing Monsoon season are:

1. It lasts from June to September.
2. 75% to 90% of the total annual rainfall is concentrated over this period.
3. Distribution of rainfall is very largely governed by the relief.
4. The monsoon rains occur in wet spells.
5. The wet spells are interspersed with rainless dry spells.
6. The alternation of dry and wet spells keeps on varying in intensity, frequency and duration.

Question 13.
Where is Mawsynram located? Why does it receive the highest amount of rainfall?
Answer:
Mawsynram is located in the Southern ranges of the Khasi hills in Meghalaya at a height of 1500 metre above the sea level. It receives the highest (annual 1140 cm) rainfall in the world. Mawsynram receives the highest amount of rainfall because:

1. This place is enclosed by hills on three sides.
2. The relief features give this place tunnel-shaped location.
3. The Bay of Bengal monsoon is trapped in these hills. These winds try to get out of there, but are forced to cause heavy rainfall there.

III. Long Answer Type Questions

Question 1.
What are the major controls of the climate of any place? Explain.
Answer:
There are six major controls of the climate of any place. They are:
1. Latitude:
Due to the curvature of the earth, the amount of solar energy received varies according to latitude. As a result, air temperature generally decreases from the equator towards the poles.

2. Altitude:
As one goes from the surface of the earth to higher altitudes, the atmosphere becomes less dense and temperature decreases. The hills are therefore cooler during summers.

3. Pressure and wind system:
The pressure and wind system of any area depend on the latitude and altitude of the place. Thus, it influences the temperature and rainfall pattern.

4. Distance from the sea:
The sea exerts a moderating influence on climate. As the distance from the sea increases, its moderating influence decreases and the people experience extreme weather conditions.

5. Ocean currents:
Ocean currents along with onshore winds affect the climate of the coastal areas. For example, any coastal area with warm or cold currents flowing past it, will be warmed or cooled if the winds are onshore.

6. Relief:
Relief play a major role in determining the climate of a place. High mountains act a barriers for cold or hot winds. They, may also cause precipitation if they are high enough and lie in the path of rain-bearing winds. The leeward side of mountain remains relatively dry.

Question 2.
How is the climate of India governed by the atmospheric conditions?
Answer:
The climate of India is governed by the following atmospheric conditions:
1. Pressure and surface winds:
The surface winds below from region of high pressure to the region of low pressure. During winter, the high pressure area lies in the north of the Himalayas. Over the ocean in the south, there is low pressure, so, wind blow from land toward sthe sea. The reverse occurs during summer.

2. Upper air circulation:
The north-easterly winds originate in sub-tropical high pres-sure belt of northern hemisphere. They blow southwards and get deflected towards right (due to coriolis force) over the low-pressure area of the Indian sub-continent. They are dry and cold and cause no rainfall. Sub-tropical westerly jet stream brings western cyclonic disturbances in north and north-western India during winter.

3. Western cyclonic disturbances and tropical cyclones:
They are a part of easterly flow. They cause heavy to very low rainfall in Eastern coast of India during the monsoon as well as in October-November.

Question 3.
Describe the main characteristics of Retreating Monsoon.
Answer:
Main Characteristics of Retreating Monsoon : Main characteristics of retreating Monsoon are the following:

1. October and November are the months of retreating monsoon.
2. During this time, low monsoon trough becomes weak and is replaced by high pressure. Thus, monsoon begins to retreat. By the beginning of October, it retreats completely from the Northern Plains.
3. This period is the period of transition from hot rainy season to cold winter season. It is marked by clear sky, moist ground and high temperatures giving birth to October heat.
4. Low pressure trough shifts to the Bay of Bengal. They give rise to cyclonic depressions which cause havoc on the eastern coasts, especially the coasts of Odisha, Andhra Pradesh and Tamil Nadu, with very strong storms and rains. The super cyclone of 1999 will remain in the memories of millions of people forever, who lost their near and dear ones alongwith their property.

Question 4
Differentiate between South-west Monsoon and North-east Monsoon.
Answer:
Difference between South-west Monsoon and North-east Monsoon:

South-west Monsoon	North-east Monsoon
1.The winds blowing from South-west to North-east direction during the months of June to September are called South west Monsoon winds.	1. The winds blowing in India from North-east to South-west direction during the months of December to February are called North-east Monsoon winds.
2. These winds blow from South-west towards low pressure region.	2. These winds blow from the high pressure region towards the seas.
3. They are moisture-laden and hot.	3. They are dry and cold.
4. These winds cause 75 to 90% of the total annual rainfall during the reason of south-west monsoon.	4. They cause rainfall on the Tamil Nadu coast during winter.
5. The South-west Monsoon has two branch the Arabian Sea branch and I the Bay of Bengal branch.	5. They do not have branches.
6. Rainy days, soothing winds and overcast sky are the characteristic features of’ the South-west Monsoon.	6. Clear sky, low temperature, gentle breeze and rainless fine weather are the major features of the North-east Monsoon.

Locate & Labelling Meteorological stations cities to locate: Thiruvananthapuram, Chennai, Jodhpur, Bangalore, Mumbai, Kolkata, Leh, Shillong, Delhi, Nagpur.
Answer:

JAC Class 9 Social Science Important Questions

Jharkhand Board JAC Class 10 Maths Solutions Chapter 9 Some Applications of Trigonometry Ex 9.1 Textbook Exercise Questions and Answers.

JAC Board Class 10 Maths Solutions Chapter 9 Some Applications of Trigonometry Exercise 9.1

Question 1.
A circus artist is climbing a 20 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. Find the height of the pole, if the angle made by the rope with the ground level is 30°.
Solution :

sin \(\hat{\mathrm{C}}\) = \(\frac{AB}{AC}\)
sin 30° = \(\frac{1}{2}\)
\(\frac{1}{2}\) = \(\frac{AB}{20}\)
AB = \(\frac{20}{2}\) = 10 m

Question 2.
A tree breaks due to storm and the broken part bends so that the top of the tree touches the ground making an angle 30° with it. The distance between the foot of the tree to the point where the top touches the ground is 8 m. Find the height of the tree.
Solution :

Question 3.
A contractor plans to install two slides for the children to play in a park. For the children below the age of 5 years, she prefers to have a slide whose top is at a height of 1.5 m, and is inclined at an angle of 30° to the ground, whereas for elder children, she wants to have a steep slide at a height of 3m, and inclined at an angle of 60° to the ground. What should be the length of the slide in each case?
Solution:

(i) Figure (a) shows the slide for children below the age of 5 years.
Let BC = 1.5 m be the height of the slide. Slide AC is inclined at CAB = 30° to the ground.
In right angled ΔABC, sin 30° = \(\frac{BC}{AC}\)
\(\frac{1}{2}=\frac{15}{AC}\)
⇒ AC = 3 m.

(ii) Figure (b) shows the slide for elder children. Let RQ = 3 m be the height of the slide. Slide PR is inclined at ∠RPQ = 60° to the ground.
In right angled ΔPQR, sin 60° = \(\frac{RQ}{PR}\) ⇒ \(\frac{\sqrt{3}}{2}\) = \(\frac{3}{PR}\)
PR = \(\frac{3 \times 2}{\sqrt{3}}\) = 2\(\sqrt{3}\) m.

Question 4.
The angle of elevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower, is 30°. Find the height of the tower.
Solution :

tan C = \(\frac{AB}{CB}\)
tan 30° = \(\frac{1}{\sqrt{3}}\)
tan 30° = \(\frac{h}{30}\)
\(\frac{1}{\sqrt{3}}\) = \(\frac{h}{30}\)
h\(\sqrt{3}\) = 30
h = \(\frac{30}{\sqrt{3}}=\frac{30 \times \sqrt{3}}{\sqrt{3} \times \sqrt{3}}=\frac{30 \sqrt{3}}{3}\)
h = 10\(\sqrt{3}\)mts.
Hence, height of the tower is 10\(\sqrt{3}\) mts.

Question 5.
A kite is flying at a height of 60 m above the ground. The string attached to the kite is temporarily tied to a point on the ground. The inclination of the string with the ground is 60°. Find the length of the string, assuming that there is no slack in the string.
Solution :

Length of the string is 40\(\sqrt{3}\) mts.

Question 6.
A 1.5 m tall boy is standing at some distance from a 30 m tall building. The angle of elevation from his eyes to the top of the building increases from 30° to 60° as he walks towards the building. Find the distance he walked towards the building.
Solution :

Let the boy be standing at point B initially. He walks towards the building and reaches point D. From the figure, the distance walked by the boy towards the building is BD.
AC = AG – CG
AC = 30 – 1.5 = 28.5
Now, in ΔABC, we have
tan 30 = \(\frac{AC}{BC}\)
BC = \(\frac{AC}{tan 30}\)
BC = 28.5\(\sqrt{3}\)
Again, in ΔADC, we have
tan 60 = \(\frac{AC}{DC}\)
DC = \(\frac{AC}{tan 60}\)
DC = \(\frac{28.5}{\sqrt{3}}\)
DC = \(\frac{28.5 \sqrt{3}}{3}\) = 9.5\(\sqrt{3}\)
BD = BC – DC
BD = 28.5\(\sqrt{3}\) – 9.5\(\sqrt{3}\)
BD = 19\(\sqrt{3}\)
The distance walked by the boy towards the building is 19\(\sqrt{3}\) m.

Question 7.
From a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high building are 45° and 60° respectively. Find the height of the tower.
Solution :

tan 60° = \(\sqrt{3}\)
tan 45° = 1
In ΔADC, A\(\hat{\mathrm{D}}\)C = 60
tan 60° = \(\frac{AC}{AD}\)
\(\sqrt{3}\) = \(\frac{x+20}{DA}\)

In ΔBDA, A\(\hat{\mathrm{D}}\)B = 45°
tan 45° = \(\frac{AB}{AD}\) = 1
AB = AD = 20 mts.
DA\(\sqrt{3}\) = x + 20
\(\sqrt{3}\)DA = x + 20
\(\sqrt{3}\)(20) = x + 20
x = 20\(\sqrt{3}\) – 20
= 20(\(\sqrt{3}\) – 1)
Height of the tower B = 20(\(\sqrt{3}\) – 1) mts.

Question 8.
A statue, 1.6 m tall, stands on the top of a pedestal. From a point on the ground, the angle of elevation of the top of the statue is 60° and from the same point the angle of elevation of the top of the pedestal is 45°. Find the height of the pedestal.
Solution :

tan 60° = \(\sqrt{3}\)
In ΔADC, tan 60° = \(\frac{AC}{CD}\)
\(\sqrt{3}\) = \(\frac{AC}{CD}\)
AC = \(\sqrt{3}\)CD

In ΔBDC, tan B\(\hat{\mathrm{D}}\)C = tan 45° = \(\frac{BC}{CD}\)
1 = \(\frac{BC}{CD}\)
CD = BC.

A = AC – CB
= AC – CD (∵ CB = CD)
= \(\sqrt{3}\)CD – CD
1.6 = CD(\(\sqrt{3}\) – 1)

Height of the pedestal = 0.8(\(\sqrt{3}\) + 1) mts.

Question 9.
The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.
Solution :

Let the height of the building CD be h.
tan 60° = \(\sqrt{3}\)
tan 30° = \(\frac{1}{\sqrt{3}}\)
In ΔABC, tan \(\hat{\mathrm{C}}\) = \(\frac{AB}{AC}\)
tan 60° = \(\frac{50}{AC}\)
\(\sqrt{3}\) = \(\frac{50}{AC}\)
AC\(\sqrt{3}\) = 50°
AC = \(\frac{50}{\sqrt{3}}\)mts.

Height of the building = 16\(\frac{2}{3}\) mts.

Question 10.
Two poles of equal heights are standing opposite each other on either side of the road, which is 80 m wide. From a point between them on the road, the angles of elevation of the top of the poles are 60° and 30°, respectively. Find the height of the poles and the distances of the point from the poles.
Solution :

Let AE = x.
EB = 80 – x
tan 60° = \(\sqrt{3}\)
tan 30° = \(\frac{1}{\sqrt{3}}\)

Question 11.
A TV tower stands vertically on the bank of a canal. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is 60°. From another point 20 m away from this point on the line joining this point to the foot of the tower, the angle of elevation of the top of the tower is 30°. Find the height of the tower and the width of the canal.
Solution :

tan 60° = \(\sqrt{3}\)
tan 30° = \(\frac{1}{\sqrt{3}}\)
In ΔABC, tan 60° = \(\frac{AB}{BC}\) = \(\frac{h}{x}\)
\(\frac{h}{x}\) = \(\sqrt{3}\)
∴ h = \(\sqrt{3}\)x
In ΔADB, tan 30° = \(\frac{AB}{DB}\)

Height = x\(\sqrt{3}\) = 10\(\sqrt{3}\) mts. Width of the canal = 10 mts.

Question 12.
From the top of a 7 m high building, the angle of elevation of the top of a cable tower is 60° and the angle of depression of its foot is 45°. Determine the height of the tower.
Solution :

In ΔDBC, tan 60° = \(\frac{DC}{BC}\)
\(\sqrt{3}\) = \(\frac{DC}{BC}\)
= \(\frac{DC}{AE}\) = \(\frac{DC}{7}\) (BC = AE).

In ΔABE, tan 45° = \(\frac{AB}{AE}\)
1 = \(\frac{7}{AE}\)
∴ AE = 7 mts.
AB = BC = 7 mts.
DC = 7\(\sqrt{3}\)
∴ DE = DC + CE
= 7\(\sqrt{3}\) + 7 = 7(\(\sqrt{3}\) + 1) mts.

Question 13.
As observed from the top of a 75 m high lighthouse from the sea-level, the angles of depression of two ships are 30° and 45°. If one ship is exactly behind the other on the same side of the lighthouse, find the distance between the two ships.
Solution :

Hence, the distance between the two ships is 75(\(\sqrt{3}\) – 1) m.

Question 14.
A 1.2 m tall girl spots a balloon moving with the wind in a horizontal line at a height of 88.2 m from the ground. The angle of elevation of the balloon from the eyes of the girl at any instant is 60°. After some time, the angle of elevation reduces to 30°. Find the distance travelled by the balloon during the interval.

Solution :

Let the initial position of the balloon be A and final position be B.
Height of the balloon above the girl’s height = 88.2 m – 1.2 m = 87m
Distance travelled by the balloon = DE = CE – CD

Distance travelled by the balloon, DE = CE – CD
= (87\(\sqrt{3}\) – 29\(\sqrt{3}\)) m
= 29\(\sqrt{3}\) (3 – 1) m
= 58\(\sqrt{3}\) m.

Question 15.
A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of 30°, which is approaching the foot of the tower with a uniform speed. Six seconds later, the angle of depression of the car is found to be 60°. Find the time taken by the car to reach the foot of the tower from this point.
Solution :

In ΔBCA, tan 30° = \(\frac{h}{CA}\)
\(\frac{1}{\sqrt{3}}\) = \(\frac{h}{CA}\)
CA = h\(\sqrt{3}\) mts.

Question 16.
The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary. Prove that the height of the tower is 6 m.
Solution :

Let AB be the tower. ∠ABC = x
∴ ∠ADB = 90° – x
In ΔABC tan x = \(\frac{AB}{BC}\)
tan x = \(\frac{AB}{4}\) ……………(i)
In ΔADB tan (90° – x) = \(\frac{AB}{9}\)
cot x = \(\frac{AB}{9}\) ……………(ii)
(i) × (ii)
tan x × cot x = \(\frac{AB}{4}\) × \(\frac{AB}{9}\)
tan x × \(\frac{1}{tan x}\) = \(\frac{\mathrm{AB}^2}{36}\)
1 = \(\frac{\mathrm{AB}^2}{36}\)
AB² = 36
AB = ± \(\sqrt{36}\)
AB = ± 6
∴ Height of the tower AB = 6 m.
Note: C and D can be taken on the same side of AB.

JAC Board Class 9th Social Science Notes Geography Chapter 2 Physical Features of India

→ Introduction

• India has practically all the physical features of the Earth like mountains, plains, deserts, plateaus, islands etc.
• Geologically, the land of India displays great physical variation.

→ Major Physiographic Divisions

• The physical features of India can be grouped under the following physiographic divisions: (i) The Himalayan mountains, (ii) The Northern plains, (iii) The Peninsular plateau, (iv) The Indian desert, (v) The Coastal plains, (vi) The Islands.

→ The Himalayan Mountains

• The Himalayan mountains are the major sources of water and forest wealth.
• The Himalayas are geologically young and structurally fold mountains. They stretch over the Northern borders of India.
• The Himalayas consists of three parallel ranges in its longitudinal extent: (i) The Great or Inner Himalayas or the ‘Himadri’, (ii) The Middle or lesser Himalayas or The ‘Himachal’ (iii) The Outer Himalayas or The ‘Shiwaliks’.
• The Himalayas are also divided on the basis of regions from West to East. This demarcation is done by river valleys, i.e. the Indus, Sutlej, Kali, Teesta and Dihang rivers.
• In the west, the part of Himalayas lying between Indus and Sutlej has been traditionally known as Punjab Himalayas.
• The part of Himalayas lying between Sutlej and Kali rivers is known as Kumaon Himalayas.
• The Kali and Teesta rivers demacrate the Nepal Himalayas and the part lying between Teesta and Dihang rivers is known as Assam Himalayas.
• Purvanchal or the Eastern hills and mountains running through the North-Eastern states are mostly composed of strong sand stones, which are sedimentary rocks covered with dense forest.

→ The Northern Plains

• The Northern plains are the granaries of the country. They provided the base for early civilisations.
• The Northern Plain has been formed by the interplay of the three major river systems, namely the Indus, the Ganga and the Brahmaputra along with their tributaries.
• The Northern plain is broadly divided into three sections: (i) The Punjab plains, (ii) The Ganga plains, (iii) The Brahmaputra plains.
• According to the variations in relief features, the northern plains can be divided into four regions:(i) Bhabar, (ii) Terai, (iii) Bangar, (iv) Khadar.
• The largest part of the Northern plain is formed of older alluvium.

→ The Pfehinsular Plateau

• The Peninsular Plateau is a tableland composed of the old crystalline, igneous and metamorphic rocks. This plateau consists of two broad divisions, namely, the Central Highlands, the Deccan Plateau.
• The Western Ghats and the Eastern Ghats mark the western and the eastern edges of the Deccan Plateau respectively.
• The Western part of the plateau, known as the Deccan Trap, contains black soil of volcanic origin.

→ The Indian Desert

• The Indian Desert lies towards the western sides of the Aravalli Hills. It is an undulating sandy plain covered with sand dunes.
• Luni is the only large river in this region.
• This region receives very low rainfall, i.e. below 150 mm per year.

→ The Coastal Plains

• The Peninsular Plateau is boardered by stretches of narrow coastal strips, running along the Arabian Sea on the West and the Bay of Bengal on the east.
• The Western coast consists of three sections (i) The Konkan Coast, (ii) The Kannad Plain (iii)The Malabar Coast.
• The Eastern Coast consists of the Northern Circar and the Coromandel Coast.

→ The Islands

• The Lakshadweep islands group lies close to the Malabar coast of Kerala and are composed of small coral islands.
• The elongated chain of the Andaman and Nicobar islands located in the Bay of Bengal extends from North to  South.

→ Mountain: A mountain is a large landform that rises above the surrounding land in a limited area, usually in the form of a peak.

→ Desert: A large dry area, largely devoid of vegetation for want of rain or water.

→ Plateau: A wide, flat, topped area, rising abruptly from the surrounding low-lying area or a water body.

→ Island: A piece of land that is completely surrounded by sea, a river or lake.

→ Valley: A valley is a low area between hills or mountains typically with a river running through it.

→ Ox-bow lake: A crescent-shaped lake on a river floodplain.

→ Fold Mountains: An upland area, such as the Himalayas or Alps formed by the buckling of the Earth’s crust.

→ Physiography: Shape and relief or geographical features of an area.

→ Glacier: A glacier is a huge mass of ice that moves slowly over land.

→ Tributaries: Streams or small rivers that flow into a larger river.

→ Distributary: A river that originates from a major river. It is formed near the river’s mouth before falling into the sea.

→ Waterfall: A waterfall is an area where water flows over a vertical drop or a series of steep drops in the course of a stream or river.

→ Riverine Islands: Islands on a river.

→ Gondwana land: It was an ancient super-continent located in Southern Hemisphere which included the present-day South America, Africa, Australia snd Antarctica.

→ Bhangar: The older alluvium of the Northern Plain is called the Bhangar.

→ Khadar: The younger alluvium of the floodplains is known as the Khadar.

→ Duns: Narrow valleys found between Shiwaliks and Middle Himalayas.

→ Strait: A narrow stretch of water joining two oceans or large water bodies.

→ Barchans: Barchan also spelled Barkhan, crescent-shaped sand dunes produced by the action of wind an predominantly from one direction.

→ Tectonic Plates: Due to internal heat of the Earth, the currents of the semi-molten rocks move towards the crust, and tear it apart, dividing it into large fragments which are called Tectonic Plates.

→ Tethys: An elongated shallow sea sandwiched between two ancient landmasses.

→ Coral: Coral polyps are short-lived microscopic organisms which live in colonies. They flourish in shallow, mud free and warm waters. They secrete calcium carbonate.

→ Atolls: These are circular or horse-shoe-shaped coral reefs. Lakshadweep is one such type.

→ Gorge: The steep-sided narrow and deep valley of a river formed in its upper course is termed as a gorge. It is also called an I-shaped valley.

JAC Class 9 Social Science Notes