Students must go through these JAC Class 10 Science Notes Chapter 15 Our Environment to get a clear insight into all the important concepts.
JAC Board Class 10 Science Notes Chapter 15 Our Environment
→ Environment: It is the sum total of all external conditions and influences that affect the life and development of an organism, i.e., the environment includes all physical or abiotic and biological factors. All the factors of environment are affecting the organisms.
→ Ecosystem: A system formed by an interaction between biotic environment is components and the physical called an ecosystem.
→ Food chain and food web: Living organisms of an ecosystem depend on each other for their food requirement and form a chain. This is termed as food chain.
- A food chain describes unidirectional flow of energy and cyclic flow of materials in an ecosystem.
- Each ecosystem has its own specific food chain. The individuals involved in one food chain are linked with food chains of other ecosystem and forms a complex net which is termed as a food web.
→ Trophic levels: Each step in the food chain constitutes a trophic level.
- There are generally 3-4 trophic levels in food chain.
- Sun is the energy source for any food chain.
- Producers constitute 1st trophic level in a food chain and they are the entrance for solar energy in an ecosystem.
→ Biological magnification : A progressive increase in the concentration of non- biodegrable substances in organisms at each successive trophic level in known as biological magnification.
→ Ozone layer: Ozone at the higher levels of the atmosphere (stratosphere) is a product of UV radiation acting on oxygen (Oa) molecule.
- Ozone forms shield surrounding the earth that protect against harmful UV radiation from the sun.
→ Ozone depletion : An event of dropping sharply in the amount of ozone in the atmosphere is known as ozone depletion.
- CFCs – Chlorofluorocarbons used in refrige-rators and air-conditioners is responsible for ozone depletion.
→ Waste: Unwanted, unusable items, remains and other products of household garbage are called waste.
The disposal of the waste generated by us is causing serious environmental problems.
→ Household waste management: Each person in urban areas produces 500grams of garbage everyday.
- Such wastes can be a source of extra income when properly managed. Use of reusable and rechargeable items, proper disposal of wastes and prevents the use of plastic, polythene.