Students must go through these JAC Class 10 Science Notes Chapter 7 Control and Coordination to get a clear insight into all the important concepts.
JAC Board Class 10 Science Notes Chapter 7 Control and Coordination
→ The movement is shown as a response to a change in the environment by the organism.
→ Each kind of a change in the environment evokes an appropriate movement as a response.
→ Some movements are growth related while others are not.
→ Nervous system and hormones bring about control and coordination of the bodies.
→ Neuron is a structural and functional unit of nervous tissue.
→ Cell body (cyton), dendrites and axon are the structural parts of neuron.
→ The responses of the nervous system can be classified as reflex action, voluntary action and involuntary action.
→ Reflex action is an involuntary response to external stimuli without the knowledge of voluntary centres of brain.
→ Reflex arc is a connection between the input (sensory) nerve and the output (motor) nerve along with spinal cord.
→ Voluntary actions occur under the control of will of an animal.
→ The nervous system uses electrical impulses to transmit messages.
→ Human nervous system :
- Central nervous system is made-up of brain and spinal cord.
- Peripheral nervous system is made-up of cranial nerves and spinal nerves.
Brain has three major parts:
- Fore-brain
- mid-brain and
- hind-brain.
→ Brain is protected in bony box and spinal cord is protected in a vertebral column.
→ The simplest form of movement at the cellular level is the movement of muscle cell.
→ Plants have neither a nervous system nor muscles.
→ Plants show two different types of movements – one dependent on growth and other independent of growth.
→ Touch-me-not is a plant of the Mimosa family whose leaves move very quickly in response to touch.
→ Tendrils of a pea plant are sensitive to touch.
→ Environmental factors such as light, gravity, water, etc. change the directions of growing part of a plant. These are called directional or tropic movements.
→ Chemical coordination is seen in both plants and animals.
→ Auxin, gibberellin and cytokinin are growth promoting hormones of plants. Abscisic acid is a plant hormone which inhibits growth.
→ In animals the chemical coordination is due to neurotransmitters and hormones.
→ An endocrine gland is the ductless gland that secretes hormones.
→ Hormones are directly poured into blood and are transported to their functional site.
→ Pituitary gland, pineal gland, thyroid gland, parathyroid gland, thymus gland, adrenal gland, pancreas and testis or ovary are endocrine glands in human body.
→ The timing and amount of hormone secretion are regulated by feedback mechanisms.