Class 10 Science - Chapter 2: Control and
Coordination
Detailed Colorful CBSE Notes
1. Introduction
Control and Coordination is the process by which living organisms regulate body activities and
respond to changes in their surroundings. It helps organisms survive and maintain balance in the
body.
2. Coordination in Animals
Animals coordinate their activities through the nervous system and endocrine system. The nervous
system provides quick responses while hormones provide slower but long-lasting responses.
3. Nervous System
The nervous system controls and coordinates all body activities.
Main Parts:
• Brain
• Spinal Cord
• Nerves
Neuron:
Neuron is the structural and functional unit of the nervous system.
Parts of Neuron:
• Dendrites
• Cell Body
• Axon
Functions:
• Receive impulses
• Transmit impulses
• Help communication within the body 4. Reflex Action
Reflex action is a quick and automatic response to a stimulus.
Examples:
• Pulling hand away from a hot object
• Blinking of eyes
Reflex Arc:
Receptor → Sensory Neuron → Spinal Cord → Motor Neuron → Effector
Importance:
• Provides quick protection
• Prevents injury
5. Human Brain
The brain is the control center of the body.
Forebrain:
• Thinking
• Memory
• Intelligence
• Voluntary actions
Midbrain:
• Visual and auditory reflexes
Hindbrain:
• Balance
• Posture
• Breathing
• Heartbeat
Protection of Brain:
• Skull
• Cerebrospinal Fluid
6. Coordination in Plants
Plants do not have nerves but show movements due to stimuli.
Plant Movements:
• Tropic Movements
• Nastic Movements
Tropic Movements:
Growth movements in response to stimuli.
Types:
1. Phototropism – response to light
2. Geotropism – response to gravity
3. Hydrotropism – response to water
4. Thigmotropism – response to touch
5. Chemotropism – response to chemicals 7. Plant Hormones
Plant hormones control growth and development.
Auxins:
• Promote growth
• Responsible for phototropism
Gibberellins:
• Increase stem growth
Cytokinins:
• Promote cell division
Abscisic Acid:
• Inhibits growth
• Causes dormancy
8. Endocrine System
The endocrine system consists of glands that secrete hormones.
Hormones are chemical messengers that regulate body functions.
Major Endocrine Glands:
• Pituitary Gland
• Thyroid Gland
• Adrenal Gland
• Pancreas
• Testes
• Ovaries
9. Important Human Hormones
Pituitary Hormone:
• Controls growth
Thyroxine:
• Regulates metabolism
• Requires iodine
Adrenaline:
• Emergency hormone
• Prepares body for stress
Insulin:
• Controls blood sugar level
Testosterone:
• Male sex hormone
Estrogen:
• Female sex hormone
10. Feedback Mechanism The body maintains hormone levels through feedback mechanisms.
Example:
When thyroxine level increases, the pituitary gland reduces TSH secretion. This helps maintain
balance in the body. 11. Differences to Remember
Nervous System vs Endocrine System
Nervous System:
• Fast response
• Electrical impulses
• Short duration
Endocrine System:
• Slow response
• Hormones
• Long duration
Tropic Movement vs Nastic Movement
Tropic:
• Direction dependent
• Growth movement
Nastic:
• Direction independent
• Non-growth movement
12. NCERT Important Questions
1. What is a reflex action?
2. Draw and explain reflex arc.
3. What are the functions of the forebrain?
4. Explain phototropism.
5. Name four plant hormones.
6. What is the role of thyroxine?
7. Why is iodine necessary?
8. Differentiate between nervous and endocrine systems.
9. What is coordination?
10. Explain feedback mechanism.
13. Quick Revision Sheet
• Neuron is the functional unit of the nervous system.
• Brain is protected by skull and cerebrospinal fluid.
• Reflex actions are controlled by spinal cord.
• Auxin helps plant growth.
• Adrenaline is the emergency hormone.
• Insulin controls blood sugar.
• Thyroxine regulates metabolism.
• Phototropism is movement towards light.
• Hydrotropism is movement towards water.
• Endocrine glands secrete hormones.