CBSE Class 10 Science Notes

Chapter 7: Control and Coordination

1. Control and Coordination in Animals

• Nervous System: Includes the brain, spinal cord, and nerves.
  
  • Brain Parts:
    
    • Cerebrum: Controls voluntary actions, reasoning, and memory.
    • Cerebellum: Maintains posture and balance.
    • Medulla: Manages involuntary actions like breathing.
• Reflex Action: Rapid, automatic response to stimuli via reflex arc.
• Hormones: Chemical messengers (e.g., insulin, adrenaline).

2. Control and Coordination in Plants

• Plant Hormones:
  
  • Auxins: Promote stem elongation.
  • Cytokinins: Stimulate cell division.
  • Gibberellins: Help in seed germination.
  • Abscisic Acid: Inhibits growth.
• Tropic movements (e.g., phototropism, geotropism).

3. Endocrine System in Humans

• Key glands:
  
  • Pituitary: Growth hormone.
  • Thyroid: Thyroxine for metabolism.
  • Pancreas: Insulin regulates blood sugar.
  • Adrenal: Adrenaline for stress response.

These systems ensure efficient coordination in living organisms.

Most Important Science Class 10 Questions Answers For Board Examination

Top Questions and Answers from Chapter 7: Control and Coordination

1. Question: What is the difference between reflex action and voluntary action?
   Answer:

   • Reflex Action: Involuntary and immediate response to stimuli (e.g., withdrawing a hand from a hot surface). Controlled by the spinal cord.
   • Voluntary Action: Conscious control (e.g., picking up an object). Managed by the brain.

2. Question: Explain the role of plant hormones.
   Answer:

   • Auxins: Promote cell elongation and bending toward light (phototropism).
   • Cytokinins: Stimulate cell division.
   • Gibberellins: Aid in seed germination and stem growth.
   • Abscisic Acid: Inhibits growth, and induces dormancy.

3. Question: How does the human brain protect itself?
   Answer: The brain is protected by:

   • Cranium: A bony structure.
   • Meninges: Three protective membranes.
   • Cerebrospinal Fluid: Cushions against shocks.

4. Question: Why is adrenaline called the “emergency hormone”?
   Answer: Adrenaline prepares the body for “fight or flight” by increasing heart rate, dilating pupils, and directing blood to muscles during stress or emergencies.

Most Important MCQs Science Class 10 For Board Examination

MCQs in Chapter 7: Control and Coordination

1. Which part of the brain controls involuntary actions like breathing and heartbeat?
   a) Cerebrum
   b) Medulla
   c) Cerebellum
   d) Hypothalamus
   Answer: b) Medulla

2. Which plant hormone is responsible for cell elongation and phototropism?
   a) Cytokinin
   b) Abscisic Acid
   c) Auxin
   d) Gibberellin
   Answer: c) Auxin

3. What is the main function of the cerebellum?
   a) Memory storage
   b) Coordination of body movements
   c) Regulation of hormones
   d) Reflex actions
   Answer: b) Coordination of body movements

4. Which hormone is secreted in response to stress and prepares the body for emergency action?
   a) Insulin
   b) Adrenaline
   c) Thyroxine
   d) Estrogen
   Answer: b) Adrenaline

5. What is the direction of flow of information in a reflex action?
   a) Receptor → Brain → Effector
   b) Effector → Spinal Cord → Brain
   c) Receptor → Spinal Cord → Effector
   d) Spinal Cord → Receptor → Brain
   Answer: c) Receptor → Spinal Cord → Effector

6. Which of the following plant hormones inhibits growth and promotes dormancy?
   a) Auxin
   b) Cytokinin
   c) Gibberellin
   d) Abscisic Acid
   Answer: d) Abscisic Acid

7. Which type of neuron carries messages from the central nervous system to effectors?
   a) Sensory Neuron
   b) Interneuron
   c) Motor Neuron
   d) None of these
   Answer: c) Motor Neuron

8. Which part of the nervous system is involved in reflex actions?
   a) Brain
   b) Spinal Cord
   c) Cerebrum
   d) Cerebellum
   Answer: b) Spinal Cord

9. The bending of plants toward light is an example of:
   a) Geotropism
   b) Chemotropism
   c) Phototropism
   d) Hydrotropism
   Answer: c) Phototropism

10. What is the role of insulin in the human body?
    a) Controls metabolism rate
    b) Regulates blood sugar levels
    c) Promotes growth and repair
    d) Helps in digestion
    Answer: b) Regulates blood sugar levels