THE BUSY BRAINS • BY MANSI SARASWAT
CONTROL AND COORDINATION
Class 10 Science | Important Questions with Answers
Pre-Board & Board Exam Preparation
| NCERT-Based Questions | Biology | Diagrams | MCQs | Case-Based Questions
Class 10 Science – Control and Coordination is an important Biology chapter for CBSE Board Exam and Pre-Board preparation. This chapter explains how living organisms detect changes in their surroundings and produce appropriate responses through systems of control and coordination.
This comprehensive Class 10 Control and Coordination Important Questions with Answers resource covers the nervous system, receptors, neuron, electrical impulses, synapse, reflex action, reflex arc, spinal cord, human brain, voluntary and involuntary actions.
The chapter also covers coordination in plants, sensitive plant movement, phototropism, geotropism, hydrotropism, chemotropism, auxin, gibberellins, cytokinins and abscisic acid. Students must also revise animal hormones, endocrine glands, adrenaline, thyroxine, growth hormone, insulin, testosterone and oestrogen.
This post is designed for CBSE Class 10 Science Board Exam preparation and includes important questions, NCERT exercise-based questions, diagrams, MCQs, case-based questions, comparison tables, quick revision and exam strategy.
MUST DO
Neuron, Reflex Arc, Human Brain, Plant Hormones & Animal Hormones
VERY IMPORTANT
Receptors, Synapse, Tropisms, Endocrine Glands & Hormone Functions
PRACTICE
Diagrams, NCERT Questions, MCQs, Case-Based Questions & Differences
⭐ Board Exam Focus:
Learn the
structure of neuron, reflex arc, human brain,
endocrine glands and plant tropisms.
Practise diagrams and learn hormone functions in a
clear table format.
1. Control and Coordination
MUST DO
Q1. What is control and coordination?
Answer:
Control and coordination are the processes through which living
organisms recognise changes in their surroundings and produce
appropriate responses.
In multicellular organisms, specialised tissues and systems help
in carrying out these functions.
Q2. Why is a system of control and coordination necessary in organisms?
Living organisms constantly receive information from their
environment.
They need to recognise these changes and respond appropriately.
A system of control and coordination helps different parts of the
body work together and produce suitable responses to stimuli.
Q3. What is a stimulus?
A stimulus is a change in the environment that can
be detected by an organism and can produce a response.
Examples include heat, light, sound, touch and chemicals.
Q4. What are the two major systems of control and coordination in animals?
The two major systems are:
- Nervous system – uses electrical impulses through nerve cells.
- Hormonal system – uses chemical messengers called hormones.
2. Nervous System and Neuron
MUST DO
Q5. What is nervous tissue?
Nervous tissue is specialised for conducting information from one
part of the body to another through electrical impulses.
It is made up of an organised network of nerve cells called
neurons.
VERY IMPORTANT
Q6. What is a neuron?
A neuron is the structural and functional unit of nervous tissue.
It is specialised to receive information and transmit it as
electrical impulses.
Q7. Name the main parts of a neuron.
The main parts of a neuron are:
- Dendrites
- Cell body
- Axon
- Axon terminals
Q8. What is the function of dendrites?
Dendrites receive information or stimuli and initiate the
generation of an electrical impulse.
Q9. What is the function of the axon?
The axon carries the electrical impulse away from the cell body
towards its end.
VERY IMPORTANT
Q10. What is a synapse?
A synapse is the small gap between two neurons.
When an electrical impulse reaches the end of an axon, chemicals
are released.
These chemicals cross the synapse and initiate a similar
electrical impulse in the dendrite of the next neuron.
Q11. How does a nerve impulse travel through a neuron?
The general sequence is:
The impulse is transmitted electrically through the neuron.
At the axon end, chemicals are released across the synapse.
Dendrite
→
Cell Body
→
Axon
→
Axon End
→
Synapse
Q12. What are receptors?
Receptors are specialised structures that detect information
from the environment.
They are usually located in sense organs.
For example:
- Gustatory receptors detect taste.
- Olfactory receptors detect smell.
Q13. What would happen if receptors did not work properly?
If receptors fail to work properly, the organism may not detect
important changes in its environment.
For example, failure of receptors involved in detecting heat or
pain could prevent a person from responding properly to harmful
stimuli.
3. Reflex Action and Reflex Arc
MUST DO
Q14. What is reflex action?
A reflex action is a quick response to a stimulus
that occurs without conscious thinking about the response.
For example, pulling the hand away quickly after touching a hot
object.
VERY IMPORTANT
Q15. What is a reflex arc?
A reflex arc is the pathway through which the
nerve impulse travels during a reflex action.
Reflex arcs are formed in the spinal cord and allow quick
responses to potentially harmful stimuli.
Q16. Explain the pathway of a reflex action when a person touches a hot object.
The sequence can be represented as:
The information also reaches the brain, but the reflex response
can be completed quickly through the spinal cord.
Hot Object
→
Receptor
→
Sensory Neuron
→
Spinal Cord
→
Motor Neuron
→
Muscle
→
Hand Withdraws
Q17. Why are reflex arcs important?
Reflex arcs provide an efficient pathway for quick responses.
They are useful in situations where a rapid response can protect
the body from injury.
Q18. Differentiate between reflex action and walking.
| Reflex Action | Walking |
|---|---|
| Quick response to a stimulus. | A coordinated movement involving voluntary control. |
| Does not require conscious thinking before the response. | Normally involves deciding and coordinating movement. |
| Reflex arcs are involved. | Brain coordination and the nervous system are involved. |
Q19. What is the role of the spinal cord in reflex action?
The spinal cord provides the pathway where reflex arcs are formed.
It allows the body to produce a quick response to a stimulus.
Information from the stimulus also continues towards the brain.
4. Human Brain
MUST DO
Q20. Why is the brain called the main coordinating centre of the body?
The brain receives information from different parts of the body,
integrates it and helps decide appropriate responses.
It also sends instructions to muscles and other parts of the body.
Q21. What constitutes the central nervous system?
The brain and spinal cord together constitute the
central nervous system.
Q22. What is the peripheral nervous system?
The peripheral nervous system consists of nerves that connect
the central nervous system with different parts of the body.
It includes cranial nerves arising from the brain and spinal nerves
arising from the spinal cord.
VERY IMPORTANT
Q23. Name the three major regions of the human brain.
The three major regions are:
- Fore-brain
- Mid-brain
- Hind-brain
Q24. What is the function of the fore-brain?
The fore-brain is the main thinking part of the brain.
It receives sensory information and helps interpret it by combining
information from different receptors and information already stored
in the brain.
It also helps control voluntary actions.
Q25. What is the function of the cerebellum?
The cerebellum is a part of the hind-brain.
It is responsible for the precision of voluntary actions and for
maintaining posture and balance of the body.
Examples include walking in a straight line, riding a bicycle and
picking up a pencil.
Q26. What is the role of the medulla?
The medulla is a part of the hind-brain.
It controls involuntary actions such as
blood pressure, salivation and vomiting.
Q27. Differentiate between voluntary and involuntary actions.
| Voluntary Actions | Involuntary Actions |
|---|---|
| Performed under conscious control. | Do not normally require conscious control. |
| Example: writing or moving a chair. | Example: heartbeat and salivation. |
Q28. How are reflex actions different from involuntary actions?
Both may occur without conscious control, but they are not identical.
A reflex action is a rapid response to a specific
stimulus, often involving a reflex arc.
An involuntary action is an action that occurs without
conscious control, such as heartbeat or salivation.
Q29. How is the brain protected?
The brain is protected by the
bony skull.
It is also enclosed in a fluid-filled structure that provides
additional shock absorption.
The spinal cord is protected by the
vertebral column or backbone.
VERY IMPORTANT
Q30. What would happen if the spinal cord were injured?
Signals travelling between the brain and parts of the body supplied
through the spinal cord may be disrupted.
Depending on the location and severity of injury, communication
between the brain and body parts can be affected.
5. Coordination in Plants
MUST DO
Q31. How do plants respond to stimuli without a nervous system?
Plants do not have a nervous system or muscles.
They can respond to stimuli through
electrical-chemical means and through chemical
signals such as plant hormones.
Plant cells can also change their shape by changing the amount
of water in them.
Q32. How does the sensitive plant respond to touch?
When the leaves of the sensitive plant are touched, they fold up
and droop quickly.
This movement does not depend on growth.
Information is communicated through electrical-chemical means,
and plant cells change shape by changing their water content.
Q33. How is the movement of a sensitive plant different from the movement of a shoot towards light?
The sensitive plant shows a relatively quick movement in response
to touch and this movement does not involve growth.
A shoot bending towards light is a slower movement caused by
growth.
Q34. What are tropic movements?
Tropic movements are directional growth movements of plants in
response to environmental stimuli.
They may occur towards or away from the stimulus.
6. Tropic Movements in Plants
MUST DO
Q35. What is phototropism?
Phototropism is the directional growth movement of a plant part
in response to light.
Shoots generally bend towards light, while roots can grow away
from light.
Q36. How does phototropism occur in plants?
The shoot tip synthesises the plant hormone
auxin.
When light comes from one side, auxin diffuses towards the shaded
side.
Cells on the shaded side grow longer, causing the shoot to bend
towards the light.
VERY IMPORTANT
Q37. What is geotropism?
Geotropism is directional growth in response to gravity.
Roots generally grow downwards towards the pull of gravity, while
shoots generally grow upwards and away from the earth.
Q38. What is hydrotropism?
Hydrotropism is the directional growth of a plant part in response
to water.
Q39. What is chemotropism?
Chemotropism is directional growth in response to chemicals.
An example given in the chapter is the growth of
pollen tubes towards ovules.
Q40. Differentiate between phototropism and geotropism.
| Phototropism | Geotropism |
|---|---|
| Response to light. | Response to gravity. |
| Shoots generally grow towards light. | Roots generally grow downwards. |
PRACTICE
Q41. Design an experiment to demonstrate hydrotropism.
A simple experimental setup can be designed in which a growing
root is provided with a moisture gradient.
The arrangement should ensure that water is available more strongly
on one side.
After sufficient time, observe whether the root bends and grows
towards the region with greater moisture.
The observation can be used to demonstrate directional growth
in response to water.
7. Plant Hormones
MUST DO
Q42. What are plant hormones?
Plant hormones are chemical substances that help coordinate
growth, development and responses to environmental stimuli.
They are synthesised at particular places and can diffuse to
the region where they act.
Q43. Name the important plant hormones discussed in the chapter.
The important plant hormones discussed are:
- Auxins
- Gibberellins
- Cytokinins
- Abscisic acid
Q44. What is the function of auxin?
Auxin promotes cell growth.
In phototropism, auxin produced at the shoot tip moves towards
the shaded side and promotes greater growth there, causing the
shoot to bend towards light.
Q45. What is the function of gibberellins?
Gibberellins help in the
growth of the stem.
Q46. What is the function of cytokinins?
Cytokinins promote
cell division.
They are found in greater concentration in regions of rapid
cell division, such as fruits and seeds.
Q47. What is the function of abscisic acid?
Abscisic acid is a plant hormone that
inhibits growth.
One of its effects is the wilting of leaves.
Q48. Complete the following table of plant hormones.
| Hormone | Main Function |
|---|---|
| Auxin | Promotes cell growth and helps in phototropism. |
| Gibberellins | Promote stem growth. |
| Cytokinins | Promote cell division. |
| Abscisic Acid | Inhibits growth and can cause wilting of leaves. |
8. Hormones in Animals
VERY IMPORTANT
Q49. Why do animals require chemical coordination?
Electrical impulses are useful for rapid communication, but they
have limitations because they reach cells connected by nervous
tissue.
Chemical signals called hormones can be transported through the
blood and can reach target organs and tissues.
Thus hormonal coordination provides another system of control.
Q50. What is a hormone?
A hormone is a chemical messenger produced by specialised glands
or tissues that travels to target organs or tissues and produces
a specific effect.
MUST DO
Q51. What is the role of adrenaline?
Adrenaline is secreted by the
adrenal glands.
During situations such as fear or stress, it is released into the
blood and prepares the body for rapid action.
Its effects include:
- Faster heartbeat.
- Increased breathing rate.
- Greater blood supply to skeletal muscles.
- Reduced blood flow to the digestive system and skin.
Q52. Why is adrenaline called an emergency hormone?
Adrenaline prepares the body for immediate physical activity
during stressful or frightening situations.
It increases heartbeat and breathing and directs more blood towards
skeletal muscles.
Therefore it helps the body prepare for rapid action.
9. Endocrine Glands and Important Hormones
Q53. What are endocrine glands?
Endocrine glands are glands that release hormones into the blood.
The hormones are then transported to their target organs or tissues.
MUST DO
Q54. What is the function of the thyroid gland?
The thyroid gland produces
thyroxine.
Thyroxine regulates carbohydrate, protein and fat metabolism in
the body and is important for proper growth and development.
Q55. Why is iodised salt recommended?
Iodine is necessary for the synthesis of
thyroxine by the thyroid gland.
A deficiency of iodine can lead to
goitre, which may include swelling of the neck.
Therefore, iodised salt helps ensure an adequate supply of iodine.
VERY IMPORTANT
Q56. What is the function of growth hormone?
Growth hormone is secreted by the
pituitary gland.
It regulates growth and development of the body.
Deficiency of growth hormone during childhood can lead to dwarfism.
Q57. What is the function of insulin?
Insulin is produced by the
pancreas.
It helps regulate the level of sugar in the blood.
Q58. Why are some diabetic patients given insulin injections?
Insulin helps regulate blood sugar levels.
If sufficient insulin is not secreted, blood sugar levels can rise
and cause harmful effects.
Insulin may therefore be administered as a treatment in appropriate
cases.
Q59. What are the functions of testosterone and oestrogen?
Testosterone is secreted by the testes and is involved
in changes associated with puberty in males.
Oestrogen is secreted by the ovaries and is involved in
the development of female sex organs and regulation of the
menstrual cycle.
Q60. What is feedback mechanism in hormonal coordination?
A feedback mechanism regulates the timing and amount of hormone
released.
For example, when blood sugar rises, pancreatic cells produce
more insulin.
As blood sugar falls, insulin secretion is reduced.
| Hormone | Endocrine Gland | Main Function |
|---|---|---|
| Growth Hormone | Pituitary | Stimulates growth and development. |
| Thyroxine | Thyroid | Regulates metabolism important for growth. |
| Insulin | Pancreas | Regulates blood sugar level. |
| Testosterone | Testes | Male sexual development and puberty-related changes. |
| Oestrogen | Ovaries | Female sexual development and menstrual cycle. |
| Adrenaline | Adrenal gland | Prepares body for emergency action. |
10. Draw & Label – Important Diagram Questions
⭐ Diagram Focus:
The NCERT exercise directly asks students to
draw the structure of a neuron and explain its function.
The chapter also contains important diagrams of the
reflex arc, human brain, sensitive plant, phototropism,
geotropism and endocrine glands.
DIAGRAM – 1
Q61. Draw a neat and labelled diagram of a neuron.
Important labels:
Dendrites • Cell Body • Nucleus • Axon •
Axon Terminals
⭐ Board Tip: Show the direction of the nerve impulse from dendrite towards the axon terminals.
DIAGRAM – 2
Q62. Draw and label the reflex arc.
Show the pathway:
Receptor → Sensory Neuron → Spinal Cord →
Motor Neuron → Effector Muscle
⭐ Include the stimulus and response clearly.
DIAGRAM – 3
Q63. Draw and label the human brain.
Important labels:
Fore-brain • Mid-brain • Hind-brain •
Cerebellum • Medulla • Spinal Cord
⭐ Learn the function of each major region along with the diagram.
DIAGRAM – 4
Q64. Draw the sensitive plant showing its response to touch.
Show:
Normal leaves → Touch stimulus → Folded / Drooping leaves
DIAGRAM – 5
Q65. Draw a plant showing phototropism.
Important labels:
Light → Shoot tip → Auxin → Shaded side →
Unequal growth → Bending towards light
DIAGRAM – 6
Q66. Draw a plant showing geotropism.
Show:
Roots growing downward → Gravity →
Shoots growing upward
DIAGRAM – 7
Q67. Draw an experimental setup to demonstrate hydrotropism.
Show:
Growing root • Moist region • Dry region →
Root bending towards water
DIAGRAM – 8
Q68. Draw and label the endocrine glands in the human body.
Important glands shown in the chapter:
Pituitary • Thyroid • Adrenal glands •
Pancreas • Testes / Ovaries
⭐ Learn one important hormone and function associated with each gland.
DIAGRAM – 9
Q69. Draw the response of a tendril to touch.
Show:
Tendril → Support → Unequal growth →
Tendril coils around support
DIAGRAM – 10
Q70. Draw a flowchart showing how a stimulus produces a response.
Stimulus
→
Receptor
→
Nervous System
→
Effector
→
Response
🎯 Diagram Revision Checklist
- ☑ Structure of neuron
- ☑ Reflex arc
- ☑ Human brain
- ☑ Sensitive plant response
- ☑ Phototropism
- ☑ Geotropism
- ☑ Hydrotropism experiment
- ☑ Tendril response to touch
- ☑ Endocrine glands
- ☑ Stimulus-response pathway
11. NCERT-Based Board Questions
Q71. What is the function of receptors in our body?
Receptors detect changes in the environment.
They receive information about stimuli such as light, sound,
touch, taste, smell, heat and other changes and help initiate
appropriate responses.
Q72. Draw the structure of a neuron and explain its function.
A neuron receives information through its dendrites.
The information generates an electrical impulse that travels
through the cell body and axon.
At the axon terminal, chemicals are released across the synapse
to communicate with another neuron or target cell.
Diagram: Practise the labelled neuron diagram
given above.
Q73. How does phototropism occur in plants?
When light falls from one side, auxin produced at the shoot tip
moves towards the shaded side.
The cells on the shaded side grow more, causing the shoot to bend
towards the light.
Q74. Which signals will get disrupted in case of a spinal cord injury?
Signals travelling between the brain and the parts of the body
connected through the spinal cord may be disrupted.
This can interfere with sensory information travelling towards
the brain and motor instructions travelling towards body parts.
Q75. How does chemical coordination occur in plants?
Plants use chemical messengers called
plant hormones.
These hormones coordinate growth, development and responses
to environmental stimuli.
Examples include auxins, gibberellins, cytokinins and abscisic acid.
MUST DO
Q76. What is the need for a system of control and coordination in an organism?
Organisms interact continuously with their surroundings.
They need to detect environmental changes and respond appropriately.
Control and coordination ensure that different parts of the organism
work together and that suitable responses are produced.
Q77. How are involuntary actions and reflex actions different from each other?
Reflex actions are quick responses to particular stimuli and
generally involve reflex arcs.
Involuntary actions occur without conscious control and include
activities such as heartbeat, salivation and vomiting.
VERY IMPORTANT
Q78. Compare nervous and hormonal mechanisms of control and coordination in animals.
| Nervous Coordination | Hormonal Coordination |
|---|---|
| Uses electrical impulses through neurons. | Uses chemical messengers called hormones. |
| Generally provides rapid communication. | Hormones are transported through the blood. |
| Acts through connected nervous pathways. | Can reach target tissues through circulation. |
Q79. What is the difference between movement in a sensitive plant and movement in our legs?
The sensitive plant responds to touch without a nervous system or
muscles. Its cells change shape by changing their water content.
Movement of our legs is produced by muscles acting under the
coordination of the nervous system.
Q80. Why is the use of iodised salt advisable?
Iodine is required for the production of thyroxine by the thyroid
gland.
Iodine deficiency can lead to goitre.
Therefore, iodised salt is recommended as a source of iodine.
Q81. How does our body respond when adrenaline is secreted into the blood?
Adrenaline prepares the body for emergency action.
It causes the heart to beat faster, increases breathing rate and
directs more blood towards skeletal muscles.
Q82. Why are some patients of diabetes treated by giving injections of insulin?
Insulin regulates blood sugar level.
If sufficient insulin is not produced, blood sugar may rise.
Insulin injections can therefore be used as a treatment to help
control blood sugar levels when medically required.
12. Important MCQs – Control and Coordination
Q83. The gap between two neurons is called:
(a) Dendrite
(b) Synapse
(c) Axon
(d) Receptor
(a) Dendrite
(b) Synapse
(c) Axon
(d) Receptor
✔ Answer: (b) Synapse
Q84. The main thinking part of the human brain is:
(a) Fore-brain
(b) Mid-brain
(c) Hind-brain
(d) Spinal cord
(a) Fore-brain
(b) Mid-brain
(c) Hind-brain
(d) Spinal cord
✔ Answer: (a) Fore-brain
Q85. The part of the hind-brain responsible for posture and balance is:
(a) Medulla
(b) Cerebellum
(c) Spinal cord
(d) Fore-brain
(a) Medulla
(b) Cerebellum
(c) Spinal cord
(d) Fore-brain
✔ Answer: (b) Cerebellum
Q86. Reflex arcs are formed in the:
(a) Fore-brain
(b) Spinal cord
(c) Cerebellum
(d) Thyroid gland
(a) Fore-brain
(b) Spinal cord
(c) Cerebellum
(d) Thyroid gland
✔ Answer: (b) Spinal cord
Q87. Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxine
(c) Cytokinin
(d) Adrenaline
(a) Insulin
(b) Thyroxine
(c) Cytokinin
(d) Adrenaline
✔ Answer: (c) Cytokinin
Q88. Which hormone promotes cell division in plants?
(a) Cytokinin
(b) Abscisic acid
(c) Insulin
(d) Adrenaline
(a) Cytokinin
(b) Abscisic acid
(c) Insulin
(d) Adrenaline
✔ Answer: (a) Cytokinin
Q89. Which plant hormone inhibits growth?
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscisic acid
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscisic acid
✔ Answer: (d) Abscisic acid
Q90. Growth of a plant shoot towards light is called:
(a) Geotropism
(b) Phototropism
(c) Hydrotropism
(d) Chemotropism
(a) Geotropism
(b) Phototropism
(c) Hydrotropism
(d) Chemotropism
✔ Answer: (b) Phototropism
Q91. Which hormone is produced by the thyroid gland?
(a) Insulin
(b) Thyroxine
(c) Adrenaline
(d) Testosterone
(a) Insulin
(b) Thyroxine
(c) Adrenaline
(d) Testosterone
✔ Answer: (b) Thyroxine
Q92. Which gland produces insulin?
(a) Thyroid
(b) Pancreas
(c) Pituitary
(d) Adrenal gland
(a) Thyroid
(b) Pancreas
(c) Pituitary
(d) Adrenal gland
✔ Answer: (b) Pancreas
Q93. Adrenaline is secreted by the:
(a) Thyroid gland
(b) Pancreas
(c) Adrenal gland
(d) Pituitary gland
(a) Thyroid gland
(b) Pancreas
(c) Adrenal gland
(d) Pituitary gland
✔ Answer: (c) Adrenal gland
Q94. Which hormone regulates blood sugar level?
(a) Insulin
(b) Thyroxine
(c) Growth hormone
(d) Oestrogen
(a) Insulin
(b) Thyroxine
(c) Growth hormone
(d) Oestrogen
✔ Answer: (a) Insulin
Q95. Which hormone promotes stem growth in plants?
(a) Gibberellins
(b) Abscisic acid
(c) Insulin
(d) Adrenaline
(a) Gibberellins
(b) Abscisic acid
(c) Insulin
(d) Adrenaline
✔ Answer: (a) Gibberellins
Q96. Which hormone is associated with female sexual development and regulation of the menstrual cycle?
(a) Testosterone
(b) Oestrogen
(c) Insulin
(d) Adrenaline
(a) Testosterone
(b) Oestrogen
(c) Insulin
(d) Adrenaline
✔ Answer: (b) Oestrogen
Q97. Which part of the brain controls precision of voluntary actions?
(a) Cerebellum
(b) Medulla
(c) Spinal cord
(d) Thyroid
(a) Cerebellum
(b) Medulla
(c) Spinal cord
(d) Thyroid
✔ Answer: (a) Cerebellum
Q98. Which receptor detects smell?
(a) Gustatory receptor
(b) Olfactory receptor
(c) Touch receptor
(d) Visual receptor
(a) Gustatory receptor
(b) Olfactory receptor
(c) Touch receptor
(d) Visual receptor
✔ Answer: (b) Olfactory receptor
Q99. Growth of pollen tubes towards ovules is an example of:
(a) Phototropism
(b) Geotropism
(c) Chemotropism
(d) Hydrotropism
(a) Phototropism
(b) Geotropism
(c) Chemotropism
(d) Hydrotropism
✔ Answer: (c) Chemotropism
Q100. Which gland secretes growth hormone?
(a) Thyroid
(b) Pituitary
(c) Pancreas
(d) Adrenal
(a) Thyroid
(b) Pituitary
(c) Pancreas
(d) Adrenal
✔ Answer: (b) Pituitary
13. Case-Based Questions – Board Exam Practice
Case Study 1 – Reflex Action
A student accidentally touches a hot object and immediately pulls the hand away. The response occurs quickly without conscious thinking before the movement.
Q1. What type of action is this?
Q2. What pathway is involved?
Q3. Where is the reflex arc formed?
Answers:
1. Reflex action.
2. Reflex arc.
3. Spinal cord.
1. Reflex action.
2. Reflex arc.
3. Spinal cord.
Case Study 2 – Phototropism
A young plant is placed near a window. After a few days, the shoot is observed bending towards the light source.
Q1. Name the movement.
Q2. Which hormone is involved?
Q3. Where does auxin move when light falls from one side?
Q4. Why does the shoot bend?
Answers:
1. Phototropism.
2. Auxin.
3. Towards the shaded side.
4. Cells on the shaded side grow more, causing the shoot to bend towards the light.
1. Phototropism.
2. Auxin.
3. Towards the shaded side.
4. Cells on the shaded side grow more, causing the shoot to bend towards the light.
Case Study 3 – Hormonal Coordination
A person suddenly faces a frightening situation. The body prepares for rapid action. The heart beats faster and breathing rate increases.
Q1. Which hormone is responsible?
Q2. Which gland secretes it?
Q3. What happens to the heartbeat?
Q4. Why is more blood directed towards skeletal muscles?
Answers:
1. Adrenaline.
2. Adrenal gland.
3. Heartbeat becomes faster.
4. To prepare the body for rapid physical action.
1. Adrenaline.
2. Adrenal gland.
3. Heartbeat becomes faster.
4. To prepare the body for rapid physical action.
Case Study 4 – Thyroxine and Iodine
A student learns that iodine is necessary for the proper functioning of the thyroid gland and that iodine deficiency can cause goitre.
Q1. Which hormone is produced by the thyroid gland?
Q2. Why is iodine needed?
Q3. What disorder can result from iodine deficiency?
Q4. Why is iodised salt recommended?
Answers:
1. Thyroxine.
2. Iodine is necessary for the synthesis of thyroxine.
3. Goitre.
4. It provides iodine needed for thyroxine synthesis.
1. Thyroxine.
2. Iodine is necessary for the synthesis of thyroxine.
3. Goitre.
4. It provides iodine needed for thyroxine synthesis.
Case Study 5 – Nervous and Hormonal Coordination
The human body uses electrical impulses for rapid communication through neurons and hormones for chemical coordination through the blood.
Q1. What carries nervous information?
Q2. What carries hormones around the body?
Q3. Which system provides rapid electrical communication?
Q4. Name one hormone involved in emergency response.
Answers:
1. Electrical impulses through neurons.
2. Blood.
3. Nervous system.
4. Adrenaline.
1. Electrical impulses through neurons.
2. Blood.
3. Nervous system.
4. Adrenaline.
14. Quick Revision – Control and Coordination
| Concept | Key Point |
|---|---|
| Control & Coordination | Detection of changes and appropriate response. |
| Neuron | Basic nerve cell that conducts information. |
| Dendrite | Receives information. |
| Axon | Carries electrical impulse away from cell body. |
| Synapse | Gap between two neurons. |
| Receptor | Detects stimuli. |
| Reflex Action | Quick response to a stimulus. |
| Reflex Arc | Pathway involved in reflex action. |
| CNS | Brain + spinal cord. |
| Fore-brain | Main thinking part. |
| Cerebellum | Posture, balance and precision of voluntary actions. |
| Medulla | Controls several involuntary actions. |
| Phototropism | Response to light. |
| Geotropism | Response to gravity. |
| Hydrotropism | Response to water. |
| Chemotropism | Response to chemicals. |
| Auxin | Promotes growth and helps in phototropism. |
| Gibberellins | Promote stem growth. |
| Cytokinins | Promote cell division. |
| Abscisic Acid | Inhibits growth. |
| Adrenaline | Prepares body for emergency action. |
| Thyroxine | Regulates metabolism. |
| Growth Hormone | Regulates growth and development. |
| Insulin | Regulates blood sugar. |
| Testosterone | Male sexual development and puberty changes. |
| Oestrogen | Female sexual development and menstrual cycle. |
⭐ One-Minute Revision:
Stimulus → Receptor → Nervous System → Effector → Response
Dendrite → Cell Body → Axon → Axon Terminal
Reflex Arc → Spinal Cord
Fore-brain → Thinking
Cerebellum → Balance & Posture
Medulla → Involuntary Actions
Auxin → Growth / Phototropism
Gibberellins → Stem Growth
Cytokinins → Cell Division
Abscisic Acid → Growth Inhibition
Thyroxine → Metabolism
Insulin → Blood Sugar
Adrenaline → Emergency Response
Growth Hormone → Growth
Stimulus → Receptor → Nervous System → Effector → Response
Dendrite → Cell Body → Axon → Axon Terminal
Reflex Arc → Spinal Cord
Fore-brain → Thinking
Cerebellum → Balance & Posture
Medulla → Involuntary Actions
Auxin → Growth / Phototropism
Gibberellins → Stem Growth
Cytokinins → Cell Division
Abscisic Acid → Growth Inhibition
Thyroxine → Metabolism
Insulin → Blood Sugar
Adrenaline → Emergency Response
Growth Hormone → Growth
15. Class 10 Board Exam Final Checklist
- ☑ Understand the need for control and coordination.
- ☑ Learn the structure and function of a neuron.
- ☑ Learn how an impulse travels through a neuron.
- ☑ Learn the meaning of synapse.
- ☑ Learn receptors and their functions.
- ☑ Understand reflex action.
- ☑ Practise the reflex arc diagram.
- ☑ Learn the three major regions of the brain.
- ☑ Learn functions of fore-brain, cerebellum and medulla.
- ☑ Differentiate voluntary, involuntary and reflex actions.
- ☑ Learn how plants respond to stimuli.
- ☑ Learn sensitive plant movement.
- ☑ Learn phototropism and auxin.
- ☑ Learn geotropism, hydrotropism and chemotropism.
- ☑ Learn all four important plant hormones.
- ☑ Learn animal hormones and endocrine glands.
- ☑ Learn adrenaline and emergency response.
- ☑ Learn thyroxine and importance of iodine.
- ☑ Learn growth hormone and dwarfism.
- ☑ Learn insulin and blood sugar regulation.
- ☑ Learn testosterone and oestrogen.
- ☑ Practise neuron and brain diagrams.
- ☑ Practise tropism diagrams.
- ☑ Practise endocrine gland diagram.
- ☑ Practise NCERT exercise questions.
- ☑ Practise MCQs and case-based questions.
16. Exam Strategy for Control and Coordination
How to score better in this chapter?
1. Master the diagrams.
Practise the neuron, reflex arc, brain and endocrine gland diagrams until you can draw and label them without looking at the textbook.
2. Learn the hormone table.
Remember: Gland → Hormone → Function
3. Learn the differences.
Prepare:
5. Use exact scientific keywords.
Important terms include: receptor, neuron, dendrite, axon, synapse, electrical impulse, reflex arc, spinal cord, fore-brain, cerebellum, medulla, tropism, auxin, gibberellin, cytokinin, abscisic acid, adrenaline, thyroxine, insulin and feedback mechanism.
6. For 5-mark questions:
Write the answer in logical points, include examples and draw a labelled diagram whenever the question demands it.
Practise the neuron, reflex arc, brain and endocrine gland diagrams until you can draw and label them without looking at the textbook.
2. Learn the hormone table.
Remember: Gland → Hormone → Function
3. Learn the differences.
Prepare:
- Reflex action vs involuntary action
- Nervous coordination vs hormonal coordination
- Movement in sensitive plant vs movement in legs
- Phototropism vs geotropism
Stimulus
→
Receptor
→
Sensory Pathway
→
CNS
→
Motor Pathway
→
Effector
Important terms include: receptor, neuron, dendrite, axon, synapse, electrical impulse, reflex arc, spinal cord, fore-brain, cerebellum, medulla, tropism, auxin, gibberellin, cytokinin, abscisic acid, adrenaline, thyroxine, insulin and feedback mechanism.
6. For 5-mark questions:
Write the answer in logical points, include examples and draw a labelled diagram whenever the question demands it.
🎯 Learn Biology. Practise Diagrams. Score Better.
Revise Class 10 Science – Control and Coordination with NCERT-based important questions, answers, diagrams, MCQs, case-based questions and Board Exam revision.
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