CBSE Class 10 · Biology

CBSE Class 10 Biology Control and Coordination Previous Year Questions

Help your child master CBSE Class 10 Biology Control and Coordination with this expertly curated collection of previous year board exam questions spanning 2014–2024. Every question comes with a detailed answer and explanation — covering the nervous system, hormones, tropic movements, and reflex arcs — so your child walks into the exam fully prepared.

CBSE Class 10 Biology Control and Coordination — Questions with Solutions

Question 1 1 Mark 2022
Observe the three figures given below. Which of the following depicts tropic movements appropriately?

Tropic movements diagram showing three figures A, B and C
  • (A) B and C
  • (B) A and C
  • (C) B only
  • (D) C only
Solution
Option (D) is correct.

Explanation: The figure “C” depicts the phenomenon of geotropism appropriately. Geotropism is the growth of the parts of plants in response to the force of gravity. The upward growth of plant shoots is an instance of negative geotropism, while the downward growth of roots is an instance of positive geotropism.
Question 2 1 Mark 2019
The growth of tendril in pea plants is due to:
  • (A) effect of light.
  • (B) effect of gravity.
  • (C) rapid cell divisions in tendrillar cells that are away from the support.
  • (D) rapid cell divisions in tendrillar cells in contact with the support.
Solution
Option (C) is correct.

Explanation: When a tendril touches an object, the side in contact with the object grows slower than its other side (i.e., rapid cell divisions occur in the cells that are away from the support). This causes the tendril to bend towards the object, grow around it, and finally cling to it.
Question 3 1 Mark 2024
The cerebellum in the brain controls the voluntary actions of the body. Which of these actions is controlled by the cerebellum?
  • (A) Beating of the heart
  • (B) Blinking of the eyes
  • (C) Watering of the mouth
  • (D) Jumping from a height
Solution
Option (D) is correct.

Explanation: The cerebellum controls voluntary movements such as walking, posture, balance coordination, eye movements, and speech. This control results in smooth and balanced muscular activity.
Question 4 1 Mark 2016
In a synapse, chemical signal is transmitted from:
  • (A) Dendritic end of one neuron to axonal end of another neuron.
  • (B) axon to cell body of the same neuron.
  • (C) cell body to axonal end of the same neuron.
  • (D) axonal end of one neuron to dendritic end of another neuron.
Solution
Option (D) is correct.

Explanation: A synapse is a microscopic gap between two neurons where a chemical signal is transmitted from the axonal end of one neuron to the dendritic end of another neuron.
Question 5 1 Mark 2024
Receptors are usually located in sense organs. Gustatory receptors are present in:
  • (A) tongue
  • (B) nose
  • (C) eye
  • (D) ear
Solution
Option (A) is correct.

Explanation: The gustatory receptors, which detect taste, are present in the tongue.
Question 6 1 Mark 2023
In plants the role of cytokinin is:
  • (A) Promote cell division
  • (B) Wilting of leaves
  • (C) Promote the opening of stomatal pore
  • (D) Help in the growth of stem
Solution
Option (A) is correct.

Explanation: Cytokinin regulates cell division by promoting it in plants.
Question 7 1 Mark 2023
Sensory nerve of a reflex arc carries information from the receptor cells to the:
  • (A) spinal cord
  • (B) brain
  • (C) muscles of the effector organ
  • (D) bones of the receptor organ
Solution
Option (A) is correct.

Explanation: The sensory nerve of a reflex arc carries information from the receptor cells to the spinal cord. It is also called an afferent neuron.
Question 8 1 Mark 2024
Rajesh noticed that a potted plant kept in the window of his room shows bending towards sunlight. This could be due to:
  • (A) More growth in the well lit region due to diffusion of auxin hormone
  • (B) More growth in the region away from light due to diffusion of auxin hormone
  • (C) More growth in the well lit region due to diffusion of the cytokinin hormone
  • (D) More growth in the region away from light due to diffusion of cytokinin hormone
Solution
Option (B) is correct.

Explanation: Auxin becomes more concentrated on the side of the plant that is not facing the light (the shaded side). In the shoots, this causes the shaded side to grow more quickly, which results in the bending of the shoot towards the light.
Question 9 1 Mark 2019
‘Plant growth regulators do not always promote growth.’ Cite one example in support of the above statement and mention the action of the same.
Answer
Abscisic Acid (ABA):
It is a plant growth regulator that inhibits growth.

Action:
It is responsible for promoting ageing and senescence in plants.
Question 10 2 Marks 2016
How does auxin promote phototropism?
Answer
Auxin, a plant hormone synthesised at the shoot tips, helps the cells to grow longer. When light comes from one side of the plant, auxin diffuses towards the shady side of the shoot.

This concentration of auxin stimulates the cells to grow longer on the side of the shoot away from light. Thus, the plant appears to bend towards the light while growing.

This phenomenon is called phototropism.
Question 11 2 Marks 2023
(a) Name a plant hormone responsible for the bending of a shoot of a plant when it is exposed to unidirectional light. How does it promote phototropism?

(b) Plant hormones are also referred to as growth regulators and can be controlled by a number of stimuli. Mention one point of difference between the functioning of animal growth hormones and plant growth regulators with respect to such control.
Answer
(a) Auxin

When light comes from one side, auxin diffuses to the shaded side of the shoot. The higher concentration of auxin on the shaded side causes those cells to grow longer, making the shoot bend towards the light — this is phototropism.

(b) Animal growth hormones cannot promote growth under the influence of external stimuli like light, gravity, etc., while plant growth regulators can.
Question 12 2 Marks 2023
Where are auxins synthesised in a plant? Which organ of the plant shows:
(i) Positive phototropism
(ii) Negative geotropism
(iii) Positive hydrotropism
Answer
Auxins are synthesised in the growing regions at the tip of the shoot and root in a plant.

(i) Positive phototropismShoot
(ii) Negative geotropismShoot
(iii) Positive hydrotropismRoot
Question 13 2 Marks 2023
Hema bought some unripe tomatoes and left half of them in a brown paper bag and the other half in an open tray. After two days, she noticed that the tomatoes in the paper bag had ripened, but the ones in the open tray had not.

(a) Which hormone facilitated the ripening of tomatoes?
(b) Why did the tomatoes in the paper bag ripen faster?
Answer
(a) Ethylene

(b) Ethylene is a gaseous hormone, and the paper bag prevented it from diffusing into the air. Hence, the tomatoes ripened faster.
Question 14 2 Marks 2023
List two differences between the movement of leaves of a sensitive plant and the movement of a shoot towards light.
Answer
The type of movement of leaves of the sensitive plant is known as a nastic movement. This type of movement does not depend on the direction of stimuli.

The movement of the shoot towards light is known as a tropic movement. This movement depends on the direction of light and is directional and involves growth development.
Question 15 2 Marks 2016
Name the two components of the Peripheral Nervous System (PNS).
Answer
Cranial nerves arise from the brain and the spinal nerves arise from the spinal cord.
Question 16 2 Marks 2016
Mention the part of the brain which controls the involuntary actions like blood pressure and salivation.
Answer
Medulla in the hindbrain.
Question 17 2 Marks 2018
Sheila saw a snake and instantly jumped back. She then slowly moved away from the snake. What is the difference between the two actions of instantly jumping and walking away?
Answer
The jump was an involuntary quick reflex action.

Walking away was a voluntary slow action.
Question 18 2 Marks 2022
How is the mode of action in beating of the heart different from reflex actions? Give four examples.
Answer
Beating of Heart (Involuntary Actions)Reflex Actions
Involuntary actions are not controlled by our will.Reflex actions are sudden actions in response to something.
They do not need any external stimulus to work.They require a stimulus for their action.
These actions are regulated by the brain.These actions are regulated by the spinal cord.
They do not involve skeletal muscles.They involve skeletal muscles.

Examples of Involuntary Actions: Beating of heart, salivating, blinking of eyes, breathing.

Examples of Reflex Actions: Quick withdrawal of hand from a hot object, coughing, sneezing, shivering.
Question 19 2 Marks 2018
Different parts of the brain are associated with specific functions. Name the part of the human brain which performs the following functions:

(a) Sensation of feeling full
(b) Vomiting
(c) Picking up a pencil
(d) Riding a bicycle
Answer
(a) Hypothalamus
(b) Medulla / Hind Brain
(c) Cerebellum / Hind Brain
(d) Cerebellum / Hind Brain
Question 20 2 Marks 2023
Name the part of the brain which is responsible for the following actions:

(i) Maintaining posture and balance
(ii) Beating of heart
(iii) Thinking
(iv) Blood pressure
Answer
(i) Cerebellum
(ii) Medulla
(iii) Cerebrum
(iv) Medulla
Question 21 3 Marks 2023
Name the hormone secreted in scary situations by animals. Write any three responses which enable the animal body to deal with it.
Answer
Adrenaline or Epinephrine

The three responses that enable the animal body to deal with it are:

(i) Increased heart rate:
Adrenaline increases heart rate, enabling the animal to pump more blood and oxygen to the muscles. This helps the animal to react quickly to the perceived danger.

(ii) Dilated pupils:
Adrenaline causes the pupils to dilate, which helps the animal to see more clearly in low light conditions. This is essential for detecting potential threats and reacting quickly.

(iii) Increased blood sugar:
Adrenaline increases the release of glucose from the liver into the bloodstream, providing the animal with a quick source of energy. This helps the animal to perform physical activities required to defend itself or escape from danger.
Question 22 2 Marks 2023
What happens at the synapse between two neurons? State briefly.
Answer
Transmission of nerve impulses between two neurons takes place through the synapse. At the end of the axon, the electrical impulse sets off the release of some chemicals called neurotransmitters. These chemicals cross the gap (synapse) and start a similar electrical impulse in the dendrite of the next neuron.
Question 23 3 Marks 2020
(a) What is tropism?
(b) How do auxins promote the growth of a tendril around a support?
Answer
(a) Tropism:
It is the directional movement of a plant organ in response to an external stimulus.

(b)
Auxins produced in the shoot tip move downwards in the plant. These auxins cause cell elongation in the growing tissues. In the tendrils, auxins move away from the point of contact with the supporting object, while more growth occurs on the side away from the support. As a result of this unequal growth on the two sides, the tendril coils around the support.
Question 24 3 Marks 2018
What is geotropism? Draw a labelled diagram of a potted plant showing positive geotropism and negative geotropism.
Answer
The upward growth of shoots and downward growth of roots in response to the pull of earth’s gravity is called geotropism.

Labelled diagram showing positive and negative geotropism in a potted plant
Question 25 3 Marks 2020
A squirrel is in a scary situation. Its body has to prepare for either fighting or running away. State the immediate changes that take place in its body so that the squirrel is able to either fight or run.
Answer
  • The adrenaline hormone is secreted into the blood.
  • The heart beats faster resulting in supply of more oxygen to the muscles.
  • Blood is diverted to skeletal muscles.
  • The breathing rate increases.
  • The blood supply to digestive systems and skin is reduced.
Question 26 3 Marks 2020
Why is chemical communication better than electrical impulses as a means of communication between cells in a multi-cellular organism?
Answer
  • Electrical impulses have limited access to only those cells that are connected by nervous tissue/neurons, whereas chemical signals can reach each and every cell of the body.
  • Cells need time to reset in order to create repeated/new electrical impulses whereas no such time is required for chemical communication.
Question 27 3 Marks 2020
Name the parts (a) to (e) in the following diagram.

Reflex arc diagram with parts labelled a to e

What is the term given to the sequence of events occurring in the diagram?
Answer
(a) – Receptor / Skin
(b) – Sensory neuron
(c) – Spinal cord
(d) – Relay neuron
(e) – Motor neuron

The term given to the sequence of events occurring in the diagram is reflex arc.
Question 28 3 Marks 2019
Trace the sequence of events which occur when a bright light is focused on your eyes.
Answer
When bright light is focused on our eyes, the photoreceptors generate electric impulses and pass it to the sensory neurons. They carry the stimuli to the spinal cord which transports the message to the brain. The brain sends the response to the muscles of the eyelids to close by contracting the pupil.

Receptor → Sensory neuron → Spinal cord → Brain → Motor neuron → Eye → Contraction of eye muscles
Question 29 3 Marks 2019
Explain the feedback mechanism to regulate the action of the hormones with the help of one suitable example.
Answer
Feedback mechanism: Mechanism by which the amount of any chemical increases or decreases resulting in secretion of the related hormone.

Example:
  • When sugar level rises, insulin secretion increases.
  • When sugar level falls, insulin secretion reduces.
Question 30 3 Marks 2019
Pertaining to endocrine system, what will you interpret if:
(i) You observe swollen neck in people living in the hills.
(ii) Over secretion of Growth Hormone takes place during childhood.
(iii) Facial hair develop in boys aged 13.
Answer
(i) Less intake of iodine (in the diet).

(ii) Will lead to gigantism.

(iii) Timely secretion of testosterone.
Question 31 3 Marks 2017
Draw a neat diagram of human brain and label on it the following parts:
(i) Mid brain
(ii) Pituitary gland
(iii) Cerebellum
(iv) Cerebrum
Answer
Labelled diagram of the human brain showing mid brain, pituitary gland, cerebellum and cerebrum
Question 32 5 Marks 2019
What is hydrotropism? Design an experiment to demonstrate this phenomenon.
Answer
Hydrotropism: The movement/response of part of a plant (root) towards water.

Experiment:
  1. Soak the seeds in water overnight.
  2. Place moist cotton in a perforated petri dish.
  3. Put the soaked seeds in the petri dish and place it on a beaker.
  4. Roots pass through pores and grow downwards.
  5. After some time, roots will bend towards the base of the petri dish having moisture.
Question 33 5 Marks 2014
(a) Write the names and one function of each of any three growth hormones in plants.
(b) In the absence of muscle cells, how do plant cells show movement?
Answer
(a) Three growth hormones in plants are:
  1. Auxin: It is synthesised in the young tip of roots and shoots. It promotes elongation and division of cells and root formation.
  2. Gibberellins: They help in the growth of the stem.
  3. Cytokinins: They promote cell division and delay leaf ageing.

(b) In the absence of muscle cells, plant cells show two types of movements:

(i) Tropic movements are growth movements in response to an environmental stimulus. This type of movement may occur in response to gravity (geotropism), light (phototropism), water (hydrotropism), chemical (chemotropism), etc.

(ii) Nastic movements are independent of the direction of stimulus. This type of movement may occur in response to chemicals, temperature, touch, etc.

This shows that a plant cell can show movements in response to different stimuli although they do not have muscle cells.
Question 34 5 Marks 2019
(a) Why is the use of iodised salt advisable? Name the disease caused due to deficiency of iodine in our diet and state its one symptom.

(b) How do nerve impulses travel in the body? Explain.
Answer
(a)
Iodine is essential for the functioning of the thyroid / formation of thyroxine hormone.
Disease: Goitre.
One symptom of Goitre: Swollen neck.

(b)
  • Impulse travels from dendrite to the cell body, then along the axon to its end.
  • At the end of the axon, some chemicals (neurotransmitters) are released, which cross the synapse and initiate a similar electrical impulse in the next neuron.
  • The impulse then travels further in the body.
Question 35 5 Marks 2016
(a) Define receptor and state their location in our body. Mention any two receptors present in our forebrain and their functions.

(b) How do nerve impulses travel in our body?
Answer
(a)
Receptor: Specialized tips of some nerve cells that receive information from the surroundings.
Location: Sense organs (such as the eyes, ears, nose, tongue, and skin).

Examples of receptors in the forebrain and their functions:
  1. Gustatory receptor: Detects taste.
  2. Olfactory receptor: Detects smell.

(b)
Nerve impulses travel through neurons in a sequence of steps:
  1. Stimulus: A stimulus is detected by receptors and converted into an electrical impulse.
  2. Dendrites: The electrical impulse travels along the dendrites towards the cell body of the neuron.
  3. Axon: The impulse then moves down the axon, the long extension of the neuron.
  4. Synapse: When the impulse reaches the end of the axon, neurotransmitters are released across the synapse.
  5. Next neuron: The neurotransmitters trigger an electrical impulse in the next neuron, and the process continues until the impulse reaches its destination, such as the brain or muscles.
Question 36 5 Marks 2015
Define reflex arc. Draw a flowchart showing the sequence of events which occurs during sneezing.
Answer
The pathway taken by nerve impulses in a reflex action is called the reflex arc.

Sequence of events during sneezing:
  1. Nerve endings located in the nasal passage identify the irritant that has entered the nose.
  2. Receptors send the information or nerve impulses to the sneezing centre located in the brain stem.
  3. The brain stem sends instructions to the lungs or diaphragm for a response.
  4. The diaphragm moves abruptly, and chest muscles contract in response to the instructions received.
  5. Air blows out from the nose and mouth instantly and rapidly.
  6. Sneezing occurs as a response to the irritant.
Question 37 5 Marks 2024
(a) A doctor has advised Sameer to reduce sugar intake in his diet and do regular exercise after checking his blood test reports. Which disease do you think Sameer is suffering from? Name the hormone responsible for this disease and the organ producing the hormone.

(b) Which hormone is present in the areas of rapid cell division in a plant and which hormone inhibits the growth?
Answer
(a)
Sameer is suffering from diabetes.
The hormone responsible for this disease is insulin.
The organ producing the hormone is the pancreas.

(b)
The hormone present in the areas of rapid cell division in a plant is cytokinins.
The hormone that inhibits growth is abscisic acid.
Question 38 5 Marks 2024
(a) Sagar saw a beautiful rose and smelled it. As he was smelling it, he happened to touch a thorn and pull his hand away. State TWO differences and similarities each in the way the nervous system performs the two actions.

(b) Are all involuntary actions reflex actions? Justify.
Answer
(a)

Similarities:
  • In both cases, the signal is initiated by receptors located at the specific sense organ.
  • In both cases, neurotransmitters are released and accepted by neurons to carry the impulse.

Differences:
  • The action of smelling the rose is voluntary whereas pulling the hand away is involuntary in nature.
  • While smelling the rose, the nerve impulse reaches the brain and back, whereas on touching a thorn, the nerve impulse travels only to the spinal cord and back.

(b)
No, not all involuntary actions are reflex actions. Most involuntary actions do not require a stimulus to occur, as is necessarily required in the case of a reflex action.
Question 39 5 Marks 2016
The graph shows the average height of boys and girls in a population.

Graph showing average height of boys and girls with age

1. What does the graph indicate?

2. A student suggested a different title for the graph — ‘Height of boys and girls from birth to adulthood’. Is the title correct? Explain your answer.

3. Which of the following statements are correct? Circle ‘Yes’ or ‘No’ to mark your response.

StatementYes/No
Hormones are released directly into the bloodstream.Yes/No
Endocrine glands use electrical impulses.Yes/No
Sex hormones regulate changes associated with puberty.Yes/No
Answer
1. The graph indicates that the average height of girls during puberty is greater than that of boys.

2. The title is incorrect because the height of boys and girls from 0 to 3 years is not given.

3.
  • Hormones are released directly into the bloodstream. — Yes
  • Endocrine glands use electrical impulses. — No
  • Sex hormones regulate changes associated with puberty. — Yes

Frequently Asked Questions

What does the Control and Coordination chapter cover in CBSE Class 10 Biology?
The Control and Coordination chapter covers how living organisms respond to stimuli through the nervous system and hormonal (endocrine) system. Topics include the structure and working of neurons, reflex arcs, parts of the human brain, plant hormones (auxin, gibberellin, cytokinin, abscisic acid, ethylene), and tropic and nastic movements in plants. These concepts are consistently tested across all mark categories in board exams.
How many marks does Control and Coordination carry in the CBSE Class 10 board exam?
Control and Coordination is part of the Life Processes and Control unit in CBSE Class 10 Science. It typically contributes 8–10 marks in the board paper, appearing as 1-mark MCQs, 2-mark short answers, 3-mark descriptive questions, and occasionally as 5-mark long answer or case-study questions. Mastering this chapter gives your child a strong mark advantage.
What are the most important topics students should focus on in Control and Coordination?
The most frequently tested topics are: the reflex arc and reflex actions, functions of different parts of the brain (cerebrum, cerebellum, medulla), transmission of nerve impulses at the synapse, roles of plant hormones especially auxin and its role in phototropism, and the feedback mechanism for hormone regulation. Questions on adrenaline, insulin, and tropic movements also appear regularly.
What common mistakes do students make when solving Control and Coordination questions?
A very common error is confusing the roles of the cerebellum and the medulla — students often swap their functions in exam answers. Another frequent mistake is incorrectly explaining phototropism by saying auxin moves towards light rather than away from it. Students also confuse tropic (directional, growth-based) and nastic (non-directional) movements. Practising previous year questions like the ones above helps your child avoid these errors under exam pressure.
How does Angle Belearn help students score well in Control and Coordination?
Angle Belearn’s CBSE Biology specialists carefully curate chapter-wise question banks drawn from real board papers spanning multiple years, each paired with clear, step-by-step solutions. Students practising on Angle Belearn develop the habit of writing structured, point-wise answers — which is exactly what earns full marks in board exams. Regular practice with these verified questions builds both speed and confidence so your child walks into the exam fully prepared.