Control and Coordination Class 10 important questions with answers

What comes in the exam

• Control and Coordination is in the World of Living unit, which is worth 25 marks in all.
• 1-mark MCQs and 2-mark questions come most, then 3- and 5-mark questions, with some Assertion–Reason and a 4-mark case study.
• Almost every year you get reflex action and the reflex arc, the parts of the brain and what each one controls, plant hormones, tropic movements, the touch-me-not plant, and animal hormones such as adrenaline, insulin and thyroxin.
• The limits of electrical impulses, and why the body also needs hormones, come almost every year too, as 2-, 3- or 5-mark questions.

Top 10 Control and Coordination questions from board papers

Real CBSE questions, printed as they appeared. Open each answer to see the marking and the steps.

1. Q1 Very short answer · 2 marks CBSE · 2026

   How a sensitive plant moves

   The sensitive plant shows movement of leaves in response to touch. Explain such movement briefly.

   Answer and marking

   1. Touch makes the cells move water in or out. On touch, the plant cells change shape by changing the amount of water in them 1 mark
   2. Link the swelling or shrinking to the leaf folding. Swelling or shrinking of these cells makes the leaves fold 1 mark

   Answer: Cells change shape by changing water content ; swelling/shrinking makes the leaves fold

   Marks: Water change in cells 1 · Folding 1

   For full marks: Write 'by changing the amount of water in them' — that is how the cells change shape.

   Where students lose marks: Saying the leaves fold because they grow; this movement is quick and not due to growth.

   CBSE marking scheme

   In response to touch, plant cells change shape by changing the amount of water in them; swelling or shrinking of the cells makes the leaves fold (2).

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2. Q2 Very short answer · 2 marks CBSE · 2026

   Blocked pancreatic duct

   Varun is diabetic. His latest ultrasound reports showed a blockage in his pancreatic duct. How will this affect the dual functioning of the pancreas?

   Answer and marking

   1. The duct carries the digestive juice, so say what a block stops. Pancreatic enzymes cannot reach the small intestine, so digestion of proteins, carbohydrates and fats is affected 1 mark
   2. Insulin goes straight into blood, so link his diabetes to it. Insulin is secreted directly into the blood (endocrine), and it is already affected because he is diabetic 1 mark

   Answer: Digestive (exocrine) role blocked ; insulin (endocrine) role already affected by diabetes

   Marks: Digestive role 1 · Hormone role 1

   For full marks: Name both roles: enzymes for digestion and insulin into the blood — each role is one mark.

   Where students lose marks: Saying the duct block stops insulin; insulin goes straight into the blood, not through the duct.

   CBSE marking scheme

   Blocked duct: pancreatic digestive enzymes cannot reach the small intestine, so digestion of proteins, carbohydrates and fats is affected (1). Insulin secretion (endocrine, into blood) is already affected as he is diabetic (1).

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3. Q3 Very short answer · 2 marks CBSE · 2026

   Control of hormone amount

   "The timing and the amount of hormone secreted by a gland are regulated in the human body." Justify this statement with the help of an example.

   Answer and marking

   1. Name the control system that sets when and how much hormone is made. The timing and amount of hormone are regulated by a feedback mechanism 1 mark
   2. Use blood sugar and insulin as the example. When blood sugar rises, cells of the pancreas detect it and secrete more insulin ; as sugar falls, insulin secretion is reduced 1 mark

   Answer: Feedback mechanism ; e.g. high blood sugar ⇒ more insulin, low ⇒ less

   Marks: Feedback mechanism 1 · Example 1

   For full marks: Write the words 'feedback mechanism' — that term earns the first mark.

   Where students lose marks: Giving only the rise in insulin; the example needs both sides, more insulin when sugar rises and less when it falls.

   CBSE marking scheme

   Timing and amount are regulated by feedback mechanism (1). E.g. when blood sugar rises, pancreas cells detect it and secrete more insulin; as sugar falls, insulin secretion is reduced (1). Any other suitable example.

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4. Q4 Case study · 4 marks CBSE · 2026

   Case: forgetfulness and brain

   Read the following passage and answer the questions that follow: A middle-aged person is facing some cognitive changes in himself. His early symptoms included mild forgetfulness. For example, forgetting where he left his mobile or failing to find words to complete his sentences. He was facing problems in driving a car, climbing up and down the stairs, inserting a plug into an outlet. He slowly developed a sad mood and anxiety. (i) What are voluntary actions? (1) (ii) Which part of the brain is responsible for precision of voluntary actions? (1) (iii) (A) Explain the role of the medulla. (2) OR (B) How do the animal muscles move? (2)

   Answer and marking

   1. (i) Think of actions you choose to do, like writing. Voluntary actions are actions under our control, done according to our will; they are controlled by the fore-brain. 1 mark
   2. (ii) The part that makes willed movements precise sits at the back of the brain. Cerebellum 1 mark
   3. (iii) Say what kind of actions the medulla controls and give examples. The medulla regulates involuntary actions such as heart rate, blood pressure, breathing, sneezing and vomiting. 2 marks
   4. (iii) Explain what happens inside the muscle cell when a nerve impulse arrives. Muscle cells have special proteins that change their shape and arrangement in response to nerve electrical impulses ; the cells get shorter (contract) and this moves the body part. 2 marks

   Answer: (i) Actions done by our will, controlled by the fore-brain ; (ii) Cerebellum ; (iii) (A) medulla controls involuntary actions: heart rate, blood pressure, vomiting / (B) proteins in muscle cells change shape, cells shorten, body moves

   Marks: (i) 1 · (ii) 1 · (iii) 2

   For full marks: In (iii)(A) write 'involuntary actions' and give at least two examples like blood pressure and vomiting.

   Where students lose marks: Writing 'cerebrum' in (ii); the cerebrum starts voluntary actions, but their precision is the cerebellum's job.

   CBSE marking scheme

   (i) Actions under our control, done according to our will / controlled by fore-brain (1). (ii) Cerebellum (1). (iii)(A) Medulla regulates involuntary actions such as heart rate, blood pressure, breathing, sneezing, vomiting (2). OR (B) Muscle cells have special proteins that change shape and arrangement in response to nerve electrical impulses, making the cells shorter; this contraction moves the body (2).

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5. Q5 Case study · 4 marks CBSE · 2026

   Case: plant movements, stimuli

   Plants exhibit movements in response to various environmental stimuli to adopt and survive in their surroundings. These movements, influenced by external factors such as light, gravity, water and chemicals are regulated by specific plant hormones. For example, the differential growth of plant parts allows them to bend, grow or orient themselves in particular directions. Roots and shoots often show contrasting response to the same stimulus, highlighting the complex mechanisms involved in plant growth and development. (i) Why is hydrotropism essential for plants? (ii) What role does auxin play in the growth of plants? (iii) Differentiate between movement shown by the sensitive plant and tropic movement by plants (Two points). OR (iii) How does movement of roots differ from that of shoots in response to gravity and light?

   Answer and marking

   1. (i) Say what roots get by growing towards water. Roots grow towards water so that they can absorb water and minerals. 1 mark
   2. (ii) Auxin makes cells grow longer. Auxin promotes cell elongation and so causes the stem to bend towards light. 1 mark
   3. (iii) Give two clear contrasts, each with both sides. Sensitive plant: non-directional, fast, no growth involved ; Tropic movement: directional, slow, due to growth 2 marks
   4. (iii) Compare roots and shoots for gravity and for light. Roots: towards gravity (positive geotropism), away from light (negative phototropism) ; Shoots: away from gravity (negative geotropism), towards light (positive phototropism) 2 marks

   Answer: (i) To absorb water and minerals ; (ii) Auxin promotes cell elongation ; (iii) touch movement: fast, non-directional, no growth vs tropic: slow, directional, growth / roots: +geotropic, −phototropic; shoots: −geotropic, +phototropic

   Marks: (i) 1 · (ii) 1 · (iii) 2

   For full marks: Write each difference as a pair, both sides side by side: 'sensitive plant: fast ; tropic: slow'.

   Where students lose marks: Writing only one side of a difference, like 'sensitive plant is fast', earns no mark for that point.

   CBSE marking scheme

   (i) Roots grow towards water so they can absorb water and minerals (1). (ii) Auxin promotes cell elongation / regulates tropic bending of stem towards light (1). (iii) Sensitive plant: non-directional, fast, growth-independent; tropic: directional, slow, growth-related—any two (1+1). OR (iii) Roots: towards gravity (positive geotropism), away from light (negative phototropism); shoots: away from gravity (negative geotropism), towards light (positive phototropism) (1+1).

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6. Q6 Case study · 4 marks CBSE · 2023

   Case: brain and thinking

   In animals the control and coordination is provided by nervous and muscular tissues. Nervous tissue is made of an organized network of nerve cells or neurons. In human beings, thinking is a complex activity which involves more complex mechanisms and neural connections. These are concentrated in the brain which is the main coordinating centre of the human body. The brain and spinal cord constitute the Central Nervous System which receives information from all parts of the body and integrates it. (i) How is the brain protected from shocks and injuries ? (1) (ii) Write the main functions of (1) sensory neuron and (2) motor neuron in a reflex arc. (1) (iii) Which part of the brain is involved in activities like (1) picking a pencil and (2) vomiting ? State whether these actions are voluntary or involuntary. (2) OR (iii) How does the central nervous system communicate with other parts of the body to carry out various activities ? Name two components of this system. (2)

   Answer and marking

   1. (i) The brain sits inside a hard case of bone. Bony box (cranium) 0.5 marks
   2. Inside that case there is a cushion of fluid too. Fluid-filled balloon around the brain absorbs shocks. 0.5 marks
   3. (ii) Follow the message inwards first, from where it is sensed. (1) Sensory neuron carries information from receptors to the spinal cord. 0.5 marks
   4. Then follow it outwards to where the action happens. (2) Motor neuron carries it from the spinal cord to the effector muscle. 0.5 marks
   5. (iii) Picking a pencil needs precise, willed movement. Picking a pencil: cerebellum (hind-brain) ; voluntary 1 mark
   6. Vomiting happens without our will. Vomiting: medulla (hind-brain) ; involuntary 1 mark
   7. (iii) Name the system of nerves that links the CNS with the body. Through the peripheral nervous system. 1 mark
   8. List its two kinds of nerves. Cranial nerves and spinal nerves 1 mark

   Answer: (i) Cranium + fluid-filled balloon ; (ii) sensory: receptor → spinal cord; motor: spinal cord → muscle ; (iii) cerebellum, voluntary; medulla, involuntary / peripheral nervous system: cranial and spinal nerves

   Marks: (i) 1 · (ii) 1 · (iii) 2

   For full marks: In (iii) write 'voluntary' and 'involuntary' as well as the brain part; each word earns ½.

   Where students lose marks: Naming only the bony box in (i) and forgetting the fluid cushion loses ½.

   CBSE marking scheme

   (i) Bony box / cranium and a fluid-filled balloon (½ + ½). (ii) Sensory neuron carries information from receptors to the spinal cord; motor neuron carries it from the spinal cord to the effector muscle (½ + ½). (iii) Picking a pencil: cerebellum / hind-brain, voluntary; vomiting: medulla / hind-brain, involuntary (½ + ½ each). OR (iii) Through the peripheral nervous system (1): cranial nerves and spinal nerves (½ + ½).

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7. Q7 Long answer · 5 marks CBSE · 2026

   Impulse limits; plant movement

   (i) What are the limitations of electrical impulses in multicellular organisms ? (ii) (I) In a 'Touch-me-not' plant, movement is seen on touch. Compare it with that of animals. (II) Name the type of movement shown by the growth of pollen tube towards an ovule.

   Answer and marking

   1. (i) First limit: think about which cells a nerve can reach. Electrical impulses reach only those cells connected by nervous tissue, not every cell. 1 mark
   2. Second limit: a cell cannot fire again at once. After generating and transmitting an impulse, a cell needs time to reset before it can send a new one. 1 mark
   3. (ii)(I) Compare how the message travels and how the cells move in each. Touch-me-not: message passes cell to cell by electrical-chemical means, no special tissue ; cells change shape by changing water content ; Animals: special muscle tissue whose proteins change shape ; muscles contract and relax 2 marks
   4. (II) The pollen tube grows towards a chemical from the ovule. Chemotropism 1 mark

   Answer: (i) Reach only connected cells; cells need time to reset ; (ii)(I) plant: water content changes, no special tissue; animals: muscle proteins contract ; (II) Chemotropism

   Marks: Two limitations 2 · Comparison 2 · Movement type 1

   For full marks: In (ii)(I) write 'changing the amount of water' for the plant and 'muscle proteins change shape' for animals.

   Where students lose marks: Writing 'phototropism' or 'geotropism' in (II); the pollen tube responds to a chemical, so it is chemotropism.

   CBSE marking scheme

   (i) Impulses reach only cells connected by nervous tissue, not every cell (1); after generating and transmitting an impulse a cell needs time to reset before it can send a new one (1). (ii)(I) Touch-me-not: information passes cell to cell by electrical-chemical means, no specialised tissue; cells change shape by changing their water content (swelling/shrinking). Animals: specialised muscle tissue whose special proteins change shape; muscles contract and relax (2). (II) Chemotropism (1).

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8. Q8 Long answer · 5 marks CBSE · 2025

   Voluntary vs involuntary; reflex

   (a) Differentiate between voluntary and involuntary action. (b) Define reflex action. With the help of a flow diagram, show the correct sequence of path of nerve impulse from place of its origin.

   Answer and marking

   1. (a) Give two points, each comparing both kinds of action. Voluntary: involves thinking, controlled by fore-brain ; Involuntary: no thinking, controlled by hind-brain (or mid-brain) ; Voluntary: according to our will ; Involuntary: not according to our will 2 marks
   2. (b) Define it in one line. Reflex action is a sudden action in response to a stimulus in the environment. 1 mark
   3. Draw the chart from where the impulse starts to where the response happens. Stimulus → receptors → sensory neurons → spinal cord/brain → motor neuron → effector (muscle/gland) 2 marks

   Answer: (a) Voluntary: thinking, fore-brain, by will; involuntary: no thinking, hind-brain, not by will ; (b) sudden response to a stimulus; stimulus → receptor → sensory neuron → spinal cord → motor neuron → effector

   Marks: Differences 2 · Definition 1 · Flow diagram 2

   For full marks: Start the flow diagram at the stimulus and receptor, since the question asks for the path from its origin.

   Where students lose marks: Writing a point for only one side, like 'voluntary involves thinking', earns no mark for that difference.

   CBSE marking scheme

   (a) Any two: voluntary involves thinking / controlled by fore-brain / occurs according to our will; involuntary does not involve thinking / controlled by hind-brain (or mid-brain) / not according to our will (1+1). (b) Reflex action: sudden action in response to a stimulus in the environment (1). Stimulus → receptors → sensory neurons → spinal cord/brain → motor neuron → effector muscle/gland (2).

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9. Q9 Long answer · 5 marks CBSE · 2024

   Hormones; brain parts

   (i) Distinguish between hormonal co-ordination in plants and animals. (ii) Which part of the brain is responsible for – (1) intelligence (2) riding a bicycle (3) vomiting (4) controlling hunger (iii) How is brain and spinal-cord protected against mechanical injuries?

   Answer and marking

   1. (i) Say how plant hormones move and where they come from. Plants: hormones move by simple diffusion ; there are no specialised glands. 1 mark
   2. Now say the same for animals. Animals: hormones are secreted by endocrine glands and carried by blood to target organs. 1 mark
   3. (ii) Intelligence is a thinking job. (1) Intelligence: cerebrum (fore-brain) 0.5 marks
   4. Riding a bicycle needs balance and precise movement. (2) Riding a bicycle: cerebellum (hind-brain) 0.5 marks
   5. Vomiting is an involuntary action. (3) Vomiting: medulla (hind-brain) 0.5 marks
   6. Hunger is sensed by a centre in the fore-brain. (4) Controlling hunger: hypothalamus (fore-brain) 0.5 marks
   7. (iii) The brain sits in a bony case with a fluid cushion. Brain: bony box (cranium) with a fluid-filled balloon 0.5 marks
   8. The spinal cord runs inside the backbone. Spinal cord: vertebral column (backbone) 0.5 marks

   Answer: (i) Plants: diffusion, no glands; animals: endocrine glands, carried by blood ; (ii) cerebrum, cerebellum, medulla, hypothalamus ; (iii) cranium + fluid; vertebral column

   Marks: Differences 2 · Brain parts 2 · Protection 1

   For full marks: In (i) give both sides for each point: how the hormone travels and where it is made.

   Where students lose marks: Writing 'cerebrum' for riding a bicycle loses ½; balance and precise movement belong to the cerebellum.

   CBSE marking scheme

   (i) Plants: hormones move by simple diffusion; no specialised glands. Animals: hormones carried by blood to target organs; secreted by endocrine glands (1, 1). (ii) (1) cerebrum/fore-brain (2) cerebellum/hind-brain (3) medulla/hind-brain (4) hypothalamus/fore-brain (½ × 4). (iii) Brain: bony box (cranium) with fluid-filled balloon (½); spinal cord: vertebral column (½).

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10. Q10 Long answer · 5 marks CBSE · 2024

    Reflex arc and hot object

    (i) Define a reflex arc. Why have reflex arcs evolved in animals? Trace the sequence of events which occur, when you suddenly touch a hot object. (ii) Name the part of nervous system which helps in communication between the central nervous system and other parts of the body. What are the two components of this system?

    Answer and marking

    1. (i) Define the reflex arc as a pathway. A reflex arc is the pathway of nerve impulses during a reflex action. 1 mark
    2. Say why animals need this shortcut. The thinking part of the brain is not fast enough ; a quick response avoids injury. 0.5 marks
    3. Trace the message from the skin to the muscle in order. Receptor in skin → sensory neuron → relay neuron in spinal cord → motor neuron → effector muscle → hand is withdrawn 1.5 marks
    4. (ii) Name the system of nerves that links the CNS with the body. Peripheral nervous system 1 mark
    5. Its first kind of nerve comes from the brain. Cranial nerves 0.5 marks
    6. Its second kind of nerve comes from the spinal cord. Spinal nerves 0.5 marks

    Answer: (i) Pathway of impulses in a reflex action; brain too slow; receptor → sensory neuron → spinal cord → motor neuron → muscle ; (ii) Peripheral nervous system: cranial and spinal nerves

    Marks: Definition 1 · Reason ½ · Sequence 1½ · PNS 2

    For full marks: Write the reason in full: 'the thinking part of the brain is not fast enough' for the ½.

    Where students lose marks: Skipping the spinal cord (relay) or starting the chain at the muscle; the sequence must start at the receptor.

    CBSE marking scheme

    (i) Pathway of impulses during a reflex action (1); evolved because the thinking part of the brain is not fast enough — quick response avoids injury (½); sequence: receptor in skin → sensory neuron → spinal cord (relay) → motor neuron → effector muscle withdraws hand (1½). (ii) Peripheral nervous system (1); cranial nerves and spinal nerves (½; ½).

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Free 10-question test: Control and Coordination

MCQ and Assertion–Reason questions from CBSE papers. About 10 minutes. Your score shows straight away.

Common mistakes in Control and Coordination

How to write for full marks

• Draw the reflex arc as a flow chart with arrows and the exact names: receptor, sensory neuron, relay neuron, motor neuron, effector. In a labelled figure, each correct label earns ½ mark.
• For 'state two differences', write each point as a pair on the same basis, like 'voluntary: needs thinking / involuntary: no thinking'. Each pair carries 1 mark.
• For 'define reflex action', write a one-line definition first, then the flow chart. They carry separate marks.
• For a hormone problem such as goitre, dwarfism or changes at puberty, name the gland or hormone and link it to the effect in one line. Each situation carries 1 mark.
• For plant movements, name the stimulus and say if the part grows towards it or away from it, for the root and the shoot both.

Not in the 2026-27 exam

Leave these out of your revision.

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