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Observe the given figure and… (Class 10 Science 2026, Q11A)

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ScienceCBSE Class 10 · Board exam 2026, set 31/5/1 · 2 marks · Very short answer

CBSE Class 10 Science 2026: question 11(A)

Set in the CBSE Class 10 board exam of 2026, paper 31/5/1, section A, question 11(A), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q11(A) · 2 marks · Very short answerHow do Organisms Reproduce?

Observe the given figure and identify the labelled parts P, Q, R and S :

Figure in the paper: Reflex arc diagram. A hand is placed on a hot pan (labelled P, pointing at the hand touching the pan). A nerve runs from the hand up the arm (labelled Q, on the nerve fibre from the hand toward the spinal cord, with arrows showing the impulse path). Label R marks the connection/relay point in the spinal cord, where the nerve passes into the grey matter of the spinal cord. Label S marks the muscle of the arm (biceps region) where the response occurs. The figure shows the spinal cord (CNS) at the top with an arrow labelled 'Message to brain' going upward from the spinal cord. See it in the official paper.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/5/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

This figure shows a reflex arc; trace the impulse from the hot pan to the arm.

Hint 2

The path is: receptor → neuron to spinal cord → connecting neuron → neuron to muscle → effector.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. P – Receptor (sense organ in the skin of the hand that detects heat).

    ½ mark

  2. Q – Sensory neuron (carries the impulse from the hand to the spinal cord).

    ½ mark

  3. R – Relay neuron (in the spinal cord, passes the impulse from sensory to motor neuron).

    ½ mark

  4. S – Effector (muscles of the arm that contract to pull the hand away).

    ½ mark

Answer: P – receptor (skin); Q – sensory neuron; R – relay neuron; S – effector (arm muscle)

Where the marks are

  • P identified as receptor (½ mark)
  • Q identified as sensory neuron (½ mark)
  • R identified as relay neuron (½ mark)
  • S identified as effector/arm muscle (½ mark)

Revise the chapter

Practise this chapterBoard-style questions from How do Organisms Reproduce?, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 31/5/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.