Skip to content

Answer the following. (Class 10 Science 2025, Q35B)

questionbuddy.in/q/cbse-10-science-2025-31-5-1-q35b

ScienceCBSE Class 10 · Board exam 2025, set 31/5/1 · 5 marks · Long answer

CBSE Class 10 Science 2025: question 35(B)

Set in the CBSE Class 10 board exam of 2025, paper 31/5/1, section D, question 35(B), for 5 marks. Try it first; the hints and our step-by-step solution are below.

Q35(B) · 5 marks · Long answerControl and Coordination

Answer the following.

  1. (a)

    Differentiate between voluntary and involuntary action.

    0 marks
  2. (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.

    0 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 31/5/1.

Hints

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

Hint 1

Ask whether you must think before doing the action, and which part of the brain controls it.

Hint 2

In a reflex arc, the impulse goes in by one type of neuron to the spinal cord and comes out by another type to a muscle.

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. (a) Difference 1: A voluntary action involves thinking and is done according to our will, e.g. writing. An involuntary action does not involve thinking and is not under our will, e.g. heartbeat.

    1 mark

  2. (a) Difference 2: Voluntary actions are controlled by the forebrain (cerebrum). Involuntary actions such as salivation and vomiting are controlled by the hindbrain (medulla).

    1 mark

  3. (b) Reflex action: a sudden, automatic response to a stimulus in the environment that occurs without conscious thinking, e.g. pulling the hand away from a hot object.

    1 mark

  4. (b) Flow diagram of the path of a nerve impulse: Stimulus → Receptor (in sense organ) → Sensory neuron → Spinal cord (relay neuron) → Motor neuron → Effector (muscle/gland) → Response.

    2 marks

Answer: (a) Voluntary: involves thinking, under our will, controlled by forebrain; involuntary: no thinking, not under our will, controlled by hindbrain. (b) Reflex action = sudden automatic response to a stimulus; Stimulus → Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector.

Where the marks are

  • Any two correct differences between voluntary and involuntary actions (1 + 1 mark)
  • Definition of reflex action (1 mark)
  • Correct flow diagram from stimulus to effector (2 marks)

Revise the chapter

Practise this chapterBoard-style questions from Control and Coordination, one at a time, marked against the answer key and marking points.Back to the full paper2025 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.