Skip to content

Define reflex action. With… (Class 10 Science 2024, Q30)

questionbuddy.in/q/cbse-10-science-2024-31-1-1-q30-define-reflex-action-help-flow

ScienceCBSE Class 10 · Board exam 2024, set 31/1/1 · 3 marks · Short answer

CBSE Class 10 Science 2024: question 30

Set in the CBSE Class 10 board exam of 2024, paper 31/1/1, section C, question 30, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q30 · 3 marks · Short answerControl and Coordination

Define reflex action. With the help of a flow chart show the path of a reflex action such as sneezing.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/1/1.

Hints

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

Hint 1

A reflex happens without our thinking about it. Which part of the nervous system controls it?

Hint 2

Arrange these in order: receptor, sensory neuron, relay neuron, motor neuron, 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. Reflex action is a sudden, automatic (involuntary) response to a stimulus, made without conscious thinking. Example: sneezing.

    1 mark

  2. Flow chart for sneezing: Stimulus (irritant/dust in nose) → Receptors in the nasal lining → Sensory neuron → Relay neuron in the CNS (spinal cord / brainstem) → Motor neuron → Effector (muscles of the chest/diaphragm) → Response (sneeze, forcing air out).

    2 marks

Answer: Reflex action is a sudden involuntary response to a stimulus; stimulus → receptor (nose) → sensory neuron → relay neuron (spinal cord) → motor neuron → effector (muscles) → response

Where the marks are

  • Correct definition of reflex action (1 mark)
  • Correct reflex arc flow chart in the right sequence (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 paper2024 board paper, set 31/1/1: 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.