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Plants have neither a nervous… (Class 10 Science 2025, Q29)

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ScienceCBSE Class 10 · Board exam 2025, set 31/1/1 · 3 marks · Short answer

CBSE Class 10 Science 2025: question 29

Set in the CBSE Class 10 board exam of 2025, paper 31/1/1, section C, question 29, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q29 · 3 marks · Short answerCompetency-basedControl and Coordination

Plants have neither a nervous system nor muscles, even then they respond to stimuli. For example, the leaves of chhui-mui (touch-me-not) plant when touched begin to fold up and droop.

  1. (a)

    How is the information communicated in "touch-me-not" plants?

    0 marks
  2. (b)

    What enables the plant cells to bring out the observable response?

    0 marks
  3. (c)

    Differentiate the movement mentioned above from the movement of tendrils in a pea plant.

    0 marks

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

Hints

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

Hint 1

Plants have no nerves, but cells can still pass signals. What kind?

Hint 2

What makes a cell swell or shrink?

Hint 3

Does the tendril's movement involve growth? Does the touch-me-not's?

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) The plant has no nervous tissue. The information that touch has occurred is passed from cell to cell by electrical-chemical means.

    1 mark

  2. (b) Plant cells change shape by changing the amount of water in them. They swell or shrink as water moves in or out, and this makes the leaves fold up and droop.

    1 mark

  3. (c) Movement in touch-me-not is growth-independent, does not depend on the direction of the stimulus, and is a nastic movement. Movement of pea tendrils is growth-dependent and directional: the tendril grows towards and coils around the support. It is a tropic movement (thigmotropism).

    1 mark

Answer: (a) Electrical-chemical signals between cells; (b) change in water content (swelling/shrinking) of cells; (c) touch-me-not: growth-independent, non-directional (nastic); tendril: growth-dependent, directional (tropic)

Where the marks are

  • Information passed by electrical-chemical means (1 mark)
  • Cells change shape by changing their water content (1 mark)
  • Any one valid difference, e.g. growth-independent vs growth-dependent (1 mark)

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 31/1/1: 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.