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We water the soil but it… (Class 10 Science 2024, Q29)

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

CBSE Class 10 Science 2024: question 29

Set in the CBSE Class 10 board exam of 2024, paper 31/3/1, section C, question 29, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q29 · 3 marks · Short answerLife Processes

We water the soil but it reaches the topmost leaves of the plants. Explain in brief the process involved.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/3/1.

Hints

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

Hint 1

Which tissue carries water in plants?

Hint 2

What happens to water at the leaf surface, and how does that 'pull' on the water below?

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. Absorption: Root cells take in water and minerals from the soil. Water enters the root xylem, and the vessels and tracheids of roots, stems and leaves form a continuous channel.

    1 mark

  2. Transpiration: Water evaporates from the leaf cells and is lost through the stomata. This loss of water vapour from the aerial parts is called transpiration.

    1 mark

  3. Transpiration pull: The loss of water creates a suction force (transpiration pull). This pulls the continuous column of water upward through the xylem from the roots to the topmost leaves. Root pressure also helps, especially at night.

    1 mark

Answer: Water lost from leaves by transpiration through the stomata creates a suction (transpiration pull), which draws water up through the continuous xylem from the roots to the leaves.

Where the marks are

  • Water lost through stomata by transpiration (1 mark)
  • This creates suction/transpiration pull (1 mark)
  • Water is pulled up through the xylem from roots to leaves (1 mark)

Revise the chapter

  • Chapter: Life Processes (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Life Processes, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 31/3/1: 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.