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List the steps for… (Class 10 Science SQP 2024-25, Q23A)

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ScienceCBSE Class 10 · Sample paper, session 2024-25 · 2 marks · Very short answer

CBSE Class 10 Science sample paper 2024-25: question 23(A)

From the official CBSE sample question paper for 2024-25, section B, question 23(A), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q23(A) · 2 marks · Very short answerLife Processes

List the steps for the synthesis of glucose by the plants. What special feature is found in desert plants related to this process?

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2024-25.

Hints

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

Hint 1

Photosynthesis has three events, starting with capturing light.

Hint 2

Desert plants must save water. When would they open their stomata?

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. Step 1: Chlorophyll absorbs light energy.

    ½ mark

  2. Step 2: Light energy is converted into chemical energy, and water molecules split into hydrogen and oxygen.

    ½ mark

  3. Step 3: Carbon dioxide is reduced to carbohydrates (glucose): .

    ½ mark

  4. Special feature of desert plants: their stomata open at night, when they take in and store it as an intermediate. During the day, with stomata closed to save water, this intermediate is used with the light energy absorbed by chlorophyll to make glucose.

    ½ mark

Answer: Absorption of light by chlorophyll → conversion of light to chemical energy and splitting of water → reduction of CO₂ to carbohydrate; desert plants take in CO₂ at night as an intermediate and use it in the day.

Where the marks are

  • Absorption of light energy by chlorophyll (0.5 mark)
  • Conversion to chemical energy and splitting of water (0.5 mark)
  • Reduction of CO₂ to carbohydrates (0.5 mark)
  • Desert plants take in CO₂ at night as an intermediate used in daytime (0.5 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 paperSample paper 2024-25: 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.