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Assertion (A) : Blood plasma… (Class 10 Science 2026, Q8)

questionbuddy.in/q/cbse-10-science-2026-31-2-1-q8-blood-plasma-transports-carbon-dioxide

ScienceCBSE Class 10 · Board exam 2026, set 31/2/1 · 1 mark · Assertion-reason

CBSE Class 10 Science 2026: question 8

Set in the CBSE Class 10 board exam of 2026, paper 31/2/1, section A, question 8, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q8 · 1 mark · Assertion-reasonCompetency-basedLife Processes

Assertion (A) : Blood plasma transports carbon dioxide in dissolved form, while oxygen is transported by respiratory pigments.
Reason (R) : Carbon dioxide is more soluble in water than in oxygen.

  1. (A)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
  2. (B)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
  3. (C)Assertion (A) is true, but Reason (R) is false.
  4. (D)Assertion (A) is false, but Reason (R) is true.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/2/1.

Hints

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

Hint 1

Which gas does haemoglobin carry?

Hint 2

Compare how soluble CO₂ and O₂ are in water.

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. Assertion: CO₂ is carried mainly dissolved in plasma, while O₂ is carried by haemoglobin, a respiratory pigment. True.

  2. Reason: CO₂ is more soluble in water than O₂ is. This is why plasma can carry CO₂ in dissolved form but not enough O₂, so R explains A. Option (A).

    1 mark

Answer: Option (A) (scheme also accepts (C), because of the wording of R)

Where the marks are

  • Selects (A); (C) also accepted (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 paper2026 board paper, set 31/2/1: 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.