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If pea plants with round and… (Class 10 Science 2025, Q11)

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ScienceCBSE Class 10 · Board exam 2025, set 31/1/1 · 1 mark · MCQ

CBSE Class 10 Science 2025: question 11

Set in the CBSE Class 10 board exam of 2025, paper 31/1/1, section A, question 11, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q11 · 1 mark · MCQHeredity

If pea plants with round and green seeds (RRyy) are crossed with pea plants having wrinkled and yellow seeds (rrYY), the seeds developed by the plants of generation will be:

  1. (A)50% round and green
  2. (B)75% wrinkled and green
  3. (C)100% round and yellow
  4. (D)75% wrinkled and yellow

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

Write the gametes each parent can make.

Hint 2

Which traits are dominant: round or wrinkled, yellow or green?

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. Gametes: RRyy gives only Ry and rrYY gives only rY.

  2. Every F₁ plant is RrYy. R is dominant over r and Y is dominant over y.

  3. So all F₁ seeds are round and yellow (100%), which is option (C).

    1 mark

Answer: 100% round and yellow, option (C)

Where the marks are

  • Chooses option (C) (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Heredity, 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.