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A tall pea plant with round… (Class 10 Science 2025, Q8)

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ScienceCBSE Class 10 · Board exam 2025, set 31/6/1 · 1 mark · MCQ

CBSE Class 10 Science 2025: question 8

Set in the CBSE Class 10 board exam of 2025, paper 31/6/1, section A, question 8, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q8 · 1 mark · MCQHeredity

A tall pea plant with round seeds (TTRR) is crossed with a short pea plant with wrinkled seeds (ttrr). The generation will be

  1. (A)25% tall with round seeds
  2. (B)50% tall with wrinkled seeds
  3. (C)75% tall with wrinkled seeds
  4. (D)100% tall with round seeds

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 31/6/1.

Hints

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

Hint 1

Work out the gametes each pure parent can make.

Hint 2

Every F₁ plant is TtRr. Which traits are dominant?

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. The TTRR parent gives only TR gametes and the ttrr parent gives only tr gametes. Every F₁ plant is therefore TtRr.

  2. Tall and round are dominant, so all F₁ plants are tall with round seeds (100%), option (D).

    1 mark

Answer: 100% tall with round seeds, option (D)

Where the marks are

  • Chooses option (D) (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 31/6/1: 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.