Question 91 markMCQSection A

Assertion (A): Bacteria produced as a result of asexual reproduction would be similar.

Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

How do Organisms Reproduce?
Variation in Asexual Reproduction

Options

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

Official answer

A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Marking scheme

  1. 1.1 mark for correctly selecting option (A).

Hint

Think about why DNA copying errors, described in the book as small inaccuracies, still allow offspring to remain largely similar to the parent.

Common mistakes

  1. 1.Thinking bacteria produced asexually are genetically identical (ignoring that copying is never 'absolutely reliable').
  2. 2.Assuming minor DNA copying errors imply Reason is false or unrelated to Assertion.

Analysis and explanation

The chapter explains: "No bio-chemical reaction is absolutely reliable. Therefore, it is only to be expected that the process of copying the DNA will have some variations each time. As a result, the DNA copies generated will be similar, but may not be identical to the original." This directly supports Assertion (A) — bacteria produced asexually are broadly similar to the parent and to each other, since asexual reproduction (fission) involves a single parent copying its own DNA. Reason (R) correctly explains why they are similar-but-not-identical: DNA copying, though precise, has small inaccuracies each generation, producing only minor variations rather than drastic differences. Since R correctly explains why A is true (similarity persists because inaccuracies are only minor), option (A) is correct.


Why the distractors fail: (B) is wrong because R does in fact correctly explain A — the minor nature of the copying errors is precisely why the offspring remain similar rather than becoming widely different. (C) is wrong because R is true, not false — the text explicitly states DNA copying has "some variations" that are generally small, not drastic, in each replication event. (D) is wrong because A is true, not false — bacteria from asexual reproduction are indeed similar to one another, as they arise from copying a single organism's DNA.

Question details

Q9 of 39 questions

Board
CBSE
Class
Class 10
Subject
Science
Year
2026
Section
Section A
Marks
1
Type
MCQ
Chapter
How do Organisms Reproduce?
Topic
Variation in Asexual Reproduction
Bloom's level
Analyze
Syllabus topic
7.1 Do Organisms Create Exact Copies of Themselves?

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Frequently asked questions

How many marks does this question carry in CBSE Class 10 Science 2026?

This question carries 1 mark in the CBSE Class 10 Science 2026 examination.

Which chapter does this question come from in Science?

This question is from the chapter "How do Organisms Reproduce?" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Variation in Asexual Reproduction" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2026 paper?

This is a MCQ question from Section A in the CBSE Class 10 Science 2026 paper.