Assertion (A) : When a bacterium divides into two, and the resultant two bacteria divide again, the four bacteria produced would be almost similar.
Reason (R) : DNA copying involves small inaccuracies in the reproduction process.
Generated by claude-sonnet-4-6 · 2026-06-15 06:43 · grounding rag
Model Answer
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
The bacteria are almost similar (not identical) because of small inaccuracies in DNA copying — so R actually does explain A, making (a) the correct choice.
> Answer: (a)
Both A and R are true, and R is the correct explanation of A. DNA copying involves small inaccuracies, so the resulting cells are similar but not identical — hence "almost similar," not exactly identical.
Explanation
- The passage states: "the DNA copies generated will be similar, but may not be identical… the surviving cells are similar to, but subtly different from each other" — this is caused by inaccuracies in DNA copying.
- Since the inaccuracy in DNA copying directly explains why bacteria are only almost similar (not exactly identical), R correctly explains A.
- Examiners expect students to link the cause (inaccurate DNA copying) to the effect (cells being almost similar, not identical). Option (a) is correct.