Amoeba reproduction — Assertion–Reason UPSC Prelims PYQ 2005

Consider the following statements:

1. Assertion (A): Amoeba is reproduced by fission.
2. Reason (R): All unicellular organisms are reproduced by asexual methods.

Which of the statements is/are correct?

1. Both (A) and (R) are individually true and R is the correct explanation of A
2. Both (A) and (R) are individually true and R is not the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Explanation

Option (c) is correct

• Amoeba reproduces primarily through binary fission, an asexual mode of reproduction; hence Assertion (A) is true. However, the Reason is false because not all unicellular organisms reproduce exclusively by asexual methods. Several unicellular organisms, such as Paramecium and yeast, can also undergo forms of sexual reproduction or genetic recombination (e.g., conjugation). Therefore, the statement that all unicellular organisms are reproduced by asexual methods is incorrect. Hence, A is true but R is false.

Answer: (c) A is true but R is false