Question

A pollen grain with 120 chromosomes undergoes normal development. What will be the chromosome number in each male gamete formed later?

• A. 120
• B. 240
• C. 60
• D. 30

Hint:

Male gametes are produced by mitosis of the generative cell, so chromosome number remains unchanged.

Answer 1

The Correct Option is A

Pollen grains in flowering plants are haploid structures. They develop from haploid microspores formed after meiosis in the pollen mother cell. In the given question, the pollen grain already contains: \[ 120 \text{ chromosomes} \] This means: \[ n = 120 \] Inside the pollen grain:
• The generative cell undergoes mitotic division.
• Two male gametes are formed. Since mitosis does not alter chromosome number, each male gamete will also contain: \[ 120 \text{ chromosomes} \] No reduction division occurs during formation of male gametes from the generative cell. Option analysis:
• Option (A): Correct
• Option (B): Incorrect because chromosome number does not double.
• Option (C): Incorrect because meiosis is absent at this stage.
• Option (D): Incorrect Therefore: \[ \boxed{\text{(A)}} \]