Question

Assertion :If pollen mother cells has 42 chromosomes, the pollen has only 21 chromosomes. Reason: Pollens are formed after meiosis in pollen mother cell.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Both Assertion and Reason are incorrect.

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

Each microsporangium has inner sporogenous tissue that differentiates into microspore/pollen mother cell or first undergoes mitotic divisions to increase the cell number. The sporogenous cells are diploid and have two complete sets of chromosomes. These diploid cells undergo meiosis to produce four haploid microspores/pollen grains. Hence, if the pollen mother cell has 42 chromosomes, the pollen has 21 chromosomes. Assertion is correct. This is due to the fact that pollens are product of meiosis in microspore mother cells which is a reductional division and reduced the number of chromosomes to half in the daughter cells as compared to their parent cells. Reason is correct and gives correct explanation of Assertion.

Thus, the correct answer is option A.