Question

An angiospermic male plant with $24$ chromosomes in its pollen mother cells is crossed with female plant bearing $24$ chromosomes in its root cells. What would be the ploidy of embryo and endosperm respectively formed after this cross?

• A. $24$ and $48$
• B. $24$ and $24$
• C. $48$ and $72$
• D. $24$ and $36$

Answer 1

The correct option is D $24$ and $36$

• The pollen mother cell is diploid in nature. It gives rise to the pollen grain by the process of meiosis. The root cell is diploid as it is a somatic cell.
• The haploid male gamete and egg cell thus have 12 chromosomes each which fuse to form the diploid embryo with 24 chromosomes.
• The endosperm is formed by the fusion of the haploid male gamete with the two haploid polar nuclei resulting in the formation of a triploid endosperm with 12+12+12= 36 chromosomes.

Thus, the correct answer is option D.