Question

Identify the ploidy of embryo and endosperm respectively formed after following cross.

An angiospermic male plant with 24 chromosomes in its pollen mother cells is crossed with female plant bearing 24 chromosomes in its root cells.

Options

• 48 and 72

• 24 and 24

• 24 and 48

• 24 and 36

Answer 1

24 and 36

Explanation:

Pollen grains will have 12 chromosomes because the diploid pollen mother cells have 24 chromosomes. Male gametes will thus have l 2 chromosomes. Because the female gamete is haploid, she will have 12 chromosomes. As a result, syngamy produces a diploid zygote with 24 chromosomes. Three haploid nuclei with 12 chromosomes each will be fused in a triple fusion. As a result, the 36 chromosomes of triploid endosperm will be present.