Question

Mention the reason for difference in ploidy of zygote and primary endosperm nucleusin an angiosperm

Answer 1

Mention the reasons for the difference in ploidy of zygote and primary endosperm nucleus in an angiosperm. ... Zygote is formed by syngamy, so it is diploid in nature, and primary endosperm nucleus is formed by the fusion of secondary diploid nucleus with one of the male gamete, so it is triploid in nature.

Answer 2

The main reason in the difference in ploidy is just because of the difference in the ploidy level of the cell fuse to form them.

Explanation:

In Angiosperms, there is a  fusion of haploid egg and haploid male gamete , that result in the formation of diploid zygote.

                    Whereas, when one haploid male gamete fuses with diploid polar nucleus, it results in the formation of triploid endosperm.

Thus , zygote and endosperm varies in their ploidy level .