Question

Why does a pollen grain possess two male gametes? Explain.

Answer 1

A pollen grain contains two male gametes. One of the male gametefuses with female gamete to form zygote and the other one fuses with the polar nuclei to form the primary endosperm nucleus. ...Pollen sacs contain pollen grains.

Answer 2

Pollen grain possess two male gametes for double fertilization in most angiosperm.

Explanation:

This is a development from the previous plant varieties. There are two male gametes in a pollen grain. One is for egg(n) and the other is for central cell (2n).

One of this gamete fuses with egg which forms formed zygote and resulting to the embryo in the later process. The other gamete fuses with central cell(2n) to form  “triploid primary endosperm cell(3n)” which will then form as a endosperm to produce food to the embryo.