What is the function of the two male gametes produced by each pollen grain in angiosperms.

The two male gametes produced by each pollen grain in angiosperms helps in double fertilisation.

i. One of the male gametes moves towards the egg cell and fuses with its nucleus called Syngamy. This results in the formation of a diploid cell, the zygote.

ii. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN) (Figure 2.13a).

As this involves the fusion of three haploid nuclei it is termed triple fusion.

Two types of fusions, syngamy and triple fusion, take place in an embryo sac the phenomenon is termed double fertilisation, an event unique to flowering plants.