Question

In fertilisation, how many times does the fusion take place?

Answer 1

In plants the fusion takes place twice and is known as double fertilisation.

Double fertilization is a characteristic feature of flowering plants. In the process of double fertilization out of the two sperm nucleus produced by pollen grain, one sperm nucleus fuses with the egg nucleus to form an embryo ( process is called syngamy) and another fuses with polar nuclei to form endosperm ( process is called triple fusion).

Since two kinds of fusion—syngamy and triple fusion—take place, the process is known as double fertilisation.