Question

Define the term double fertilisation?

Answer 1

Double fertilization is a complex fertilization mechanism of flowering plants. This process involves the joining of a female gametophyte with two male gametes. It begins when a pollen grain adheres to the stigma of the carpel, the female reproductive structure of a flower. 

Answer 2

Double fertilisation is the combination of syngamy and triple fusion. Double fertilization is unique to flowering plants. ... One of the male gametes fuses with the nucleus of egg cell by the process of syngamy (first fertilisation) to form diploid zygote(2n).

Advantages: The first advantage of double fertilization in plants is that the plant does not invest energy in seed nutritive tissue until after an egg is fertilized. The second advantage is that the endosperm nucleus is very active and divides rapidly.