Question

Briefly describe double fertilization

Answer 1

Answer:

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

Answer:

double fertilization

Involves the fusion of male and female gametes (syngamy) and fusion of male gamete with a secondary  nucleus (triple fusion)  After discharge from the pollen tube, one of the male gametes fuses with the egg and forms the oospore  (zygote). This is called true fertilisation (also called syngamy = amphimixis). The oospore is diploid (2n).

The second male gamete fuses with the secondary nucleus (2n) and forms a triploid (3n) nucleus, called  the endosperm mother nucleus. This is called triple fusion. Thus both the male gametes participate in  fertilisation, i.e., fertilisation takes place twice.

This is called double fertilisation. (Double fertilisation includes syngamy as well as triple fusion), zygote  produced, as a result of syngamy develops into an embryo and the triploid nucleus (Endosperm mother  nucleus), develops into the endosperm which is used for nutrition of embryo. Antipodals and synergids  degenerate after fertilisation.