Where does triple fusion take place in a flowering plant? Why is it so called? Mention its significance.

The fusion involving two polar nuclei and a sperm nucleus that occurs in double fertilization in a seed plant and results in the formation of the endosperm is called triple fusion.

It takes place in the embryo sac in the angiosperms (also called flowering plants).

It is known as triple fusion because it involves the fusion of two polar nuclei with one sperm nucleus, that results in the formation of endosperm.

It is significant because the endosperm formed as a result is very important for developing an embryo. Endosperm provides the embryo with all the nutrition that it needs during the early days of its development. Endosperm is triploid in nature.