In the given diagram of a pistil,in which part does fertilization take place?

The total number of nuclei involved in double fertilization in angiosperms is

Number of nuclei taking part in double fertilization is

In angiospermic fertilisation,one male gamete fuses with the egg to form $A$,and this event is called $B$. Identify $A$ and $B$ and choose the correct option.

Double fertilization is essential for the formation of:

The genotype of the endosperm is $ZZA$. Find out the genotype of the male and female plant,respectively.