Which are the nuclei that fuse to form endosperm?

Which one forms the endosperm

Which one forms the endosperm

Which one forms the endosperm

Polar nuclei fuse to produce

Polar nuclei fuse to produce

Give reason for the following In angiosperms, one of the male gametes fuses with egg to form zygote and second male gamete fuses with polar nuclei to form primary endosperm nucleus.

In double fertilisation, one male gamete fuses with the (i) to form zygote and the other male gamete fuses with (ii) to form primary endosperm nucleus.