Megasporogenesis :- Biology

 Antipodal cells are group of three cells

present at the chalazal end. The two haploid

polar nuclei of large central cell fuse to form

diploid secondary nucleus or definitive

nucleus, just prior to fertilization. This seven-

celled and eight nucleated structure is called

an embryo sac. This method of embryo

sac development from a single megaspore

is described as monosporic development.

In angiosperms, the development of female

gametophyte is endosporous i.e. within the

megaspore. Female gametophyte is colourless,

endosporic and is concealed in the ovule

enclosed by ovary.