In the ovule , a diploid mother cell undergoes meiosis to produce four haploid cells.
Only one of these enlarges to from the embryo sac. The others disintegrate. The haploid nucleus that remains undergoes repeated mitosis until eight nuclei are produced .
Two nuclei migrate to the centre of the embryo sac. Three nuclei will move to each end of the sac. Five of these will disintegrate, leaving one near the micropyle end of the ovule -that is, a small opening between the protective covers of the ovule.This is the female gamete.