Formation of embryo sac and production of egg or female Gamete
(1) At first the nucleus of a female spore (n) divides to form two nuclei through mitosis, and each of these two nuclei moves to each pole
(2) The nucleus of each pole divides twice mitoticallv forming eight nuclei in total.
(3) Each nucleus is surrounded by cytoplasm and therefore they are also called individual cells.
(4) At this condition, the orientation of eight nuclei including the female spore (n) is called an Embryo sac.
(5) One end of the embryo sac remains towards the micropyle and the other end towards the chalaza
(6) At this time, mo nuclei, one from each pole mo‘ es to the middle of the embryo sac and they fuse together to form a definitive nucleus (2n)
(7) Three nuclei towards the micropyler end are called egg apparatus of which large nucleus at the middle is called egg or ovum or oosphere(n) and two other nuclei are called synergies.
(8) Three nuclei towards the chalazal end are called Antipodal cells.