Explanation

Development of Female Gametophyte (i) Megaspore mother cell undergoes the reductional/meiotic division that give rise to four megaspores (ii) Three of them die (in majority of plants) only one remains viable. This method of embryo sac formation is called monosporic development (iii) The nucleus of the functional megaspore divides mitotically to form two nuclei, which move to the opposite poles forming two nucleate embryo sac (iv) Two more sequential mitotic nuclear divisions results in the formation of four nucleate and later 8 nucleate stages of embryo sac (v) After the 8 nucleate stage cell walls are laid down leading to the organization of typical female gametophyte [image:2_image52.png]