Question

Explain the monosporic development of the embryo sac in the ovule of an angiosperm.

Answer 1

Development of embryo sac:

The first cell of the female gametophyte is represented by the functional megaspore that grows along the micropylar known as the chalazal axis and is primarily chalazal. The functioning megaspore's nucleus divides during phase to produce two cells that migrate to the opposing poles to form the 2-nucleate embryo sac. The 4-nucleate and eventually the 8-nucleate stages of the embryo sac are created by two more consecutive mitotic nuclear divisions. One nucleus from each group at a pole migrates to the cell's core, becoming known as a polar nucleus. The three remaining cells form antipodals and are encircled by a wall towards the end of the chalazal. The egg apparatus is made up of three cells at the micropylar end, one of which is an egg or female gamete and the other two are synergids. The adult female gametophyte or embryo sac is the entire structure with two polar cells, three antipodals, one egg, and two synergids.