Question

The formation of an embryo sac is called
(a)Megasporogenesis
(b)Megagametogenesis
(c)Microgametogenesis
(d)None of the above

Answer 1

Hint The embryo sac is situated in the ovule and gives rise to the endosperm and zygote. Which are formed from the egg cell and the diploid nucleus after the fertilization.

Complete answer:
The formation of the embryo sac is known as mega gametogenesis which is the process of maturation of the female gametophyte in plants and during which the megaspore arises from megasporogenesis which gets developed into the embryo sac where the female gamete is housed. The developing embryo undergoes meiosis during the process of megasporogenesis which involves certain steps that is the remaining megaspore undergoes around of mitosis which results in the structure with the two nuclei known as binucleate embryo sac and each nucleus migrate to opposite sides of the embryo sac. The haploid nucleus undergoes two rounds of mitosis which creates four haploid nuclei on each end of the embryo sac. The nucleus from each set of the embryo sac migrates to the center and forms the binucleate endosperm mother cell which leaves three remaining nuclei on the micropylar end. The cell plates form around the entire portal nuclei egg cell and the synergid cells.

Additional information:
Megasporogenesis: The development of mega sports from the megasporocyte is megasporogenesis in which the cell undergoes meiosis. The meiosis of mega sporophyte nucleus results in the formation of haploid megaspore nuclei and the pattern is known as monosporic megasporogenesis because of the four megaspores which are produced and that contributes to the female gametophyte. The cytokinesis occurs after the first meiotic division and results in cells that contain two haploid nuclei in each of them.
Microgametogenesis: The process involving the reproduction in plants where a microgametophyte gets to develop in a Pollen grain in its three celled stages of development and occurs within a microspore mother cell in flowering plants inside the anther of the plant.

So, the correct answer is 'Megagametogenesis'.

Note: Gametogenesis plays a significant role in mammal reproduction through which the germ cell lineage undergoes the complex developmental processes and the formation of matured gametes takes place.