Question

Why is a single ovum produced by Oogenesis?

Answer 1

The main function of the ovum is to hold the set of chromosomes contributed by the feminine gamete. It creates the proper environment for fertilization to occur with the assistance of sperm. It also provides nutrients to the growing embryo until it sinks into the uterus and further, the placenta takes over.

Complete answer:
Female gametogenesis or oogenesis produces mature eggs. Just one egg is produced from 4 haploid cells as a result of meiosis. Oogenesis proceeds with the primary oocyte undergoing the first meiotic division forming a secondary oocyte (haploid). Secondary oocytes undergo a second meiosis division forming a haploid ovum (if fertilized by sperm).
Hence, one egg results from meiosis which contains the foremost nutrients, cytoplasm, organelles. The unequal distribution of drugs gives rise to at least one large cell, and one cell with more DNA (polar body which gradually degenerates). The larger cell undergoes meiosis II producing a cell and an outsized cell again, and this massive cell becomes the ovum.
Oogenesis is the process of manufacturing the feminine gametes, the Ovum, from the primordial germ cells. The bulk of the steps in oogenesis, up to the purpose of manufacturing primary oocytes, occur pre-naturally.
The phenomenon of formation of haploid ova(egg) from the diploid egg mother cells of the ovaryN(female gonad) is called oogenesis. It occurs in three phases i.e., Multiplication phase, growth phase and maturation phase.

Note:
Oogenesis—the differentiation of the ovum—differs from spermatogenesis in several ways. Whereas the gamete formed by spermatogenesis is actually a motile nucleus, the gamete formed by oogenesis contains all the materials needed to initiate and maintain metabolism and development.