Question

Oogenesis involves:
A. Multiplication phase
B. Growth phase
C. Maturation phase
D. All of the above

Answer 1

Oogenesis is the process that occurs inside the female body in order to produce a female gamete. This process has three important stages that eventually leads to the generation of a mature female gamete, ovum.

Complete Solution:
The formation of an ovum is popularly referred to as oogenesis. It is the female gamete. The development of the different stages of the immature ovum is necessary. There are three phases: multiplication, growth and maturation.

Multiplication phase: Certain cells in the germ epithelium of the ovary of the fetus are larger than others in fetal growth. These cells are separated by mitosis, creating a few million egg mother cells or oogonia in each ovary of the fetus. Oogonia multiplied by mitotic divisions that formed the primary oocytes.

Growth stage: This is a very long stage of the primary oocyte. It will last for several years. Oogonium develops into a large primary oocyte. Primary oocyte is then surrounded by a layer of granulosa cells to form the primary follicle. A significant number of these follicles degenerate from birth to puberty. At puberty, therefore, only 60,000-80,000 primary follicles remain in each ovary.

Maturation phase: Every primary oocyte underwent two maturation divisions, the first meiotically and the other meiotically, like the primary spermatocyte. The primary oocyte split into two highly irregular, unequal haploid cells, a large secondary oocyte, and a very small first polar body in the first meiotic division. The first polar body can be split into two second polar bodies in the second maturation section. Once again, the secondary oocyte divides into unequal cells, a broad ootid and a small second polar body. The ootid becomes a haploid ovum which is functional. The three polar bodies are made from one oogonium, and one ovum. The ovum is the gamete of a female. The polar bodies are sterile and therefore degenerate quickly. In humans, the secondary oocyte stage releases an ovum from the ovary. In a mother's oviduct (fallopian tube), the secondary oocyte matures.

Therefore, choice (D) is the correct answer.

Note: Oogenesis consists of a multiplication process in which primordial germinal cells split regularly, a growth phase, where the primary oocyte's size increases greatly, and a maturation period occurs when a primary oocyte matures.