Question

In a 30 year old lady , eggs are released in the form of
A. Oogonia
B. Primary oocyte
C. Secondary oocyte
D. Atretic follicle

Answer 1

Hint: Gametogenesis is the process in which a haploid cell is formed from a diploid cell through meiosis and cell differentiation. Gametogenesis in male is known as spermatogenesis and in females is known as oogenesis.

Complete Answer:
- Oogonia are the basis of a renewing stem germ cell population in the ovary. They split mitotically, increasing in number. Oogonia ranges from 8–12 μm in diameter and their shape is spherical or ovoidal. Oogonia have a translucent ooplasm.
- The nucleus is ovoidal, composed of a single nucleolus and fine granular chromatin. The oogonia are speckled in the germinal epithelium as individual cells or form small groups in cell nests. Normally, oogonia in a cell nest are associated by intercellular bridges and undergo synchronous development.
- The oocyte that originates from the oogonium through the process of oocytogenesis and which gives rise to secondary oocyte is and the polar body after the first meiotic division is called primary oocyte.
- In human beings the primary oocyte is produced by the process of oocytogenesis. The primary oocyte will not complete meiosis I but stopped at phase I of meiosis. It will only complete meiosis at the time of ovulation.
- Secondary oocytes are the immature ovum soon after ovulation to fertilization where it turns into ootid. This is the resulting oocyte when meiosis is completed and which gives rise to ootid and ovum which is the egg cell only after the completion of meiosis.
- The secondary oocyte will be halted at the stage of metaphase II of meiosis II until the fertilization takes place when a sperm cell comes in contact with the female ovum the secondary oocyte rapidly completes the remaining stage of meiosis II and give rise to an ootid and an ovum.
- Atrectic follicle is a follicle that degenerates before coming to maturity. Many numbers of atretic follicles are formed in the ovary before attaining maturity in sexually mature women.

So the correct answer is option C secondary oocyte.

Note: The secondary oocyte promotes fertilization. It releases molecules that guide the sperm and the surface of the eggs to get attached to the sperm surface.