Question

Differentiate between spermatogenesis and oogenesis.

Answer 1

Hint: Spermatogenesis and oogenesis are the processes of formation of male and female gametes respectively. Male gamete that is sperms is produced through the process of spermatogenesis and eggs, female gametes are produced through oogenesis. These gametes fuse to form a single cell called zygote which develops into a complete organism.

Complete answer:
Spermatogenesis readily produces sperms and oogenesis is responsible for producing eggs which fuse to form a zygote. Since, these two processes produce the same thing that is gametes but they have a lot of differences in their processes, here we would discover those differences.

Sr.No	SPERMATOGENESIS	OOGENESIS
1.	This process occurs inside testis.	This process occurs inside ovaries.
2.	All the stages of gamete formation takes place in the same place that is testis.	Major stages are completed in ovaries but rests of the stages are completed in the fallopian tube.
3.	The germinal epithelium lining the seminiferous tubules produces the spermatogonium.	The germinal epithelium present inside the ovaries produces the oogonia.
4.	Supporting cells like sertoli cells and leydig cells are present for nourishment of spermatozoa.	No such cells are present.
5.	It is a continuous process.	Oogenesis starts in the early stages of foetal life and stops till the female reaches puberty. Therefore, it is a discontinuous process.
6.	All the spermatogonium divides to form spermatocytes.	Only some oogonia get the chance to produce oocytes.
7.	Growth phase is comparatively short.	Growth phase persists for a long time. Specifically, the growth phase ends when sperm touch the egg.
8.	Primary spermatocytes divide by meiosis 1 to form two secondary spermatocytes which further produce two spermatids each.	Primary oocytes produce one secondary oocyte and a polar body after meiosis 1 and one ovum and again one polar body after meiosis 2.
9.	Four spermatozoa are produced from a single spermatocyte.	One oocyte produces one ovum and two polar bodies which degenerate thereafter.
10.	Sperms are formed after maturation of spermatozoa and are relatively smaller than spermatozoa.	Eggs are produced from ovum after completion of meiosis and eggs are larger in size than the ovum.
11.	Sperm cells have condensed nucleus i.e. chromosomes are formed.	Eggs possess uncondensed genetic material i.e. genetic material is in the form of chromatin.
12.	Sperms are rich in hydrolytic enzymes and mitochondria.	Ova are rich in a wide range of biochemicals.
13.	Spermatogenesis produces motile gametes having tails.	Oogenesis produces non-motile gametes.

Note: The complete maturation of sperms takes place in the testis as stated above, but the eggs do not mature in the ovary. The ovum enters meiosis 1 and suspends them in metaphase 1 during foetal life. After that ovum starts to release in the oviduct by ovary by the onset of puberty in females, the ovum dies without completing its meiosis if it does not get contact with the sperm. The eggs are produced from primary oocytes only when the sperm touches the ovum, after the contact the egg completes its meiosis and fuses with the sperm in no time.