Question

How does a spermatid differ from a spermatozoa?

Answer 1

Hint: Genetically, spermatid and spermatozoa are the same. But, both are different in appearance under the microscope. Spermatids are formed at the end of meiosis in testis or spermatocytes. They are haploid male gametes, which arise from the division of secondary spermatocytes. To transform into spermatozoa, spermatids must undergo a process called spermiogenesis or metamorphosis, which is the maturation of spermatids into spermatozoa.

Complete answer

Fig: Spermatid and Spermatozoon – Structural Difference
The following table differentiates spermatid from spermatozoa:

Spermatid	Spermatozoa
Spermatid is a rounded, large regular cell with cell organelles in it.	Spermatozoa is needle-like having three distinct parts, namely, head, tail, and middle piece.
Spermatids possess Golgi bodies.	Spermatozoa possess an acrosomal cap and the rest of the Golgi is discarded during metamorphosis.
Spermatid possesses a large and round nucleus.	The nucleus is dehydrated and oblong in spermatozoa.
In spermatids, centrioles are adjacent to the nucleus.	In spermatozoa, one centriole acts like a basal body, as tail filaments arise from the centriole.
Mitochondria are scattered in the spermatid.	A mitochondrial cloud occupies the middle piece in spermatozoa.
Spermatid is non-motile and haploid.	Spermatozoa can move using a flagellar tail.
Spermatid can’t be used as a gamete.	Spermatozoa is a functional gamete, which is used to fertilize an egg cell successfully.

Note:
Spermatid is an immature form of the male gamete, whereas spermatozoa is a mature form of male gamete. While spermatid is found near the walls of seminiferous tubules, spermatozoa are found in the middle of seminiferous tubules. Spermatids are undifferentiated cells, but spermatozoa are differentiated cells. Spermatid is incapable of fertilizing an egg cell, whereas spermatozoa can fertilize an egg cell.