Question

What is spermiation?

Answer 1

Hint: Spermiation is not a part of spermatogenesis but it is a process that follows spermatogenesis. Spermatogenesis is defined as the process by which sperms are produced.

Complete answer:
Spermiation is the release of mature sperms from Sertoli cells to seminiferous tubules before they move into the epididymis.

Additional information:
Sperms are male gametes that fertilize with the ovum(female gametes) to form a zygote. Sperms are produced in the male testis. Sperms are produced by a process known as spermatogenesis.
The stages of sperm formation include the following stages:
> Multiplication phase: Germ cell undergoes mitotic division to form two daughter cells. Germ cells are diploid so daughter cells are diploid as mitosis takes place.
These daughter cells divide further to form spermatogonia by mitosis. They are diploid.one-half of the spermatogonia act as stem cells (they will undergo multiplication to form more spermatogonia) and are known as Type A spermatogonia. Other half participate in the next stages known as Type B spermatogonia.

> Growth phase: Type B spermatogonia grow larger in size due to the accumulation of nutritive material. Now it is called primary spermatocyte. This is diploid.

> Maturation phase: Primary spermatocytes undergo meiosis. Meiosis-1 being reductional division forms two haploid secondary spermatocyte cells. Meiosis 2 being equational division, forms 4 haploid spermatids.
Spermatids change into motile sperms by changes in structure. This process is known as spermiogenesis.
During the development of sperms, sperms remain embedded into the folds of Sertoli cells. They will be released into the lumen of seminiferous tubules only when they are mature. This is known as spermiation.

Note: Spermiation is different from spermatogenesis and spermiogenesis. All three terms- spermiation, spermatogenesis, and spermiogenesis are very different from each other and should not be confused with each other.