Describe the process of spermatogenesis with a labelled diagram.

(N/A) Spermatogenesis is the process by which immature male germ cells (spermatogonia) produce sperms in the testes,beginning at puberty.
Spermatogenesis involves two main stages: $(1)$ Formation of spermatids and $(2)$ Spermiogenesis.
$(1)$ Formation of spermatids: This process occurs in three phases:
$(i)$ Multiplication phase: Spermatogonia present on the inner wall of seminiferous tubules multiply by mitotic division. Each spermatogonium is diploid $(2n)$ and contains $46$ chromosomes.
(ii) Growth phase: Each spermatogonium increases in size by accumulating nutritive material and is now called a primary spermatocyte. It receives nutrition from Sertoli cells.
(iii) Maturation phase: Primary spermatocytes undergo meiosis. The first meiotic division (meiosis $I$) results in two equal,haploid cells called secondary spermatocytes $(n)$,each with $23$ chromosomes. These then undergo the second meiotic division (meiosis $II$) to produce four equal,haploid spermatids.
$(2)$ Spermiogenesis: The transformation of non-motile spermatids into mature,motile spermatozoa is called spermiogenesis.
After spermiogenesis,sperm heads become embedded in the Sertoli cells and are finally released from the seminiferous tubules by a process called spermiation.