Spermatogenesis is the process by which haploid spermatozoa develop from the diploid spermatogonial germ cells in the seminiferous tubules of the testicle.
This process starts with the mitotic division of the spermatogonial germ cells located close to the basement membrane of the tubules
The mitotic division of these produces two types of cells.
Type A cells replenish the stem cells.
Type B cells differentiate into primary spermatocytes.