The formation of primary spermatocytes (a process known as spermatocytogenesis) begins in humans when a male is sexually matured at puberty, around the age of 10 through 14.

How primary spermatocytes are formed?

Spermatogenesis begins with a diploid spermatogonium in the seminiferous tubules, which divides mitotically to produce two diploid primary spermatocytes. The primary spermatocyte then undergoes meiosis I to produce two haploid secondary spermatocytes.

Do primary spermatocytes undergo mitosis?

Note that the primary spermatocytes are the result of a mitotic division and are therefore diploid. At the end of the first meiotic division, each primary spermatocyte will produce 2 secondary spermatocytes.