Q.Mention the differences between spermiogenesis and spermatogenesis.

Spermatogenesis is the complete sperm-formation process from spermatogonium to spermatid; spermiogenesis is its concluding sub-stage in which spermatids are remodelled into functional, motile sperm.

Spermatogenesis begins with diploid spermatogonia in the seminiferous tubules, which multiply by mitosis; some enter meiosis as primary spermatocytes, undergo meiosis I to form secondary spermatocytes, and meiosis II to form haploid, round, non-motile spermatids -- this entire multi-step sequence (spermatogonium -> primary spermatocyte -> secondary spermatocyte -> spermatid) is spermatogenesis. Spermiogenesis, by contrast, refers specifically to the last phase of this overall process: the structural transformation of the round, immotile spermatids into elongated, streamlined, motile spermatozoa, involving condensation and elongation of the nucleus, formation of the acrosome from the Golgi apparatus (containing hydrolytic enzymes for penetrating the egg), development of the flagellum (tail) from the centriole for motility, and …