Q.Define spermiogenesis.

[!TLDR]

Spermiogenesis is the transformation of a rounded, non-motile spermatid into a streamlined, motile spermatozoon.

[!ANSWER]

Spermiogenesis is the process by which a haploid spermatid is remodelled into a mature spermatozoon (acrosome-capped head, mitochondrial middle piece, flagellar tail).

Once meiosis is complete, the resulting spermatids look nothing like a mature sperm -- they are simply small rounded cells. Spermiogenesis is the subsequent structural remodelling in which the Golgi apparatus forms the acrosomal cap, the nucleus condenses to form the sperm head, mitochondria arrange into a helical sheath forming the middle piece around a newly formed flagellum, and surplus cytoplasm is shed, producing the final streamlined, motile spermatozoon.

[!ANSWER]

Spermiogenesis is the process by which a haploid spermatid is remodelled into a mature spermatozoon (acrosome-capped head, mitochondrial middle piece, flagellar tail).

Recall that spermiogenesis is a structural transformation stage (no further division), occurring after meiosis is already complete, distinct from the earlier meiotic divisions themselves.

Confusing spermiogenesis (post-meiotic structural remodelling of the spermatid) with spermatogenesis (the entire process from spermatogonium to sperm) -- spermiogenesis is only the final transformation stage within the larger process.