<P> For humans , the entire process of spermatogenesis is variously estimated as taking 74 days ( according to tritium - labelled biopsies ) and approximately 120 days ( according to DNA clock measurements ) . Including the transport on ductal system , it takes 3 months . Testes produce 200 to 300 million spermatozoa daily . However , only about half or 100 million of these become viable sperm . </P>
<P> For humans , the entire process of spermatogenesis is variously estimated as taking 74 days ( according to tritium - labelled biopsies ) and approximately 120 days ( according to DNA clock measurements ) . Including the transport on ductal system , it takes 3 months . Testes produce 200 to 300 million spermatozoa daily . However , only about half or 100 million of these become viable sperm . </P>
how often does spermatogeneis -- the production of sperm -- occur
how often does spermatogeneis -- the production of sperm -- occur
74 days
74 days