|MadSci Network: Development|
Todd: Boys are born with the cells which will make sperm in a very undeveloped stage. These cells found in the testes are called spermatogonia and they will eventually produce all the sperm cells the man will have. Around the time of puberty (http://www.youthshakers.org/sexualhealth/youngmen/), the spermatogonia will begin to change and start the process of sperm development called spermatogenesis (http://www.gpnotebook.co.uk/cache/892665869.htm). This usually begins sometime around 10-12 years of age and is fully functional by the age of 14-16 years. As the boy continues to mature, the number of sperm cells increases from few at 10-12 with a full complement of sperm cells by age 16. It is possible for very young boys to father children as the number of sperm in sufficient at puberty to fertilize oocytes. I hope this helps!! David Mallory, PhD Marshall University Huntington, WV USA
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