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Reproductive System Development (view source)
Revision as of 08:26, 22 August 2011
, 08:26, 22 August 2011→Sex Determination in Mammals
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Fetal development in mammals occurs in a highly hormonal environment with relatively high concentrations of oestrogens and progesterone and therefore during the early stages of embryonic development the gonads must produce testosterone and other developmental signalling molecules in order for the testes to develop. If no testosterone is produced, the reproductive organs will take on female characteristics as a default. Abnormalities can occur if the gonads in a genetic male do not produce sufficient levels of testosterone.
Fetal development in mammals occurs in a highly hormonal environment with relatively high concentrations of oestrogens and progesterone and therefore during the early stages of embryonic development the gonads must produce testosterone and other developmental signalling molecules in order for the testes to develop. If no testosterone is produced, the reproductive organs will take on female characteristics as a default. Abnormalities can occur if the gonads in a genetic male do not produce sufficient levels of testosterone.
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Genital development under testosterone therefore induces the penis and scrotum to develop. Testosterone is converted to '''dihydrotestosterone''' which is the signalling molecule responsible for the external appearence of the penis and scrotum. An absence of testosterone results in the development of the clitoris, labia and vaginal opening.
==Sex Determination in Birds==
==Sex Determination in Birds==