I believe they are known as "master control genes" and develop the foetus in areas such as head, arms, legs, digestive systems, and their organs' many shape's and sizes, etc. An enzyme known as hedgehog is responsible for activating these genes and their development. However, this is rather old information (a documentary around 6 years … Read more

The appearance of genitalia on a foetus in all mammals is female until male hormone (testosterone) becomes active in normal male foetus development; at which point the flaps of skin that would usually form the vaginal flaps become testicles and the clitoris the penis.    The only way a genetic female would have testicles would … Read more

You need to describe the lump's appearance to get any meaningful information as  with the brief description above, it could almost be anything: This may not be the cause of your problem but it rang a bell with me, A friend of mine experienced this when he was in his teens, the lump turned out to … Read more