A recent Trump executive order defines sex based on gamete size. But the order oversimplifies genetics, hormones and reproductive biology.

How do behavior, morphology and physiology act in concert to improve a male's reproductive success - and why is there so much variation among outcomes within and between species? Aa Aa Aa ...

Sex is widely understood to refer to a label assigned at birth based on one’s anatomy that ... the size of reproductive cells, hormone levels, internal organs or genitals.” ...

Male and female reproductive systems allow human reproduction ... giving insight to the human body and its capabilities. BBC Teach has thousands of free, curriculum-linked resources to help ...

President Trump issued an executive order declaring that the U.S. government would only recognize a person’s sex assigned at birth.

Their analysis of male reproductive ... However, despite their reproductive attempts, they were completely sterile. At the same time, the female reproductive organs associated with sexual ...