In a developing fetus, what influences whether it is going to become male or female? What influences the cells to start building male or female organs?

Question

In a developing fetus, what influences whether it is going to become male or female? What influences the cells to start building male or female organs?

In: 274

Answer 1

All start out female for the first several weeks. It is only later in the pregnancy that hormones are turned on/off to determine gender.

Sexual attraction and sexual identity come later, too. The same bits of tissue in the initially female baby will turn ovary into testicles, the clitoris into a penis, and so on. Or in the absence of those hormones, they remain in the initial female form.

And to make things even more (potentially) confusing, the timing and duration of hormones affecting each of the three variables (sex, identity, and attraction) can occasionally vary from “normal” and you get a person who is gay/lesbian and/or transgender or another combination all together.