chromosomes

What defines sex determination? Sex-changing fish enrich the picture.

There are an estimated 37.2 trillion cells in the average adult human body. 37.2 trillion is a staggering number, especially when we remember that we all develop from a single fertilized egg cell. So how does one cell become 37.2 trillion cells? Through…

by Katherine J. Wu figures by Daniel Utter Let’s talk about sex. Seriously. Not intercourse, though – more about how genetic sex is programmed during development. Sexual identity has been in the news often lately, and unsurprisingly so: the past few…