The male and female nuclei go on to form the two separate halves of the same bird. In this scenario, the bird can be either sex on either side, depending on how the female's chromosomes are split ...

How is sex determined using chromosomes? You might remember learning in high school biology that all the genetic information in the human body is packaged into 23 pairs of chromosomes.

For the first time scientists have created two lines of human cells that are identical aside from their sex chromosomes: one has XX chromosomes, and one has XY. This unique set of cells could help ...

Intersex people are born with genitals, chromosomes, or internal reproductive organs that don't fit typical male or female patterns and may not match their sex assigned at birth. Find out more.

What Makes Male Calicos So Uncommon? Genetics are the reason calico tomcats are so rare. Coat color in cats is typically a sex-linked trait—in other words, color is coded into certain chromosomes.

In humans, biological sex is usually determined by our chromosomes. Those born female typically have two X chromosomes, while those born male tend to have an X and a Y chromosome. Birds are the ...