Watch the Video Click here to watch on YouTube Have you ever seen a zonkey? We typically think of zebras and donkeys as ...

In humans and many other animals, specific chromosomes determine sex. But how did researchers discover these so-called sex chromosomes? Throughout the many observations that led to this conclusion ...

Normally, people have 23 pairs of chromosomes; when someone is born with an extra copy of chromosome 21, it produces the effects of Down syndrome. Most animals can’t have Down syndrome, because their ...

These organisms have independently evolved several important biological characteristics, such as multicellularity, complex life cycles, and sex chromosomes, from plants and animals. Brown algae ...

In humans and many other animal species, sex is determined by specific chromosomes. How did researchers discover these so-called sex chromosomes? The path from the initial discovery of sex ...

In sexual reproduction—the way most life-forms procreate—each parent provides half an offspring’s chromosomes. Over generations, this mating and procreating shuffles the DNA deck ...

Scientists might have figured out why women live longer than men — linking it to having two X chromosomes, which defend ...

Normally, people have 23 pairs of chromosomes; when someone is born with an extra copy of chromosome 21, it produces the effects of Down syndrome. Most animals can’t have Down syndrome ...