DNA is organized in segments on chromosomes called genes. Humans typically have 46 chromosomes arranged in 23 pairs. Genetics plays a key role in answering each of these questions. For humans ...

However, the large chunk that has been sequenced contains versions of several of the same genes that are found in the modern human Y chromosome. In modern humans, a Y chromosome gene called SRY ...

Two X chromosomes mean girl, and an X paired with a Y means boy. For the last 300 million years, this system has worked very ...

Save guides, add subjects and pick up where you left off with your BBC account. The nucleus of each human body cell contains 46 chromosomes. Each chromosome contains about 1000 genes. There is ...

Then one partner acquired a variant gene (SRY) that determines maleness," Graves said to Newsweek. So what happens if the Y disappears? "When humans run out of Y chromosome, they might become ...