dna replication

Telomeres are repeat-DNA caps on chromosome ends that shorten with each cell division. See how telomerase works and what telomere length does not prove.

In 1958, Meselson and Stahl used heavy nitrogen and a centrifuge to prove DNA replicates semiconservatively. Here's exactly how they did it and why it matters.

Learn how DNA replication works, which enzymes drive it, and why the error rate of 1 in a billion matters for your health.