Kids won’t need beakers and microscopes for these biology experiments—they just need themselves! Each of these five experiments lets children discover how a human body system works.

About 98% of the atoms in the human body are renewed each year. This surprising fact is discussed by Dr. Paul C. Aebersold of Oak Ridge in the latest Annual Report of the Smithsonian Institution.

But we’ve learned quite a lot of fascinating things about the human body this year, too, in relation to topics ranging from eye and uterus transplants to vitamin D levels and aging. Here are a ...