You can’t see them, but they’re everywhere even inside Bill Nye. This is not science fiction, it’s the science of cells.

All things that live are made from cells. You can’t see them, but every part of your body, including everything inside your body, is made from cells. Cells eat, they grow, and they make more of themselves (what scientists call replicate).

There are millions of different types of cells. Dog cells are different from fish cells. Bird cells are different from your cells. And inside your body, there are many different cells, each one doing a different job to keep your body going.

Cells may be tiny, but without them, we’d be nothing.

The Big Idea

  • All living things are made out of cells
  • Different types of cells have different jobs
  • The arrangement of cells gives us the wide variety of life forms found on Earth.

Did You Know That?

  • There are between 50 and 75 trillion cells in your body?
  • Human red blood cells live for around 120 days, but stomach cells only last 2 days?
  • The biggest single cell you might ever see is the ostrich egg?

Books of Science!

  • “Cells Are Us” by Fran Balkwill. Published by Carolrhoda Books, 1993.
  • “Cells” by George S. Fichter. Published by Franklin Watts, 1986.