Cells Alive How Big interactive - see size comparisons of a human hair, a dust mite, pollen, bacteria, and viruses

Cells Alive!


The Cells Alive!  website is a great resource for biology teachers and home educators covering cell biology.

One of the most unique features of this site — which can be used for elementary through college students — is the How Big? interactive Zoom in to see the relative sizes of a pin head, a human hair, a dust mite, and various bacteria and viruses.  This really gives people of all ages a solid understanding of just how small these microscopic objects are!  Measurements are provided in millimeters, then micrometers and finally nanometers.

This site also features a Cell Gallery, interactive Cell Models with links to more information about each structure, and various online puzzles and quizzes.

There are 4 sections on the Cells Alive! website, each with links to their various interactive features:

While much of the details on this site can really only be useful to high school or college level students, a few animations and interactives are helpful for even young children – like the How Big? interactive mentioned above.


If you use the Cells Alive! website — or would like to recommend a similar resource — please leave a little feedback below – thanks!


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