Concept 6 Genes are real things.
![factoid](/images/general/factoid.gif)
![Did you know ?](/images/general/didyouknow.jpg)
Human cells can range in size from red blood cells that are 7 micron (µm) in diameter to nerve cells that may have extensions, called axons, up to 1 meter (m) in length. 1 µm = 10-6 m. The width of a human hair is 100 µm.
![Hmmm...](/images/general/hmmm.jpg)
Did dinosaurs have cells that were the same size as ours? Do we have cells that are the same size as an ant?