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You have the ability to pick up small objects because you have a very special thumb. It can move in many directions. We call this type of thumb an oposable thumb. To aide in helping you pick things up, nature has put small grippers in your fingers. The grippers have high and low points on them. The grippers form patterns and designs. We call these designs
fingerprints. |
Close up of a finger tip showing |
The HIGH points are called hills, while the LOW points are called valleys |
The edges of the penny are higher Your fingerprint is like this too. The hills or ridges stick up and get ink on them. The hills and ridges leave a mark on paper as does the outer edge of a penny. The white lines on a fingerprint are the valleys or spaces between the hills. These areas never got ink on them because they were lower and never reached the ink pad. |
EXTRA CREDIT |
1) Define these terms (Look in a dictionary)
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2) Why does ink not get into the valleys on your finger? 3) How do the prints on your fingers help you? | |