The diagram at right shows a simplified DNA fingerprint. Every child receives half of their genes from one parent and the other half of their genes from the other parent. The first column shows the results from electrophoresis from the child. The next two columns show the electrophoresis results from the parents. When scientists analyze DNA fingerprints they are looking for matches in the length of the bands.

Which band sequence from the child match parent 1?

Which band sequence from the child match parent 2?

Notice that band sequence 2 and 3 match parent 1.

Notice that band sequence 1 and 4 match parent 2.

You Try!

1. Study the Mother and Fathers DNA found in the first and last columns below. Could any of the children belong to this mother and father? If so which ones?
   
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   Check Your Answer

   Did you say Child 1 and 3?
   If so you were correct!

   Why could child 2 not belong to these parents? Notice that only sequence 3 and 4 match the parents. In order to be their child all of the sequences would have to match either the mother or the father.

   

   
   
2. Now try some crime scene evidence. The samples are DNA fingerprints of individuals that are suspected or known to have been present at the scene.
   
   
   Do any of the suspect samples match the sample found at the scene? If so who committed the crime?
   
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   Check Your Answer

   Did you say suspect 5?

   Notice that all though all the suspects have some band in common with the sample at the crime scene only suspect 5 is a perfect match.