A person can be identified by their DNA. Each person has a different  DNA pattern. Police also can use DNA to find out what  happened at a crime scene. Did you know that in each cell in a person has identical DNA.

   

	A very interesting story goes with this  picture. There was a woman, a man and their two sons. They  sent in some of their own DNA to a lab. When they got the DNA results back they found out their second son was missing a part in his genetic code.  It also was a coincidence that he had trouble speaking and the missing DNA .
	This is how you blot DNA.  You can look at the DNA blot made from two different cells, such as DNA from the hair and blood of the same person.   A scientist can see that the DNA blots are the same.  They should be the same because the DNA came from the same person.
	You can study someone's DNA pattern by looking at the shape of chromosomes.  The chromosomes are stained so that bands or stripes show up.  In people, there are 23 pairs of chromosomes that doctors or scientists can study. A man's genetic code has x and y chromosomes.
	A womens genetic code has x and x chromosomes.

Bibliography

from Google images search:
          www.the_scientist.com/.../lewis_p1_990412.html
          www.cell biology.wusll.edu/faculty/huettner/nfscl.html
          www.employees.csbsju.edu/.../list_of-figures.htm
          employees.csbsju.edu/.../dna/chromosomes.gif