DNA fingerprinting Flashcards Preview

Biology; Detection > DNA fingerprinting > Flashcards

Flashcards in DNA fingerprinting Deck (9)
Loading flashcards...

What can DNA fingerprinting be used for?

To match a suspect to a crime scene


What is the exception to 'everyone's DNA is different' and why?

Identical twins have the same DNA because they are formed when one fertilized egg splits in to two embryos at the early stages of development.


Define DNA fingerprinting ( or DNA profiling )

DNA fingerprinting; is the analysis of DNA from body samples, to identify individuals. As your DNA is unique it is possible to work out if the DNA has come from you, or from someone else.


Where is DNA found?

In the nucleus of all body cells (except Red Blood Cells as they have no nucleus).


Therefore which cells can you extract DNA from?

All body cells that contain DNA (not RED blood cells)


Where is the most common place to take DNA from?

From your blood (white blood cells), hair or cells from the inside of your cheek.


How do you make a DNA fingerprint? (6)

1. DNA is extracted from cells
2.Enzymes are used to cut the DNA into short fragments
3.Samples of the DNA are inserted into a well, ( a small dent ) in a gel 4.An electric current is passed through the gel, this makes the fragments move
5.The fragments move different distances depending on their size 6.The pattern produced is the person's fingerprint, it looks a bit like a barcode


To find out weather someone was at the scene of a crime you comapre their DNA fingerprint to the on that was on the crime scene.

The 3 suspects (right) are compared to the fingerprnts found on the crime scene.

Which matches?



What are the other uses of DNA fingerprinting?

  • Maternity and Paternity tests- by comparing fragments of DNA  you can see whose mother and father the child's is. The child will have sections thatt match the mother and others that match the father.
  • Genetic councelling- people wishing to have a child can be tested to see if they carry a genetically inherited disease. This allows them to ake an informed choice weather or not to have a baby.
  • Identification and treatment of genetic disorders- the tratment of some genetic disorsders is more successful when they are iddentified earlier in life.