Core Prac 14

Question 1

State the name of the technique for separating out DNA fragments

Answer 1

Gel electrophoresis

Question 2

Describe how to carry out this technique

Answer 2

Pour samples (multiplied by PCR) into wells in gel
Turn on, shorter fragments move further as the DNA is repelled by the negative end and attracted to the positive end

Question 3

Explain why DNA moves to the positive electrode in gel electrophoresis

Answer 3

DNA fragments are slightly negatively charged - opposites attract

Question 4

Explain how the size of the DNA fragment determines the distance it moves

Answer 4

The shorter the fragments, the least likely it is to be caught in the gel, so the further it moves

Question 5

An antelope is found dead in Kruger National Park. The park rangers suspect that the antelope was killed by a cheetah, they take a sample of saliva from the wounds in the antelope.

Answer 5

Compare the saliva DNA to both cheetah and antelope DNA to look for similarities between cheetah and saliva that is not present in the antelope DNA