7.1.3 - DNA profiling

Question 1

What are mini satellites?

Answer 1

10-100 base sequence that is repeated 50 to hundreds of times.

Question 2

What are micro satellites?

Answer 2

2-6 bases that are repeated 5 to 100 times

Question 3

Are satellites of DNA found in the coding or non-coding sections of DNA?

Answer 3

Non-coding

Question 4

How do you make a DNA profile?

Answer 4

DNA is cut into pieces using restriction enzymes
Electrical current separates the DNA pieces in a gel
Separated DNA pieces are transported to a membrane
Chemicals make the bands visible on the membrane

Question 5

What is the purpose of DNA profiling?

Answer 5

The process of analysing DNA variations for the purpose of identification

Question 6

What happens to the satellites in gel electrophoresis with the most repeats?

Answer 6

They don’t move through the gel as far as other fragments

Question 7

What are genetic markers?

Answer 7

Regions of DNA which vary between individuals

Question 8

Describe Southern blotting.

Answer 8

An alkaline buffer solution is added to the gel after electrophoresis.
A nylon filter paper is placed over it
The dry absorbent material is used to draw the solution containing DNA fragments from the gel to the filter, leaving blots attached to the filter.

Question 9

What are gene probes?

Answer 9

Short DNA sequences that are complementary to sequences that are being sought.
Added to filter after southern blotting process and they bind with the complementary DNA strands - this is hybridisation.
Each probe is labelled with a fluorescent molecule.