Describe how genetic fingerprinting is carried out? (example of 6-mark question)

Every individual's DNA sequence is different and genetic fingerprinting can be used to distinguish individuals based on their unique DNA sequence. To begin, DNA needs to be extracted from a sample, which could be either blood, skin or hair follicle. DNA is cut into segments using restriction endonucleases whilst also leaving intact micro-satellites. DNA probes complementary to micro-satellites are added. The mixture pipetted into wells on gel and an electric current is passed through enabling the separation of DNA fragments by gel electrophoresis. X-ray film is used to identify the areas with the probe and therefore identify the unique pattern of fragments.

FH

Related Biology A Level answers

All answers ▸

How are signals transmitted across the synaptic cleft?


Albumin (a globular protein) is a solute found in blood plasma. In liver disease, people cannot produce sufficient amounts of albumin. Describe and explain how this change would affect red blood cells.


What is meant by the term "tertiary structure" of a protein? Describe the forms of bonding that could be involved.


How does the body increase heart rate in response to exercise?