Genetic fingerprinting

Question 1

What is genetic fingerprinting?

Answer 1

The number of times a sequence is repeated at different places in the genome can be compared between individuals

Question 2

What are VNTR’s also known as?

Answer 2

Short tandem repeats

Question 3

What are short tandem repeats?

Answer 3

Base sequences that don’t code for a protein and repeat over and over

Question 4

What is the first step in producing a genetic fingerprint?

Answer 4

PCR is used to produce multiple copies of the DNA fragments

Question 5

What role do primers play in genetic fingerprinting?

Answer 5

They bind to either side of the repeats and the whole repeat is amplified

Question 6

What does the amplifying of the repeats produce?

Answer 6

Different length fragments

Question 7

What is attached to the primer?

Answer 7

Fluorescent tags

Question 8

What does the DNA mixture that is used in gel electrophoresis contain?

Answer 8

Different lengths of DNA fragments

Question 9

Where are the different length fragments added into?

Answer 9

The wells on the plate of agarose gel

Question 10

What is the agarose gel placed in and why?

Answer 10

Buffer solution to conduct electricity

Question 11

What makes up a control DNA ladder and why is it added to the agarose gel?

Answer 11

Known lengths of DNA fragments

As a comparison to work out the unknown lengths of the sample DNA fragments

Question 12

What is sent around the agarose gel?

Answer 12

An electrical current

Question 13

Where is the positive anode on the agarose gel? Why is this the case?

Answer 13

At the opposite side to the wells

So the DNA fragments (negative) move towards the positive charge

Question 14

Which fragments move the furthest?

Answer 14

The lightest, shortest fragments

Question 15

Which fragments move the least distance?

Answer 15

The heaviest, longest fragments

Question 16

How is a genetic fingerprint analysed?

Answer 16

Placed under UV light

Makes the DNA fragments visible

Question 17

How are genetic fingerprints used in genetic relationships?

Answer 17

• Individuals inherit short tandem repeats from parents
• If two fingerprints are a close match, then they are closely related
• Used in paternity tests

Question 18

How are genetic fingerprints used to look at genetic variability within a population?

Answer 18

• The greater the number of bands that don’t match between two fingerprints, the more genetically different individuals are
• The more the number of repeats varies at several places, the greater the genetic variability within a population

Question 19

How are genetic fingerprints used in forensic science?

Answer 19

• Used to compare DNA samples from the crime scene with the DNA of any suspects
• The DNA is obtained from each sample and replicated using PCR
• Gel electrophoresis then used

Question 20

How are genetic fingerprints used in medical diagnosis?

Answer 20

• A genetic fingerprint, in medical diagnosis, can refer to a unique pattern of several alleles
• You can diagnose genetic disorders and cancer
• Identifies a broader, altered genetic pattern

Question 21

How are genetic fingerprints used in animal and plant breeding?

Answer 21

• Used to prevent inbreeding which decreases the gene pool
• Inbreeding also leads to a higher risk of genetic disorder and produces health, productivity and reproductive problems
• Identify the least related individuals