genetic fingerprinting

Question 1

variable number tandem repeats VNTR

Answer 1

base sequences that don’t code for proteins and repeat next to each other over and over
number of times they are repeated differs from person to person - length differs

Question 2

genetic fingerprinting

Answer 2

comparing between individuals the number of times a sequence is repeated at different places in their genome

(probability of 2 individuals being same very low)

Question 3

preparing DNA for electrophoresis

separates DNA fragments to make genetic fingerprint

Answer 3

1. sample of DNA obtained e.g. blood
2. PCR used to make many copies of the areas of DNA that contain VNTR’s
3. primers are used that bind to either side of the repeats - whole repeat amplified
4. DNA fragments where length corresponds to number of repeats
5. a fluorescent tag added to all DNA fragments so can be viewed under UV light

Question 4

electrophoresis

separates DNA fragments to make genetic fingerprint

Answer 4

1. DNA mixture placed in a well in a slag of gel and covered in buffer solution that conducts electricity
2. electrical current passed through gel. DNA fragments negativley charged. move towards positive electrode
3. small DNA fragments travel faster and travel further through the gel - DNA fragments separate according to size
4. veiwed as bands under UV light - genetic fingerprint
5. 2 genetic fingerprints can be compared

Question 5

genetic fingerprinting

determining relationships

Answer 5

inherit VNTR sequence from parents
1/2 of sequences come from each parent
more bands on a genetic fingerprint that match = more closely related
e.g. paternity test

Question 6

genetic fingerprinting

determining genetic variability within a population

Answer 6

greater number of bands that don’t match = more genetically different

Question 7

genetic fingerprinting

forensic science

Answer 7

1. DNA isolated
2. sample replicated using PCR
3. PCR products run on electrophoresis gel
4. genetic fingerprint compared to see if a match
5. sample matches = links person to crime scene

Question 8

genetic fingerprinting

medical diagnosis

Answer 8

1. genetic fingerprint can refer to unique pattern of several alleles
2. can be used to diagnose genetic disorders and cancer - useful when specific mutation isnt known or where several mutations could have caused genetic disorder - identifies broader altered genetic pattern

Question 9

genetic fingerprinting

animal and plant breeding

Answer 9

1. prevents interbreeding which decreases the gene pool
2. interbreeding can lead to increased risk of genetic disorders, leading to health productivity and reproduction problems.
3. can be used to identify how closely related individuals are - more closely related more similar genetic fingerprint
4. least related individuals bread together