21 - Manipulating Genomes

Question 1

Genome (21.1)

Answer 1

All genetic material in an organism

Question 2

Introns + Exons

Answer 2

Introns - non coding regions of DNA
Exons - coding DNA

Question 3

Satellite DNA

Answer 3

Short sequences of DNA within introns, exons and telomeres that are repeated many times

Question 4

Mini satellite / variable number tandem repeats (VNTR’s)

Answer 4

• sequence of 20-50 base pairs
• repeated 50-several hundred times
• occur at more than 1000 locations in human genome

Question 5

Microsatellite / short tandem repeats (STR’s)

Answer 5

• 2-4 bases
• repeated 5-15 times

Question 6

PCR (polymerase chain reaction)

Answer 6

1) DNA sample, excess of 4 bases, small primer DNA sequences and DNA polymerase added to vial
2) Temp increased to 90/95 for 30 secs, denatures DNA breaks hydrogen bonds
3) Temp decreased to 55/60, primers anneal to ends of DNA strands
4) Temp increased to 72/75 for at least 1 minute - optimum temp for DNA polymerase, bases added to primer, builds up complementary base strands of DNA, Taq polymerase used.

Question 7

DNA profiling

Answer 7

1) Extracting - DNA extracted and amplified using PCR
2) Digestion - DNA cut using restriction endonucleases, cut DNA at specific points - restriction site, make one cut through each DNA strand
3) Separation - gel electrophoresis, particles move through gel medium with electric current, single stranded DNA then transferred via southern blotting
4) Hybridisation -