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Title: A2 Level (Unit 4) DNA, PCR, Gel Electrophoresis Question and Answers
Description: A2 Level Biology Unit 4 -The Natural Environment and Species Survival DNA, PCR and Gel Electrophoresis section. Really easy, fast and effective revision resource. Questions and Answers!
Description: A2 Level Biology Unit 4 -The Natural Environment and Species Survival DNA, PCR and Gel Electrophoresis section. Really easy, fast and effective revision resource. Questions and Answers!
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Unit 4 – The Natural Environment and Species Survival
DNA
What are the non-coding blocks in DNA called?
-Introns
What are the coding regions called?
-Exons
What are the sequences of repeated bases known as?
-Short tandem repeats (STR’s)
How is DNA obtained?
-The tissue sample is broken down in a buffer solution that includes salt and detergent to
disrupt the cell membranes
...
-Protease enzymes are incubated with the suspension to remove proteins
...
-Several stages of washing the DNA in a buffer solution then follow
...
-These enzymes are found naturally in bacteria where their function is to cut up invading
viral DNA
...
What are DNA primers?
-They are short DNA sequences complementary to the DNA adjacent to the STR
...
-The forensic sample is placed in a reaction tube with DNA polymerase, DNA primers and
nucleotides
...
What is the first temperature and what does this do?
-95c
-This separates the DNA into two strands
What is the second temperature and what does this do?
-55c
-This optimises prime binding to the target DNA sequence in the sample
...
What is the third temperature and what does this do?
-70c
-This final temperature is the optimum temperature for the heat-stable polymerase
...
-The STR repeated sequence and DNA adjacent is replicated
...
-The gel is submerged in a buffer solution and connected to electrodes that produce a
potential difference across the gel
...
-Smaller fragments with smaller numbers of repeat sequences travel faster
...
What are the fragment lengths measured in?
-Base pairs
Title: A2 Level (Unit 4) DNA, PCR, Gel Electrophoresis Question and Answers
Description: A2 Level Biology Unit 4 -The Natural Environment and Species Survival DNA, PCR and Gel Electrophoresis section. Really easy, fast and effective revision resource. Questions and Answers!
Description: A2 Level Biology Unit 4 -The Natural Environment and Species Survival DNA, PCR and Gel Electrophoresis section. Really easy, fast and effective revision resource. Questions and Answers!