AQA A-LEVEL BIOLOGY GENETICS
REVISION PAPERS 2023 WITH CORRECT
QUESTIONS AND ANSWERS
Name two ways meiosis produces genetic variation. (2) (Correct Answers) - formation of
chiasmata
- independent segregation of homologous chromosomes
Use your knowledge of enzyme action to explain why DNA polymerase acts in opposite
directions when replicating DNA. (4) (Correct Answers) - DNA has anti-parallel strands
- Nucleotides aligned differently
- Enzymes have active sites with specific shapes
- Only the phosphate end of the developing strand can bind with the active site of DNA
polymerase
The scientists obtained DNA from otters that were alive before hunting started.
Suggest one source of this DNA. (1) (Correct Answers) Bone/skin/preserved remains
What can you conclude about the effect of hunting on genetic diversity in otters? (2)
(Correct Answers) - Hunting reduced population size so only a few alleles left
- Interbreeding would occur amongst the population
Other than hunting, suggest two reasons why populations might show very low levels of
genetic diversity. (2) (Correct Answers) - Population may be small (genetic bottleneck)
- Interbreeding
REVISION PAPERS 2023 WITH CORRECT
QUESTIONS AND ANSWERS
Name two ways meiosis produces genetic variation. (2) (Correct Answers) - formation of
chiasmata
- independent segregation of homologous chromosomes
Use your knowledge of enzyme action to explain why DNA polymerase acts in opposite
directions when replicating DNA. (4) (Correct Answers) - DNA has anti-parallel strands
- Nucleotides aligned differently
- Enzymes have active sites with specific shapes
- Only the phosphate end of the developing strand can bind with the active site of DNA
polymerase
The scientists obtained DNA from otters that were alive before hunting started.
Suggest one source of this DNA. (1) (Correct Answers) Bone/skin/preserved remains
What can you conclude about the effect of hunting on genetic diversity in otters? (2)
(Correct Answers) - Hunting reduced population size so only a few alleles left
- Interbreeding would occur amongst the population
Other than hunting, suggest two reasons why populations might show very low levels of
genetic diversity. (2) (Correct Answers) - Population may be small (genetic bottleneck)
- Interbreeding
