A-LEVEL BIOLOGY EXAM PAPER QUESTIONS
WITH COMPLETE SOLUTIONS
How is relative risk defined?
The relative risk is estimated based on the observations of non-
exposed patients
The relative risk is estimated based on the observations of exposed
patients
The relative risk is defined as the ratio of the probabilities being
affected among exposed and non-exposed
The relative risk is defined as the ratio of exposed and non-exposed
patients numbers
All of the answers
1. What is the role of BrdU in DNA replication?
It acts as a primer for DNA synthesis
It replaces thymidine in newly synthesized DNA
It initiates the unwinding of the DNA helix
It stabilizes the DNA double helix
2. If a farmer decides to replant hedges on a portion of their land, what might
be a long-term economic consequence of this decision?
Increased crop yield due to better soil health
Higher income from diversified crops
Decreased overall crop production leading to lower income
Improved market prices for crops due to scarcity
,3. Explain why genetic differences might prevent Ulva prolifera and Ulva
lactuca from successfully reproducing.
Genetic differences can lead to hybrid vigor.
Genetic differences may result in incompatible gametes.
Genetic differences enhance adaptability to environments.
Genetic differences have no effect on reproduction.
4. Explain how the water potential of a sodium chloride solution is related to its
concentration. What does a water potential of −1.95 MPa indicate about the
solution's concentration?
It indicates a low concentration of solutes.
It indicates a high concentration of solutes.
It indicates isotonic conditions.
It indicates a neutral pH.
5. If a mutation occurred in the proteins of the HIV envelope, what potential
impact could this have on the virus's ability to infect host cells?
It would increase the virus's replication rate.
It could hinder the virus's ability to attach to host cells.
It would enhance the immune response against the virus.
It would have no effect on the virus's infectivity.
6. What does a P value of 0.03 indicate in hypothesis testing?
The null hypothesis is accepted
There is no significant effect
, The null hypothesis can be rejected
The results are inconclusive
7. Which of the following methods can be used to ensure that an index of
biodiversity is representative of a habitat?
Sampling from a single location
Conducting surveys at different times
Using only one type of sampling technique
Ignoring seasonal changes
8. If relative risk (RR) = 1, it means there is _________ _.
greater risk in the treatment group
lower risk in the treatment group
no difference in risk between the groups
9. A researcher is studying the dietary fiber intake of a population over a year.
Which method would be most appropriate for this study, and why?
24-hour recall, because it provides detailed daily intake.
Food frequency questionnaire, because it assesses intake over a
longer period.
Food diary, because it is the most accurate method.
Interviews, because they allow for personal dietary preferences.
10. Explain how reduced turgor pressure due to low water availability can impact
plant growth.
It increases photosynthesis rates
WITH COMPLETE SOLUTIONS
How is relative risk defined?
The relative risk is estimated based on the observations of non-
exposed patients
The relative risk is estimated based on the observations of exposed
patients
The relative risk is defined as the ratio of the probabilities being
affected among exposed and non-exposed
The relative risk is defined as the ratio of exposed and non-exposed
patients numbers
All of the answers
1. What is the role of BrdU in DNA replication?
It acts as a primer for DNA synthesis
It replaces thymidine in newly synthesized DNA
It initiates the unwinding of the DNA helix
It stabilizes the DNA double helix
2. If a farmer decides to replant hedges on a portion of their land, what might
be a long-term economic consequence of this decision?
Increased crop yield due to better soil health
Higher income from diversified crops
Decreased overall crop production leading to lower income
Improved market prices for crops due to scarcity
,3. Explain why genetic differences might prevent Ulva prolifera and Ulva
lactuca from successfully reproducing.
Genetic differences can lead to hybrid vigor.
Genetic differences may result in incompatible gametes.
Genetic differences enhance adaptability to environments.
Genetic differences have no effect on reproduction.
4. Explain how the water potential of a sodium chloride solution is related to its
concentration. What does a water potential of −1.95 MPa indicate about the
solution's concentration?
It indicates a low concentration of solutes.
It indicates a high concentration of solutes.
It indicates isotonic conditions.
It indicates a neutral pH.
5. If a mutation occurred in the proteins of the HIV envelope, what potential
impact could this have on the virus's ability to infect host cells?
It would increase the virus's replication rate.
It could hinder the virus's ability to attach to host cells.
It would enhance the immune response against the virus.
It would have no effect on the virus's infectivity.
6. What does a P value of 0.03 indicate in hypothesis testing?
The null hypothesis is accepted
There is no significant effect
, The null hypothesis can be rejected
The results are inconclusive
7. Which of the following methods can be used to ensure that an index of
biodiversity is representative of a habitat?
Sampling from a single location
Conducting surveys at different times
Using only one type of sampling technique
Ignoring seasonal changes
8. If relative risk (RR) = 1, it means there is _________ _.
greater risk in the treatment group
lower risk in the treatment group
no difference in risk between the groups
9. A researcher is studying the dietary fiber intake of a population over a year.
Which method would be most appropriate for this study, and why?
24-hour recall, because it provides detailed daily intake.
Food frequency questionnaire, because it assesses intake over a
longer period.
Food diary, because it is the most accurate method.
Interviews, because they allow for personal dietary preferences.
10. Explain how reduced turgor pressure due to low water availability can impact
plant growth.
It increases photosynthesis rates
