AQA A LEVEL BIOLOGY EXAM 200 ACTUAL QUESTIONS
AND CORRECT ANSWERS WITH RATIONALE LATEST 2026
ALREADY GRADED A+
This AQA A-Level Biology examination comprehensively assesses
understanding of biological principles across diverse topics. It covers
biological molecules, including carbohydrates, proteins, and nucleic acids,
alongside cellular processes such as photosynthesis, respiration, and protein
synthesis. The exam evaluates genetics, including inheritance patterns,
mutations, and gene expression. Organismal biology is tested through gas
exchange, transport systems (xylem, phloem, circulatory), and the immune
response. Ecological principles, energy transfer, nutrient cycles, and
succession are also assessed. Candidates must demonstrate knowledge of
practical techniques, data analysis, and apply biological concepts to
unfamiliar scenarios, requiring both recall and critical thinking skills.
1. Give two ways in which plants use the molecules produced during
photosynthesis.
A) For respiration and to produce cellulose
B) For respiration and to produce amino acids
C) For active transport and to produce starch
D) For respiration and to produce glucose
Answer: B) For respiration and to produce amino acids
Rationale: Plants use the glucose produced during photosynthesis for respiration to
release energy and as a building block to synthesise other biological molecules like
amino acids, which are needed for protein synthesis. They also convert glucose to
cellulose and starch for structural and storage purposes respectively.
2. Define the term biomass.
A) The total mass of living organisms in a given area
B) The total mass of carbon in a living organism
C) The mass of organic material in living organisms, excluding water
D) The chemical energy stored in plant tissue
Answer: C) The mass of organic material in living organisms, excluding water
,Rationale: Biomass is the total dry mass of living tissue in an organism or trophic
level at a given time. It is a measure of the organic matter present.
3. State why dry biomass is a more accurate measurement than wet biomass.
A) It is easier to measure dry mass than wet mass
B) Dry mass removes the variable water content, allowing for a more accurate
comparison
C) Wet mass cannot be measured accurately
D) Dry mass is always larger than wet mass
Answer: B) Dry mass removes the variable water content, allowing for a more
accurate comparison
Rationale: The water content of organisms can vary significantly and does not
represent organic matter. Measuring dry biomass removes this variable, providing
a more accurate measure of the amount of biological material.
4. Describe how an organism's dry biomass would be calculated.
A) By weighing the organism fresh and recording the mass
B) By drying the organism in an oven at 80-100°C until a constant mass is
achieved and then weighing it
C) By burning the organism and measuring the ash content
D) By weighing the organism after it has been frozen
Answer: B) By drying the organism in an oven at 80-100°C until a constant mass is
achieved and then weighing it
Rationale: Dry biomass is determined by heating a sample at a specific temperature
to evaporate all water content. The sample is weighed repeatedly until its mass
becomes constant, ensuring all water has been removed. The final mass is recorded
as the dry biomass.
5. Describe how a calorimeter could be used to estimate the stored chemical energy
inside a dried plant sample.
A) By measuring the volume of water displaced by the sample
B) By burning the sample and using the heat released to warm a known volume of
water
C) By dissolving the sample in acid and measuring the temperature change
D) By measuring the oxygen consumed during combustion
Answer: B) By burning the sample and using the heat released to warm a known
volume of water
Rationale: A calorimeter is used to measure the energy content of food or
biological material. The dried sample is completely combusted in a sealed chamber
,surrounded by a known volume of water. The rise in temperature of the water is
used to calculate the energy released.
6. Suggest two reasons why a simple calorimeter may not produce a completely
accurate estimate of the energy stored inside plant tissue.
A) Incomplete combustion and heat loss to the surroundings
B) The sample is too large and the water volume is too small
C) The calorimeter is not calibrated correctly and the thermometer is faulty
D) The plant tissue is not dry enough and the water is not stirred
Answer: A) Incomplete combustion and heat loss to the surroundings
Rationale: In a simple calorimeter, not all the sample may combust completely,
meaning some energy is not released. Additionally, heat energy can be lost to the
surrounding environment, leading to an underestimate of the actual energy content.
7. Define the term gross primary production.
A) The chemical energy stored in plant biomass after respiratory losses
B) The total chemical energy converted from light energy by photosynthesis
C) The total energy available to primary consumers
D) The energy lost as heat during respiration
Answer: B) The total chemical energy converted from light energy by
photosynthesis
Rationale: Gross primary production (GPP) is the total amount of chemical energy
that is produced by plants in a given area and time through photosynthesis, before
any losses from respiration are accounted for.
8. Name the process indicated in a diagram of a simple food chain by which solar
energy is converted into GPP.
A) Respiration
B) Photosynthesis
C) Decomposition
D) Combustion
Answer: B) Photosynthesis
Rationale: The only biological process that converts light energy from the sun into
chemical energy (GPP) is photosynthesis, which is carried out by primary
producers such as plants.
9. The process of converting solar energy into GPP is not 100% efficient. Suggest
one reason why this might be the case.
A) Not all wavelengths of light are absorbed by chlorophyll
B) The plant cannot photosynthesise at night
, C) The plant is eaten by herbivores
D) The plant loses heat through respiration
Answer: A) Not all wavelengths of light are absorbed by chlorophyll
Rationale: The efficiency of photosynthesis is limited by several factors. One key
reason is that chlorophyll and other photosynthetic pigments do not absorb all
wavelengths of light. Some wavelengths are reflected or transmitted, meaning the
energy is not captured.
10. Explain why energy stored in the plant is not converted into biomass in the
consumer.
A) The energy is lost as heat during digestion
B) The energy is used for the consumer's respiration
C) Energy is lost in faeces and urine, or as heat
D) The energy is stored as fat in the consumer
Answer: C) Energy is lost in faeces and urine, or as heat
Rationale: When a consumer eats a plant, not all the energy stored in the plant's
biomass is absorbed. Some is lost in the consumer's faeces (undigested material)
and urine. The absorbed energy is then used for respiration (lost as heat) or
converted to new consumer biomass.
11. Use information provided in a diagram to calculate the net primary productivity
(NPP) of producers.
A) NPP = GPP - R, where R represents respiratory losses
B) NPP = GPP + R
C) NPP = GPP / R
D) NPP = GPP x R
Answer: A) NPP = GPP - R, where R represents respiratory losses
Rationale: Net primary production is the amount of chemical energy stored in plant
biomass after the plant has used some energy for its own respiration. The formula
is NPP = GPP - R, where R is the respiratory loss.
12. State the equation for the net production of consumers.
A) N = I - (F + R)
B) N = I + F - R
C) N = I - F - R
D) N = I - R
Answer: A) N = I - (F + R)
Rationale: The net production (N) of a consumer is calculated by subtracting the
energy lost in faeces (F) and through respiration (R) from the energy ingested (I).
This is the energy that is converted into new consumer biomass.
AND CORRECT ANSWERS WITH RATIONALE LATEST 2026
ALREADY GRADED A+
This AQA A-Level Biology examination comprehensively assesses
understanding of biological principles across diverse topics. It covers
biological molecules, including carbohydrates, proteins, and nucleic acids,
alongside cellular processes such as photosynthesis, respiration, and protein
synthesis. The exam evaluates genetics, including inheritance patterns,
mutations, and gene expression. Organismal biology is tested through gas
exchange, transport systems (xylem, phloem, circulatory), and the immune
response. Ecological principles, energy transfer, nutrient cycles, and
succession are also assessed. Candidates must demonstrate knowledge of
practical techniques, data analysis, and apply biological concepts to
unfamiliar scenarios, requiring both recall and critical thinking skills.
1. Give two ways in which plants use the molecules produced during
photosynthesis.
A) For respiration and to produce cellulose
B) For respiration and to produce amino acids
C) For active transport and to produce starch
D) For respiration and to produce glucose
Answer: B) For respiration and to produce amino acids
Rationale: Plants use the glucose produced during photosynthesis for respiration to
release energy and as a building block to synthesise other biological molecules like
amino acids, which are needed for protein synthesis. They also convert glucose to
cellulose and starch for structural and storage purposes respectively.
2. Define the term biomass.
A) The total mass of living organisms in a given area
B) The total mass of carbon in a living organism
C) The mass of organic material in living organisms, excluding water
D) The chemical energy stored in plant tissue
Answer: C) The mass of organic material in living organisms, excluding water
,Rationale: Biomass is the total dry mass of living tissue in an organism or trophic
level at a given time. It is a measure of the organic matter present.
3. State why dry biomass is a more accurate measurement than wet biomass.
A) It is easier to measure dry mass than wet mass
B) Dry mass removes the variable water content, allowing for a more accurate
comparison
C) Wet mass cannot be measured accurately
D) Dry mass is always larger than wet mass
Answer: B) Dry mass removes the variable water content, allowing for a more
accurate comparison
Rationale: The water content of organisms can vary significantly and does not
represent organic matter. Measuring dry biomass removes this variable, providing
a more accurate measure of the amount of biological material.
4. Describe how an organism's dry biomass would be calculated.
A) By weighing the organism fresh and recording the mass
B) By drying the organism in an oven at 80-100°C until a constant mass is
achieved and then weighing it
C) By burning the organism and measuring the ash content
D) By weighing the organism after it has been frozen
Answer: B) By drying the organism in an oven at 80-100°C until a constant mass is
achieved and then weighing it
Rationale: Dry biomass is determined by heating a sample at a specific temperature
to evaporate all water content. The sample is weighed repeatedly until its mass
becomes constant, ensuring all water has been removed. The final mass is recorded
as the dry biomass.
5. Describe how a calorimeter could be used to estimate the stored chemical energy
inside a dried plant sample.
A) By measuring the volume of water displaced by the sample
B) By burning the sample and using the heat released to warm a known volume of
water
C) By dissolving the sample in acid and measuring the temperature change
D) By measuring the oxygen consumed during combustion
Answer: B) By burning the sample and using the heat released to warm a known
volume of water
Rationale: A calorimeter is used to measure the energy content of food or
biological material. The dried sample is completely combusted in a sealed chamber
,surrounded by a known volume of water. The rise in temperature of the water is
used to calculate the energy released.
6. Suggest two reasons why a simple calorimeter may not produce a completely
accurate estimate of the energy stored inside plant tissue.
A) Incomplete combustion and heat loss to the surroundings
B) The sample is too large and the water volume is too small
C) The calorimeter is not calibrated correctly and the thermometer is faulty
D) The plant tissue is not dry enough and the water is not stirred
Answer: A) Incomplete combustion and heat loss to the surroundings
Rationale: In a simple calorimeter, not all the sample may combust completely,
meaning some energy is not released. Additionally, heat energy can be lost to the
surrounding environment, leading to an underestimate of the actual energy content.
7. Define the term gross primary production.
A) The chemical energy stored in plant biomass after respiratory losses
B) The total chemical energy converted from light energy by photosynthesis
C) The total energy available to primary consumers
D) The energy lost as heat during respiration
Answer: B) The total chemical energy converted from light energy by
photosynthesis
Rationale: Gross primary production (GPP) is the total amount of chemical energy
that is produced by plants in a given area and time through photosynthesis, before
any losses from respiration are accounted for.
8. Name the process indicated in a diagram of a simple food chain by which solar
energy is converted into GPP.
A) Respiration
B) Photosynthesis
C) Decomposition
D) Combustion
Answer: B) Photosynthesis
Rationale: The only biological process that converts light energy from the sun into
chemical energy (GPP) is photosynthesis, which is carried out by primary
producers such as plants.
9. The process of converting solar energy into GPP is not 100% efficient. Suggest
one reason why this might be the case.
A) Not all wavelengths of light are absorbed by chlorophyll
B) The plant cannot photosynthesise at night
, C) The plant is eaten by herbivores
D) The plant loses heat through respiration
Answer: A) Not all wavelengths of light are absorbed by chlorophyll
Rationale: The efficiency of photosynthesis is limited by several factors. One key
reason is that chlorophyll and other photosynthetic pigments do not absorb all
wavelengths of light. Some wavelengths are reflected or transmitted, meaning the
energy is not captured.
10. Explain why energy stored in the plant is not converted into biomass in the
consumer.
A) The energy is lost as heat during digestion
B) The energy is used for the consumer's respiration
C) Energy is lost in faeces and urine, or as heat
D) The energy is stored as fat in the consumer
Answer: C) Energy is lost in faeces and urine, or as heat
Rationale: When a consumer eats a plant, not all the energy stored in the plant's
biomass is absorbed. Some is lost in the consumer's faeces (undigested material)
and urine. The absorbed energy is then used for respiration (lost as heat) or
converted to new consumer biomass.
11. Use information provided in a diagram to calculate the net primary productivity
(NPP) of producers.
A) NPP = GPP - R, where R represents respiratory losses
B) NPP = GPP + R
C) NPP = GPP / R
D) NPP = GPP x R
Answer: A) NPP = GPP - R, where R represents respiratory losses
Rationale: Net primary production is the amount of chemical energy stored in plant
biomass after the plant has used some energy for its own respiration. The formula
is NPP = GPP - R, where R is the respiratory loss.
12. State the equation for the net production of consumers.
A) N = I - (F + R)
B) N = I + F - R
C) N = I - F - R
D) N = I - R
Answer: A) N = I - (F + R)
Rationale: The net production (N) of a consumer is calculated by subtracting the
energy lost in faeces (F) and through respiration (R) from the energy ingested (I).
This is the energy that is converted into new consumer biomass.
