GCSE Biology (AQA) chapter 4: Bioenergetics MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
26 exam-style questions on Bioenergetics, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. During exercise a person’s heart rate rose from 70 to 154 beats per minute. What was the percentage increase in heart rate?
A
54%
B
84%
C
120%
D
220%
Show answer
Answer: C. The increase was 154 − 70 = 84 beats per minute. 84 ÷ 70 × 100 = 120%. A higher heart rate delivers oxygenated blood to the muscles faster. 84 is the increase itself and 220% is 154 as a percentage of 70.
2. Which is the balanced symbol equation for photosynthesis?
A
C6H12O6 + 6O2 → 6CO2 + 6H2O
B
6CO2 + 6H2O → C6H12O6 + 6O2
C
CO2 + H2O → C6H12O6 + O2
D
6CO2 + 6O2 → C6H12O6 + 6H2O
Show answer
Answer: B. Carbon dioxide and water make glucose and oxygen, with light. The reverse equation is aerobic respiration, and the version without the 6s is not balanced.
3. Why does anaerobic respiration transfer much less energy than aerobic respiration?
A
the reaction takes place much more slowly in the cytoplasm
B
the cell uses much more glucose per second
C
the glucose is only broken down in the chloroplasts
D
the glucose is only partly broken down, so it is not fully oxidised
Show answer
Answer: D. Without oxygen, glucose is only partly broken down, so much of its energy remains in the lactic acid or ethanol.
4. Why do plants store glucose as starch rather than as glucose?
A
starch dissolves more easily, so it moves faster
B
starch is needed to build strong cell walls
C
starch can be used directly for respiration in the mitochondria
D
starch is insoluble, so it does not change osmosis
Show answer
Answer: D. Starch is insoluble, so it can be stored without drawing water into cells by osmosis. Cellulose, not starch, strengthens cell walls.
5. Which statement about respiration is correct?
A
it happens only in animal cells, not in plants
B
it is endothermic and happens in the chloroplasts
C
it is exothermic and happens in all living cells
D
it happens only when an organism is exercising
Show answer
Answer: C. Respiration transfers energy to the cell and the surroundings (exothermic) in all living cells, including plants, all the time.
6. At rest a person takes 15 breaths per minute of 500 cm3 each. During exercise they take 30 breaths per minute of 1500 cm3 each. By what factor does the volume of air breathed per minute increase?
A
2
B
3
C
6
D
9
Show answer
Answer: C. At rest: 15 × 500 = 7500 cm3 per minute. Exercise: 30 × 1500 = 45 000 cm3 per minute. 45 000 ÷ 7500 = 6.
7. What is produced by anaerobic respiration in human muscle cells?
A
ethanol and carbon dioxide
B
lactic acid
C
carbon dioxide and water
D
lactic acid and carbon dioxide
Show answer
Answer: B. In muscles, glucose is converted to lactic acid only. Ethanol and carbon dioxide are made by yeast and plant cells.
8. Which is the word equation for aerobic respiration?
A
glucose → lactic acid
B
carbon dioxide + water → glucose + oxygen
C
glucose → ethanol + carbon dioxide
D
glucose + oxygen → carbon dioxide + water
Show answer
Answer: D. Aerobic respiration uses oxygen to break down glucose completely to carbon dioxide and water. Carbon dioxide + water → glucose + oxygen is photosynthesis.
9. A lamp is moved from 30 cm to 10 cm from a plant. By what factor does the light intensity at the plant increase?
A
3
B
6
C
9
D
27
Show answer
Answer: C. The distance is divided by 3, so the intensity is multiplied by 32 = 9. Choosing 3 ignores the square.
10. What do plants make from glucose to strengthen their cell walls?
A
cellulose fibres
B
glycogen fibres in the wall
C
starch grains laid down in the wall
D
lipid membranes wrapped round the wall
Show answer
Answer: A. Glucose is used to make cellulose for cell walls. Starch is a store, and glycogen is the storage carbohydrate in animals.
26, each with the answer and a short explanation, across 2 topics: 4.4.1 Photosynthesis, 4.4.2 Respiration. Every chapter test draws ten of them, so you can take it many times.
Is the GCSE Biology (AQA) chapter 4 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
