GCSE Biology Respiration questions by topic

Complete the equations and definitions.

1. (a)Aerobic respiration: glucose + __________ → carbon dioxide + water.[1]
2. (b)Anaerobic respiration in muscles: glucose → __________.[1]
3. (c)Fermentation in yeast: glucose → ethanol + __________.[1]
4. (d)Respiration transfers energy and is described as an __________ reaction.[1]

A cyclist’s heart rate and breathing rate are measured before and during hard effort.

1. (a)Calculate the heart rate increase as a percentage.[2]
2. (b)Explain why breathing rate rises during effort.[2]

Sort each reaction into metabolism.

1. (a)Glucose → glycogen (name the organism group).[1]
2. (b)Excess protein → urea.[1]
3. (c)Glucose + nitrate ions → amino acids.[1]
4. (d)Glycerol + fatty acids → lipids.[1]

A baker leaves dough in a warm place for an hour and it doubles in size.

1. (a)Name the process happening in the yeast.[1]
2. (b)Name the gas that raises the dough.[1]
3. (c)State what happens to the ethanol produced.[1]

Match each body response during exercise to the reason it happens.

1. (a)Heart rate rises.[1]
2. (b)Breathing rate rises.[1]
3. (c)Glycogen stores are broken down.[1]
4. (d)Skin flushes and sweating starts.[1]

A brewer mixes yeast with sugar solution in a sealed flask with an airlock and keeps it warm.

1. (a)Name the process happening in the yeast.[1]
2. (b)Name the two products of this process.[1]
3. (c)Explain why the flask is kept warm.[1]
4. (d)State what the airlock lets out and keeps in.[1]

Explain the body’s responses to vigorous exercise.

1. (a)Explain the three coordinated increases.[3]
2. (b)Explain the role of glycogen.[2]
3. (c)State what happens if oxygen supply still falls short.[1]

Compare aerobic and anaerobic respiration in muscles.

1. (a)Give two differences in the reactions.[2]
2. (b)Explain why anaerobic respiration fatigues the muscles.[2]
3. (c)Explain what happens to the lactic acid after exercise.[2]

A student recovers from a 400 m sprint and records her pulse every minute.

1. (a)Calculate the fall in pulse during the first two minutes.[2]
2. (b)Explain why the pulse stays high after the sprint.[2]
3. (c)State one measurement, besides pulse, that would also fall during recovery.[1]

Explain why respiration is described as exothermic and why that matters to the whole body.

1. (a)Explain the exothermic description.[2]
2. (b)Explain two consequences for the body.[3]

A student measured a runner’s pulse at rest, during hard exercise and during recovery.

1. (a)Calculate the percentage increase in pulse from rest to hard exercise.[2]
2. (b)Describe what happens to the pulse after the runner stops.[1]
3. (c)Explain why breathing and pulse stay above resting levels for several minutes after exercise ends.[2]

Compare aerobic and anaerobic respiration in human muscle.

1. (a)Give the products of each type of respiration.[2]
2. (b)State which type transfers more energy per glucose molecule.[1]
3. (c)Explain why sprinters rely on the anaerobic pathway.[1]
4. (d)Explain why marathon runners rely on the aerobic pathway.[2]

(Higher) After a race, an athlete breathes deeply for eight minutes although she is standing still.

1. (a)Explain fully why the breathing rate remains high.[4]
2. (b)State two other changes that continue during recovery.[2]

A brewer and a baker both rely on yeast.

1. (a)Explain the role of yeast in each process.[4]
2. (b)Explain one condition the baker must control and why.[2]

Explain how the energy transferred by respiration is used in the cells of your body.

1. (a)Write a full answer covering several metabolic uses.[6]

Two identical runners complete the same sprint. Runner A trains regularly; runner B is untrained. Runner B’s recovery breathing lasts noticeably longer.

1. (a)Suggest an explanation in terms of respiration.[3]
2. (b)State the measurement that would show the difference most directly, and how.[2]

Explain why anaerobic respiration can support a sprint but not a marathon.

1. (a)Write a full explanation covering energy yield, fuel and waste.[6]

A baker sets up two identical dough balls — one with yeast, one without — and leaves both covered in a warm place for an hour.

1. (a)State which dough ball rises and name the gas that fills it.[2]
2. (b)Explain where the gas comes from.[2]
3. (c)A third dough ball with yeast is left in a fridge at 4 °C and barely rises. Explain why.[2]