Respiration — IGCSE Biology (0970) questions by topic
Respiration questions identify how an oxygen debt is removed after vigorous exercise, choose the correct word equation for aerobic respiration, explain gas production in a yeast, sugar and water mixture, and decide which listed processes, such as cell division or osmosis, actually require energy from respiration.
Choose, state, identify, complete and calculate carry 1 to 14 marks across 32 real questions from 2023 to 2025 papers. Because word equations and process lists reward exact recall over approximate recognition, submitting each answer for instant marking pinpoints whether a reactant, product or listed process has been mixed up with its counterpart in anaerobic respiration.
May–June 2025, Paper 11
What is a product of anaerobic respiration in yeast cells? A alcohol B lactic acid C oxygen D water
Answer this question and get it marked →May–June 2025, Paper 12
Which statement is a correct comparison of aerobic respiration and anaerobic respiration in yeast? A Only aerobic respiration produces carbon dioxide. B Only anaerobic respiration…
Answer this question and get it marked →May–June 2025, Paper 21
The processes listed occur in living organisms. 1 cell division 2 diffusion 3 muscle contraction 4 osmosis Which processes require energy from respiration? A 1, 2, 3 and 4 B 1 and…
Answer this question and get it marked →May–June 2025, Paper 22
After a race, athletes experience oxygen debt. The diagram shows how the oxygen debt is removed. The diagram is a cycle: 'lactic acid forms in the muscles' leads to 'lactic acid…
Answer this question and get it marked →May–June 2024, Paper 11
What is the word equation for aerobic respiration? A carbon dioxide + glucose → oxygen + water B carbon dioxide + water → oxygen + glucose C oxygen + glucose → carbon dioxide +…
Answer this question and get it marked →May–June 2024, Paper 12
Some yeast, sugar and water are mixed in a test-tube. The diagrams show the test-tube at the start and after one hour (bubbles of gas are produced). Which process causes this…
Answer this question and get it marked →Which statement describes anaerobic respiration? A Anaerobic respiration in humans produces lactic acid and carbon dioxide. B Anaerobic respiration in yeast produces water and…
Answer this question and get it marked →May–June 2024, Paper 21
Vigorous exercise can cause an oxygen debt. Which process removes the oxygen debt? A aerobic respiration of lactic acid in the liver B a decrease in breathing rate C a decrease in…
Answer this question and get it marked →May–June 2024, Paper 22
Two molecules of glucose are aerobically respired. How many molecules of water are produced? A 1 B 2 C 6 D 12
Answer this question and get it marked →May–June 2024, Paper 31
Fig. 1.1 is a photograph showing different stages of bread-making. Bread dough is made by mixing flour, water and yeast together. Bread dough A has just been mixed. Bread dough B…
Answer this question and get it marked →May–June 2024, Paper 42
Fungal cells and plant cells contain mitochondria. State the function of mitochondria.
Answer this question and get it marked →October–November 2024, Paper 12
Which row matches a gas in expired air with a substance that can be used to test for the presence of that gas? gas present in expired air test substance --- --- --- A carbon…
Answer this question and get it marked →Which graph shows how temperature affects the rate of anaerobic respiration in yeast? Graph A: flat horizontal line (no change with temperature) Graph B: rises to a peak around…
Answer this question and get it marked →October–November 2024, Paper 22
What causes air to enter the lungs? external intercostal muscles volume of thorax air pressure in thorax --- --- --- --- A contract decreases decreases B relax decreases increases…
Answer this question and get it marked →The symbol equation for aerobic respiration is shown. C₆HₓOᵧ + 6O₂ → 6CO₂ + zH₂O Which numbers represent the letters shown in the equation as x, y and z? x y z --- --- --- --- A 2…
Answer this question and get it marked →A student investigates the rate of anaerobic respiration in yeast. The total volume of carbon dioxide produced is measured every 10 minutes for 40 minutes. The table shows the…
Answer this question and get it marked →May–June 2023, Paper 11
The diagram shows yeast cells in a sugar solution producing gas bubbles that pass into limewater. Which statement explains what happens to the limewater? A The limewater changes…
Answer this question and get it marked →What is the word equation for aerobic respiration? A carbon dioxide + water → glucose + oxygen B glucose + oxygen → carbon dioxide + water C glycogen + oxygen → carbon dioxide +…
Answer this question and get it marked →May–June 2023, Paper 12
Which chemical can be used to show the presence of carbon dioxide gas? A Benedict's solution B biuret solution C ethanol D limewater
Answer this question and get it marked →Which molecule is produced by anaerobic respiration in yeast? A carbon dioxide B lactic acid C oxygen D water
Answer this question and get it marked →May–June 2023, Paper 21
In the chemical equation for anaerobic respiration in yeast, the numbers have been replaced by the letters W, X, Y and Z: CWHXOW → YCYHZOH + YCOY Which number is Z? A 2 B 5 C 6 D…
Answer this question and get it marked →A student measured their oxygen consumption before, during and after exercise. The graph shows oxygen consumption (dm3 per minute) against time (minutes) across at rest, during…
Answer this question and get it marked →May–June 2023, Paper 22
Which row shows aerobic respiration? Columns: substrates; products. A 6CO2 + 6H2O; C6H12O6 + 6O2 B C6H12O6 + 6CO2; 6H2O + 6O2 C 6CO2 + 6O2; C6H12O6 + 6H2O D C6H12O6 + 6O2; 6CO2 +…
Answer this question and get it marked →In which organ is lactic acid respired aerobically to remove an oxygen debt? A brain B heart C liver D lungs
Answer this question and get it marked →May–June 2023, Paper 32
Complete the sentences about anaerobic respiration in humans, using words or phrases from the list (alcohol, breaks down, builds up, carbon dioxide, element, lactic acid, less,…
Answer this question and get it marked →May–June 2023, Paper 41
A scientist monitored the changes in the pH in muscles before, during and after two minutes of vigorous exercise. The changes in pH are caused by the production of lactic acid.…
Answer this question and get it marked →October–November 2023, Paper 12
Yeast cells can convert glucose into alcohol and carbon dioxide. Which statement about this process is correct? A The alcohol produced can be used to make bread rise. B The carbon…
Answer this question and get it marked →In an experiment to investigate anaerobic respiration, two bottles with balloons are set up in a warm room: P contains sugar, yeast and water; Q contains yeast and water. Diagrams…
Answer this question and get it marked →A student investigated gas exchange using apparatus with a mouthpiece connected to two tubes (tube X and tube Y) of limewater. What would be the appearance of the limewater in…
Answer this question and get it marked →October–November 2023, Paper 22
The graph shows the results of an experiment to investigate the rate of respiration in an organism in different environmental temperatures (10–40 °C). What explains the increase…
Answer this question and get it marked →Yeast cells can convert glucose into alcohol and carbon dioxide. Which statement about this process is correct? A The alcohol produced can be used to make bread rise. B The carbon…
Answer this question and get it marked →What is the correct balanced equation for one type of respiration? A C2H5OH → 2C6H12O6 + 2CO2 B 2C2H5OH → C6H12O6 + 2H2O C C6H12O6 → 2C2H5OH + 2CO2 D C6H12O6 → 2C2H5OH + 2H2O
Answer this question and get it marked →Other IGCSE Biology topics
- Human nutrition (75)
- Organisms and their environment (64)
- Coordination and response (62)
- Reproduction (53)
- Organisation of the organism (cells) (50)
- Plant nutrition (42)
- Characteristics and classification of living organisms (40)
- Variation and selection (40)
- Transport in animals (39)
- Inheritance (39)
- Movement into and out of cells (38)
- Transport in plants (38)