Respiration — IGCSE Biology (0610) questions by topic
Respiration questions choose the correct word equation for aerobic respiration, decide which listed processes such as cell division or muscle contraction actually need energy from respiration, pick the row showing aerobic respiration's substrates and products, and select the balanced equation for fermentation in yeast.
Identify, state, complete, calculate and compare span 1 to 14 marks across 48 real questions from 2023 to 2025 papers. Because aerobic and anaerobic equations share several of the same terms in different positions, submitting each chosen answer for instant marking flags immediately whether a reactant and product have been swapped between the two processes.
May–June 2025, Paper 11
The diagram shows apparatus that was used to investigate germination in seeds. (The diagram shows a horizontal test-tube containing germinating seeds at the closed end, then a…
Answer this question and get it marked →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 13
Which structure is the site of aerobic respiration in plant cells? A chloroplast B mitochondrion C nucleus D ribosome
Answer this question and get it marked →Which substance is a product of anaerobic respiration in human muscles? A alcohol B carbon dioxide C glucose D lactic acid
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
What is the chemical formula of glucose? A C6H6O6 B C6HO6 C C6H12O6 D C12H12O6
Answer this question and get it marked →After a race, athletes experience oxygen debt. The diagram shows how the oxygen debt is removed as a cycle: lactic acid forms in the muscles - lactic acid moves in the blood to…
Answer this question and get it marked →May–June 2025, Paper 23
Which process in plants uses energy from respiration? A cell division B osmosis C photosynthesis D transpiration
Answer this question and get it marked →Which sequence of statements explains the build-up and removal of an oxygen debt? 1 Anaerobic respiration occurs in muscles during vigorous exercise. 2 Faster and deeper breathing…
Answer this question and get it marked →October–November 2024, Paper 11
Which substances are used and produced in aerobic respiration in a plant cell? (columns: substances used; substances produced) A carbon dioxide and glucose; oxygen and water B…
Answer this question and get it marked →October–November 2024, Paper 12
Which graph shows how temperature affects the rate of anaerobic respiration in yeast? (anaerobic respiration rate vs temperature 0-50 C) A graph A B graph B C graph C D graph D
Answer this question and get it marked →October–November 2024, Paper 13
What is the equation for aerobic respiration? A glucose + carbon dioxide - oxygen + water B glucose + oxygen - carbon dioxide + water C water + carbon dioxide - glucose + oxygen D…
Answer this question and get it marked →October–November 2024, Paper 21
How many molecules of carbon dioxide, glucose, oxygen and water are there in the balanced chemical equation for aerobic respiration? (columns: carbon dioxide; glucose; oxygen;…
Answer this question and get it marked →October–November 2024, Paper 22
The symbol equation for aerobic respiration is shown: C6HxOy + 6O2 - 6COz + 6H2O. Which numbers represent the letters shown in the equation as x, y and z? (columns: 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. Results (time / min :…
Answer this question and get it marked →October–November 2024, Paper 23
Which molecule is a product of anaerobic respiration in yeast? A C2H5OH B C6H12O6 C H2O D O2
Answer this question and get it marked →October–November 2024, Paper 31
Yeast can respire anaerobically. The box on the left ('Anaerobic respiration in yeast') shows the beginning of a sentence. The boxes on the right show some sentence endings:…
Answer this question and get it marked →October–November 2024, Paper 33
A student investigated the concentration of lactic acid in the blood of an athlete during a 400 m race. Fig. 5.1 shows the results of the investigation. Using the information in…
Answer this question and get it marked →October–November 2024, Paper 43
Human muscle cells use anaerobic respiration during vigorous exercise. State the word equation for anaerobic respiration in humans.
Answer this question and get it marked →May–June 2023, Paper 11
The diagram shows the activity of some yeast cells in a sugar solution; a gas bubble passes into limewater. Which statement explains what happens to the limewater? A The limewater…
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 13
Which row about aerobic respiration is correct? Columns: substrates; products. A glucose + carbon dioxide; oxygen + water B glucose + carbon dioxide; oxygen only C glucose +…
Answer this question and get it marked →What is a product of anaerobic respiration in yeast? A alcohol B glucose 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: C(W)H(X)O(W) → Y·C(Y)H(Z)OH + Y·CO(Y). Which number is Z?…
Answer this question and get it marked →A student measured their oxygen consumption before, during and after exercise. The results are shown in the graph (oxygen consumption / dm³ per minute against time / minutes, with…
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 23
After running a fast race, some students have pains in their leg muscles due to a build up of lactic acid. A student wrote this explanation. 1 During the race, the cells did not…
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 (each may be used once, more than once or not at all): alcohol, breaks down,…
Answer this question and get it marked →May–June 2023, Paper 33
Fig. 5.1 is a diagram of a cell carrying out one type of respiration. The arrows show the direction of movement of the substances involved (oxygen and substance A enter; carbon…
Answer this question and get it marked →May–June 2023, Paper 41
A scientist monitored the changes in pH in muscles before, during and after two minutes of vigorous exercise; the changes are caused by the production of lactic acid (Fig. 6.1: pH…
Answer this question and get it marked →October–November 2023, Paper 11
Three statements about anaerobic respiration are listed. 1 In humans, the product is lactic acid. 2 In yeast, the product is lactic acid. 3 It releases more energy per glucose…
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 are set up in a warm room: bottle P contains sugar, yeast and water; bottle Q contains yeast and water (no…
Answer this question and get it marked →A student investigated gas exchange using apparatus with a mouthpiece connected to two tubes (X and Y) of limewater, so that one tube samples inhaled air and the other exhaled…
Answer this question and get it marked →October–November 2023, Paper 13
Which statement about anaerobic respiration is correct? A Anaerobic respiration requires oxygen and releases less energy per glucose molecule than aerobic respiration. B Anaerobic…
Answer this question and get it marked →Which graph shows the effect of temperature on the rate of respiration in yeast? Each option A–D plots rate of respiration against temperature. The correct graph (A) rises to a…
Answer this question and get it marked →October–November 2023, Paper 21
Three statements about anaerobic respiration are listed. 1 In humans, the product is lactic acid. 2 In yeast, the product is lactic acid. 3 It releases more energy per glucose…
Answer this question and get it marked →What is the balanced chemical equation for a type of respiration that occurs in yeast? A C₆H₁₂O₆ + O₂ → CO₂ + 6H₂O B 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ C C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ D…
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 (rate of respiration against temperature…
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 →October–November 2023, Paper 23
Which statement about anaerobic respiration is correct? A Anaerobic respiration requires oxygen and releases less energy per glucose molecule than aerobic respiration. B Anaerobic…
Answer this question and get it marked →During exercise an oxygen debt may occur in muscles. What is the cause of this oxygen debt? A Aerobic respiration causes a decrease in lactic acid. B Aerobic respiration causes an…
Answer this question and get it marked →October–November 2023, Paper 41
Fig. 6.1 is a diagram showing how glucose is used by different organisms. Glucose can be converted to cellulose, sucrose and starch; process 3 produces carbon dioxide and water;…
Answer this question and get it marked →Other IGCSE Biology topics
- Organisms and their environment (126)
- Human nutrition (95)
- Characteristics and classification of living organisms (84)
- Coordination and response (83)
- Reproduction (82)
- Inheritance (74)
- Organisation of the organism (cells) (64)
- Plant nutrition (62)
- Transport in animals (62)
- Transport in plants (59)
- Movement into and out of cells (57)
- Variation and selection (50)