Aerobic respiration — Paper 2 · IGCSE Biology (9-1) 0970

5 In which part of the cell does aerobic respiration occur? A cytoplasm B mitochondrion C ribosome D vesicle

1 marks

Answer: B

This question in 0970/21 May/June 2018

21 Yeast is able to respire both aerobically and anaerobically. Which statement describes the waste products of yeast respiration? A Aerobic respiration produces alcohol as one of its waste products. B Aerobic respiration produces three times as much carbon dioxide as anaerobic respiration from one molecule of glucose. C Anaerobic respiration and aerobic respiration both produce the same amount of carbon dioxide from one molecule of glucose. D Anaerobic respiration produces three times as much carbon dioxide as aerobic respiration from one molecule of glucose.

1 marks

Answer: B

This question in 0970/21 May/June 2018

11 The diagram shows an experiment to investigate the balance between respiration and photosynthesis. In which tube are photosynthesis and respiration taking place at the same time? A B C D black water polythene to keep snail out light light light light pond weed

1 marks

Answer: C

This question in 0970/21 May/June 2019

23 Which statement about both aerobic and anaerobic respiration is correct? A They break down C6H12O6. B They produce an oxygen debt. C They use CO2. D They use O2.

1 marks

Answer: A

This question in 0970/21 May/June 2019

3 Heart muscle cells have a high rate of metabolism. Which structure do they require to be present in high numbers? A chloroplasts B mitochondria C cell walls D vacuoles

1 marks

Answer: B

This question in 0970/22 May/June 2019

11 The diagram shows an experiment to investigate the balance between respiration and photosynthesis. In which tube are photosynthesis and respiration taking place at the same time? A B C D black water polythene to keep snail out light light light light pond weed

1 marks

Answer: C

This question in 0970/22 May/June 2019

23 Oxygen is required for aerobic respiration. How many molecules of oxygen are required for the aerobic respiration of three molecules of glucose? A 3 B 6 C 12 D 18

1 marks

Answer: D

This question in 0970/22 May/June 2019

36 The diagram shows how sewage is treated. air out second settling aeration screen settling water to river tank tank tank sludge air in sludge sludge sludge disposal digester Why is air bubbled through the aeration tank? A to encourage microorganisms to reproduce quickly B to float the sludge C to settle the sludge D to stop microorganisms from reproducing too quickly

1 marks

Answer: A

This question in 0970/22 May/June 2019

20 What is the effect on germinating seeds of increasing the temperature from 10 °C to 20 °C? A a decrease in the production of oxygen B a decrease in the respiration rate C an increase in the respiration rate D an increase in the transpiration rate

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2019

22 Which row correctly completes the balanced equation for aerobic respiration? X + 6O2 → 6CO2 + Y X Y A 6C6H12O6 H2O B C6H12O6 6H2O C 6H2O C6H12O6 D C6H10O6 6H2O

1 marks

Answer: B

This question in 0970/21 May/June 2020

21 The substances listed are associated with aerobic respiration. 1 carbon dioxide 2 glucose 3 oxygen 4 water Which substances are the products of aerobic respiration? A 1 and 3 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: B

This question in 0970/22 May/June 2020

24 Which equation is aerobic respiration? A 6CO2 + 6H2O  6C6H12O6 + 6O2 B 6O2 + 6CO2  6H2O + C6H12O6 C C6H12O6 + 6O2  6CO2 + 6H2O D C6H12O6  2C2H5OH + 2CO2

1 marks

Answer: C

This question in 0970/21 May/June 2021

22 The diagram shows the apparatus used to measure the rate of respiration in germinating seeds. As the seeds respire, the bubble of coloured water moves along the glass tube. glass tube germinating soda lime bubble of seeds (to absorb coloured water carbon dioxide) The temperature is increased from 20 C to 40 C. What happens to the movement of the bubble as the temperature increases? A The bubble moves more quickly towards the seeds at 40 C than at 20 C. B The bubble moves more quickly away from the seeds at 40 C than at 20 C. C The bubble moves more quickly towards the seeds at 20 C than at 40 C. D The bubble moves more quickly away from the seeds at 20 C than at 40 C.

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2021

21 Germinating seeds respire aerobically to release energy that can be used for growth. The balanced equation for aerobic respiration in seeds can be represented as shown. Q + R  S + T Which row gives the balanced equation for aerobic respiration in seeds? Q R S T A 6CO2 6H2O C6H12O6 6O2 B C6H12O6 6O2 6CO2 6H2O C 6CO2 6O2 C6H12O6 6H2O D C6H12O6 6H2O 6CO2 6O2

1 marks

Answer: B

This question in 0970/22 May/June 2022

22 During vigorous exercise, lactic acid builds up in muscles leading to an oxygen debt. Which statement describes a stage in the removal of the oxygen debt during recovery? A Anaerobic respiration breaks down lactic acid in the muscles. B Aerobic respiration breaks down lactic acid in the muscles. C Anaerobic respiration breaks down lactic acid in the liver. D Aerobic respiration breaks down lactic acid in the liver.

1 marks

Answer: D

This question in 0970/22 May/June 2022

5 Some examples of substances moving across membranes are listed. 1 glucose molecules into the epithelium that lines the small intestine 2 nitrate ions from a dilute solution in soil into a more concentrated solution in root hair cells 3 water molecules from mesophyll cells into the air spaces of a leaf For which examples must oxygen be present? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2022

21 Which process could continue without energy from respiration? A active transport B growth C osmosis D protein synthesis

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2022

22 Which row shows the products of anaerobic respiration in humans and yeast? products in humans products in yeast A lactic acid only alcohol only B lactic acid only alcohol and carbon dioxide C lactic acid and carbon dioxide alcohol only D lactic acid and carbon dioxide alcohol and carbon dioxide

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2022

22 A student measured their oxygen consumption before, during and after exercise. The results are shown in the graph. at rest during exercise after exercise 3.0 2.5 2.0 oxygen consumption 1.5 / dm3 per minute 1.0 0.5 0.0 0 5 10 15 20 25 time / minutes At which time is the oxygen debt being removed? A 5–10 minutes B 5–15 minutes C 15–20 minutes D 20–25 minutes

1 marks

Answer: C

This question in 0970/21 May/June 2023

6 Which row shows the changes that occur during the germination of a seed? respiration amount of how ions are rate energy required absorbed A decreased decreased active transport B decreased increased diffusion C increased decreased diffusion D increased increased active transport

1 marks

Answer: D

This question in 0970/22 May/June 2023

21 Which row shows aerobic respiration? substrates products A 6CO2 + 6H2O C6H12O6 + 6O2 B C6H12O6 + 6CO2 6H2O + 6O2 C 6CO2 + 6O2 C6H12O6 + 6H2O D C6H12O6 + 6O2 6CO2 + 6H2O

1 marks

Answer: D

This question in 0970/22 May/June 2023

10 The graph shows the results of an experiment to investigate the rate of respiration in an organism in different environmental temperatures. rate of respiration 0 10 15 20 25 30 35 40 temperature / °C What explains the increase in the rate of respiration between 10 °C and 30 °C? A The enzymes are denaturing. B There are more frequent effective collisions between enzyme and substrate molecules. C There are fewer enzyme-substrate complexes formed. D There is less kinetic energy.

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2023

12 The diagram shows a cell with groups of bacteria around its edge. cell cytoplasm spiral-shaped chloroplast bacteria The bacteria have moved to areas of high oxygen concentration. Which process in the cell causes the bacteria to form these groups? A digestion B photosynthesis C reproduction D respiration

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2023

6 Which process requires energy from respiration? A active transport B diffusion C osmosis D transpiration

1 marks

Answer: A

This question in 0970/21 May/June 2024

24 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 heart rate D an increase in blood supply to the skin

1 marks

Answer: A

This question in 0970/21 May/June 2024

4 What is the function of mitochondria in cells? A to absorb light energy B to produce glucose C to release energy D to transport oxygen

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2024

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? x y z A 2 12 6 B 6 2 12 C 6 12 2 D 12 6 2

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2024

22 After a race, athletes experience oxygen debt. The diagram shows how the oxygen debt is removed. lactic acid forms in the muscles lactic acid moves in X the blood to the liver faster breathing supplies extra oxygen What happens at X? A aerobic respiration of glucose B aerobic respiration of lactic acid C anaerobic respiration of glucose D anaerobic respiration of lactic acid

1 marks

Answer: B

This question in 0970/22 May/June 2025