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

21 Which row describes anaerobic respiration? energy oxygen waste products released required A a little no lactic acid B a little yes carbon dioxide and water C a lot no lactic acid D a lot yes carbon dioxide and water

1 marks

Answer: A

This question in 0970/11 May/June 2018

37 The production of ethanol for biofuels involves two stages. Firstly, starch is converted to glucose by … 1 … . Secondly, glucose is converted to ethanol by … 2 … during … 3 … . Which row correctly completes gaps 1, 2 and 3? 1 2 3 A enzymes bacteria aerobic respiration B enzymes yeast anaerobic respiration C pectinase bacteria aerobic respiration D pectinase yeast anaerobic respiration

1 marks

Answer: B

This question in 0970/12 Oct/Nov 2018

24 Yeast is placed inside a container full of a glucose solution with no air. Which word equation summarises the process that takes place inside the container? A glucose → ethanol + carbon dioxide B glucose → lactic acid C glucose + oxygen → carbon dioxide + water D glucose + oxygen → ethanol

1 marks

Answer: A

This question in 0970/11 May/June 2019

21 Which process releases the most energy from one molecule of glucose? A aerobic respiration B anaerobic respiration in muscle C anaerobic respiration in yeast D photosynthesis

1 marks

Answer: A

This question in 0970/12 Oct/Nov 2019

19 The diagram shows an experiment to investigate the respiration of yeast. Oil prevents oxygen entering the glucose and yeast suspension. delivery tube thin layer of oil bubble of gas glucose and yeast limewater suspension If no oxygen is present in the glucose and yeast suspension, what will occur? A Ethanol will be produced and the limewater will stay clear. B Ethanol will be produced and the limewater will go cloudy. C Lactic acid will be produced and the limewater will stay clear. D Lactic acid will be produced and the limewater will go cloudy.

1 marks

Answer: B

This question in 0970/11 May/June 2020

37 What is the role of anaerobic respiration in bread-making? A to produce alcohol to flavour the bread B to produce gas to make the bread rise C to release enough energy to bake the bread D to release enough lactic acid to kill the yeast

1 marks

Answer: B

This question in 0970/11 May/June 2020

37 What is the role of anaerobic respiration in bread-making? A to produce alcohol to flavour the bread B to produce gas to make the bread rise C to release enough energy to bake the bread D to release enough lactic acid to kill the yeast

1 marks

Answer: B

This question in 0970/12 May/June 2020

23 What is produced during anaerobic respiration in muscles? A carbon dioxide B ethanol C lactic acid D water

1 marks

Answer: C

This question in 0970/12 Oct/Nov 2020

24 What is produced by anaerobic respiration in humans? alcohol carbon dioxide lactic acid A x Jv Jv key B Jv Jv x /=yes Cc x x v X=no D v x x

1 marks

Answer: C

This question in 0970/11 May/June 2021

24 Yeast is an organism used in the production of biofuels. Which statement describes why yeast is used for biofuel production? A Yeast respires aerobically to produce carbon dioxide. B Yeast respires aerobically to produce carbon dioxide and ethanol. C Yeast respires anaerobically to produce carbon dioxide. D Yeast respires anaerobically to produce carbon dioxide and ethanol.

1 marks

Answer: D

This question in 0970/12 Oct/Nov 2021

39 What is the useful product of anaerobic respiration in the manufacture of bread? A carbon dioxide B ethanol C lactic acid D oxygen

1 marks

Answer: A

This question in 0970/12 Oct/Nov 2021

23 What is the word equation for anaerobic respiration in yeast? A glucose  alcohol B glucose  alcohol + carbon dioxide C glucose  lactic acid D glucose  lactic acid + carbon dioxide

1 marks

Answer: B

This question in 0970/12 May/June 2022

24 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 0970/12 Oct/Nov 2022

23 The diagram shows the activity of some yeast cells in a sugar solution. sugar solution gas bubble yeast cells limewater Which statement explains what happens to the limewater? A The limewater changes from colourless to cloudy due to the presence of carbon dioxide. B The limewater changes from colourless to cloudy due to the presence of oxygen. C The limewater changes from cloudy to colourless due to the presence of carbon dioxide. D The limewater changes from cloudy to colourless due to the presence of oxygen.

1 marks

Answer: A

This question in 0970/11 May/June 2023

24 Which molecule is produced by anaerobic respiration in yeast? A carbon dioxide B lactic acid C oxygen D water

1 marks

Answer: A

This question in 0970/12 May/June 2023

23 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 dioxide produced can be burnt as a biofuel. C The yeast cells are using oxygen for this process. D The yeast cells are carrying out anaerobic respiration.

1 marks

Answer: D

This question in 0970/12 Oct/Nov 2023

24 In an experiment to investigate anaerobic respiration, two bottles are set up in a warm room, as shown. balloon balloon sugar, yeast yeast and water and water P Q What would happen to each balloon after one day? A B P Q P Q C D P Q P Q

1 marks

Answer: A

This question in 0970/12 Oct/Nov 2023

34 What is a use of yeast in biotechnology? A aerobic respiration to make biofuels B anaerobic respiration to make bread C aerobic respiration to make alcohol D anaerobic respiration to make human proteins

1 marks

Answer: B

This question in 0970/11 May/June 2024

23 Which statement describes anaerobic respiration? A Anaerobic respiration in humans produces lactic acid and carbon dioxide. B Anaerobic respiration in yeast produces water and carbon dioxide. C Anaerobic respiration releases energy from glucose without using oxygen. D Anaerobic respiration releases more energy per glucose molecule than aerobic respiration.

1 marks

Answer: C

This question in 0970/12 May/June 2024

39 What is a use of ethanol? A biofuel production B biological washing powder C bread-making D fruit juice production

1 marks

Answer: A

This question in 0970/12 May/June 2024

26 Which graph shows how temperature affects the rate of anaerobic respiration in yeast? A B anaerobic anaerobic respiration respiration rate rate 0 50 0 50 temperature / °C temperature / °C C D anaerobic anaerobic respiration respiration rate rate 0 50 0 50 temperature / °C temperature / °C

1 marks

Answer: B

This question in 0970/12 Oct/Nov 2024

22 What is a product of anaerobic respiration in yeast cells? A alcohol B lactic acid C oxygen D water

1 marks

Answer: A

This question in 0970/11 May/June 2025

21 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 produces alcohol. C They both produce water. D They both use the reactants glucose and oxygen.

1 marks

Answer: B

This question in 0970/12 May/June 2025

40 The flow chart shows some of the processes involved in making biofuel. grind up plant add organism L filter to biomass for anaerobic extract M biofuel remove waste to extract K respiration of K What are represented by K, L and M in the diagram? K L M A ethanol bacteria glucose B glucose yeast ethanol C glucose bacteria water D lactic acid yeast glucose

1 marks

Answer: B

This question in 0970/12 May/June 2025

17 Which substance is produced in human muscles during anaerobic respiration? A alcohol B carbon dioxide C lactic acid D urea

1 marks

Answer: C

This question in 0970/12 Oct/Nov 2025