Respiration — Paper 2 · IGCSE Sciences - Co-ordinated (9-1) 0973

24 Which processes lead to the formation of a greenhouse gas? 1 reaction of sodium with water 2 respiration 3 combustion of fossil fuels A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: C

This question in 0973/21 May/June 2019

8 After sprinting 200 metres as fast as possible, an athlete could not continue and was breathing deeply. What had accumulated in her muscles? A alcohol B carbon dioxide C lactic acid D water

1 marks

Answer: C

This question in 0973/22 May/June 2019

8 What are the products of the anaerobic respiration of glucose in yeast? A alcohol and carbon dioxide B alcohol only C lactic acid and carbon dioxide D lactic acid only

1 marks

Answer: A

This question in 0973/21 Oct/Nov 2019

10 An experiment using germinating seeds is set up as shown, and left at room temperature for 12 hours. to pump solution P solution Q germinating damp peas cotton wool The pump is then switched on and air is drawn through the apparatus for 2 minutes. Which row identifies solutions P and Q and the results obtained? solution P solution P results solution Q solution Q results A ethanol remains colourless ethanol turns milky B ethanol turns milky limewater remains colourless C limewater remains colourless limewater turns milky D limewater turns milky ethanol remains colourless

1 marks

Answer: C

This question in 0973/21 May/June 2020

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

1 marks

Answer: A

This question in 0973/21 Oct/Nov 2020

1 What is respiration? A breakdown of food by enzymes in the alimentary canal B breathing to supply oxygen to cells C release of carbon dioxide from the lungs D release of energy for body activities

1 marks

Answer: D

This question in 0973/21 May/June 2021

1 What is respiration? A breakdown of food by enzymes in the alimentary canal B breathing to supply oxygen to cells C release of carbon dioxide from the lungs D release of energy for body activities

1 marks

Answer: D

This question in 0973/22 May/June 2021

13 The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration? CO2 B C A green D animals plants fossil fuels

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2021

8 Which diagram gives the possible products of aerobic respiration and anaerobic respiration? A B aerobic anaerobic aerobic anaerobic lactic H2O H2O acid lactic alcohol acid CO2 CO2 alcohol C D aerobic anaerobic aerobic anaerobic lactic lactic acid acid CO2 H2O H2O CO2 alcohol alcohol

1 marks

Answer: D

This question in 0973/21 Oct/Nov 2022

1 What is meant by respiration? A protein synthesis B sweating to lose heat C the function of lungs D the release of energy

1 marks

Answer: D

This question in 0973/21 May/June 2023

8 Which statement about anaerobic respiration is correct? A It does not cause an oxygen debt. B It occurs in the muscles during vigorous exercise. C It uses oxygen to release energy from nutrient molecules. D It releases more energy per glucose molecule compared to aerobic respiration.

1 marks

Answer: B

This question in 0973/21 May/June 2023

8 During cold weather, warm blooded animals, such as mammals and birds, require more food. Which statement explains the reason for this? energy required to rate of maintain constant respiration body temperature A high high B high low C low high D low low

1 marks

Answer: A

This question in 0973/22 May/June 2023

1 Which characteristic of a living organism releases energy for growth? A excretion B reproduction C respiration D sensitivity

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2023

8 Aerobic respiration releases energy from nutrient molecules. One molecule of glucose requires … 1 … molecules of oxygen. The reaction releases … 2 … molecules of carbon dioxide and … 3 … molecules of water. Which row completes gaps 1, 2 and 3? 1 2 3 A six two two B two six six C two two two D six six six

1 marks

Answer: D

This question in 0973/21 Oct/Nov 2023

8 A student places a mixture of yeast and glucose in a boiling tube, as shown in the diagram. They cover the mixture with a layer of oil. A delivery tube is used to bubble gas produced by the yeast through limewater. After 10 minutes, the limewater is milky. screw clip (closed when experiment is started) oil yeast and glucose limewater solution Why does the limewater go milky? A The yeast produces carbon dioxide by anaerobic respiration. B The yeast produces lactic acid by anaerobic respiration. C The yeast produces carbon dioxide by photosynthesis. D The yeast produces oxygen by aerobic respiration.

1 marks

Answer: A

This question in 0973/22 May/June 2024

8 Yogurt is a food made by adding bacteria to milk. The bacteria feed on sugars in the milk and produce lactic acid. The lactic acid denatures the milk protein. Which process produces the lactic acid? A aerobic respiration B anaerobic respiration C assimilation D decomposition

1 marks

Answer: B

This question in 0973/21 May/June 2025

9 Two flasks are set up as shown. A student breathes out through tube X of flask 1. Another student breathes in through tube Y of flask 2. flask 1 flask 2 X Y limewater limewater The students obtain different results. Which body process causes this difference? A absorption B assimilation C digestion D respiration

1 marks

Answer: D

This question in 0973/21 Oct/Nov 2025