Gas exchange in humans — Paper 2 · IGCSE Biology (9-1) 0970

20 Muscles are responsible for the ventilation of the lungs during breathing. Which row describes their action during the inspiration of air? diaphragm external internal muscles intercostal muscles intercostal muscles A contract contract relax B contract relax contract C relax contract relax D relax relax contract

1 marks

Answer: A

This question in 0970/21 May/June 2018

20 The graph shows changes in the volume of air in the lungs of a person at rest, over a period of 30 seconds. 2 volume of air in lungs 1 / dm3 0 0 30 time / s Which graph shows changes in the volume of air in the lungs of the same person immediately after they have done five minutes of vigorous exercise? A B 2 2 volume volume of air in of air in lungs 1 lungs 1 / dm3 / dm3 0 0 0 30 0 30 time / s time / s C D 2 2 volume volume of air in of air in lungs 1 lungs 1 / dm3 / dm3 0 0 0 30 0 30 time / s time / s

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2018

21 As we breathe out, … 1 … is … 2 … through the lungs. Which words correctly complete gaps 1 and 2? 1 2 A carbon dioxide excreted B carbon dioxide respired C oxygen excreted D oxygen respired

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2018

21 The diagram illustrates changes in air pressure taking place inside the lungs during a complete cycle of breathing. Atmospheric pressure is 101 kPa. At which point on the diagram are the ribs beginning to be lowered? B 102 C pressure in lungs 101 / kPa A D 100 time

1 marks

Answer: A

This question in 0970/21 May/June 2019

22 Potted plants are left for a week in a tank of water as shown. tank water soil permeable plant pot Why do the plants die? A The roots do not have enough oxygen. B The roots do not have enough water. C The roots have too much oxygen. D The roots have too much carbon dioxide.

1 marks

Answer: A

This question in 0970/21 May/June 2019

21 The diagram illustrates changes in air pressure taking place inside the lungs during a complete cycle of breathing. Atmospheric pressure is 101 kPa. At which point on the diagram are the ribs beginning to be lowered? B 102 C pressure in lungs 101 / kPa A D 100 time

1 marks

Answer: A

This question in 0970/22 May/June 2019

22 Which pathway is followed by air passing into the body? A larynx → trachea → bronchi → bronchioles → alveoli B larynx → trachea → bronchioles → bronchi → alveoli C trachea → larynx → bronchi → alveoli → bronchioles D trachea → larynx → bronchi → bronchioles → alveoli

1 marks

Answer: A

This question in 0970/22 May/June 2019

19 The diagram shows part of the human gas exchange system. to P Q R Which row identifies P, Q and R? P Q R A alveolus wall capillary wall vein B bronchiole alveolus wall capillary C capillary layer of moisture bronchiole D alveolus wall bronchiole capillary

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2019

20 What is the approximate percentage of oxygen contained in the air breathed out of the lungs? A 0% B 4% C 16% D 20%

1 marks

Answer: C

This question in 0970/21 May/June 2020

20 What is the site of gas exchange in humans? A nose B alveoli C bronchus D trachea

1 marks

Answer: B

This question in 0970/22 May/June 2020

20 The diagram shows some of the structures in a human lung. Where is the carbon dioxide concentration highest? from pulmonary artery C B to pulmonary vein D A

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2020

22 Which sequence of changes takes place when we breathe in? A diaphragm contracts  volume of thorax increases  pressure in lungs decreases B diaphragm contracts  volume of thorax increases  pressure in lungs increases C diaphragm relaxes  volume of thorax increases  pressure in lungs decreases D diaphragm relaxes  volume of thorax increases  pressure in lungs increases

1 marks

Answer: A

This question in 0970/21 May/June 2021

22 Which sequence of changes takes place when we breathe in? A diaphragm contracts  volume of thorax increases  pressure in lungs decreases B diaphragm contracts  volume of thorax increases  pressure in lungs increases C diaphragm relaxes  volume of thorax increases  pressure in lungs decreases D diaphragm relaxes  volume of thorax increases  pressure in lungs increases

1 marks

Answer: A

This question in 0970/22 May/June 2021

5 The diagram shows some cells. cilia cytoplasm nucleus Where are these cells found? A alimentary canal B blood C bronchus D plant roots

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2021

20 Which graph shows how the pressure inside the lungs changes when taking one breath in? A B pressure pressure atmospheric atmospheric pressure time pressure time C D pressure pressure atmospheric atmospheric pressure time pressure time

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2021

20 Which cells produce mucus? A ciliated cells B goblet cells C nerve cells D white blood cells

1 marks

Answer: B

This question in 0970/21 May/June 2022

21 Which row shows a change that occurs during ventilation? process thorax pressure thorax volume air movement A expiration decreases increases in B expiration increases decreases out C inspiration decreases increases out D inspiration increases decreases in

1 marks

Answer: B

This question in 0970/21 May/June 2022

5 By which process does oxygen move from a region of higher concentration in the alveoli to a region of lower concentration in the blood? A osmosis B breathing C diffusion D active transport

1 marks

Answer: C

This question in 0970/22 May/June 2022

20 What happens at the start of inspiration? internal external volume intercostal intercostal diaphragm of thorax muscles muscles A contract relax contracts increases B contract relax relaxes decreases C relax contract contracts increases D relax contract relaxes increases

1 marks

Answer: C

This question in 0970/22 May/June 2022

20 What is the approximate percentage of oxygen in expired air? A 0.04% B 4% C 16% D 21%

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2022

20 During inspiration, the processes listed take place. P volume of the thorax increases Q air rushes into the lungs R pressure in the thorax decreases S external intercostal muscles contract T diaphragm moves down, ribs move upwards and outwards What is the correct sequence for these processes? A Q → P → S → R → T B S → T → P → R → Q C Q → P → S → T → R D S → Q → R → P → T

1 marks

Answer: B

This question in 0970/21 May/June 2023

20 Different stages in the process of expiration are listed. 1 Rib cage moves downwards and inwards. 2 Volume of thorax decreases and pressure in lungs increases. 3 Air is pushed out of lungs. 4 Diaphragm and external intercostal muscles relax. What is the correct order of these stages? A 1 → 2 → 3 → 4 B 1 → 4 → 2 → 3 C 4 → 3 → 2 → 1 D 4 → 1 → 2 → 3

1 marks

Answer: D

This question in 0970/22 May/June 2023

21 What is the composition of expired air compared with inspired air? carbon dioxide oxygen water vapour A decreased increased increased B decreased decreased increased C increased decreased decreased D increased decreased increased

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2023

22 During exercise, receptors detect a change in the blood and cause the breathing rate to increase. Which change do the receptors detect and where are they found in the body? change detected location of receptors in the blood A carbon dioxide increases brain B carbon dioxide increases lung C carbon dioxide decreases brain D carbon dioxide decreases lung

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2023

23 What are the functions of the diaphragm and the cilia in the human gas exchange system? diaphragm cilia A contracts to cause breathing in carry mucus to the throat B contracts to cause breathing out trap bacteria from the air C relaxes to cause breathing in filter dust from the air D relaxes to cause breathing out produce mucus

1 marks

Answer: A

This question in 0970/21 May/June 2024

21 What causes air to enter the lungs? external intercostal air pressure volume of thorax muscles in thorax A contract decreases decreases B relax decreases increases C contract increases decreases D relax increases increases

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2024

18 The graph shows how the volume of air in lungs changes when a person is breathing at rest. X volume of air in lungs time Which processes are occurring to change the volume at the point marked X? A The diaphragm is relaxing and the external intercostal muscles are relaxing. B The diaphragm is contracting and the internal intercostal muscles are contracting. C The diaphragm is contracting and the internal intercostal muscles are relaxing. D The diaphragm is relaxing and the external intercostal muscles are contracting.

1 marks

Answer: A

This question in 0970/21 May/June 2025

6 Which row shows the conditions when diffusion of oxygen into the blood is fastest? alveolar surface concentration diffusion path area gradient distance A high high short B high low short C low high long D low low long

1 marks

Answer: A

This question in 0970/22 May/June 2025

20 The table shows the breathing rate and the average total volume of air breathed by a student when exercising for 20 minutes. breathing rate average total volume time / breaths per of air breathed / minutes minute / cm3 per minute 0 12 5 000 5 12 9 000 10 12 15 000 15 18 20 000 20 22 25 000 Which conclusion can be made from the data in the table about the effect of exercise on breathing? A Between 0 minutes and 10 minutes, there is no change to the depth of breathing. B Between 0 minutes and 10 minutes, the depth of breathing increases. C Between 10 minutes and 20 minutes, there is no change to the rate of breathing. D Between 15 minutes and 20 minutes, the depth of breathing decreases.

1 marks

Answer: B

This question in 0970/22 May/June 2025

16 Which row describes what happens when breathing in? external intercostal diaphragm muscles A contracts contract B contracts relax C relaxes contract D relaxes relax

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2025