1 (a) The boxes on the left show characteristics of living organisms. The boxes on the right show some definitions of characteristics. Draw one straight line from each characteristic to its correct definition. characteristic definition excretion sensitivity nutrition responding to change removing waste from the body permanent increase in size taking in materials for energy [3] (b) Respiration is another characteristic of living organisms. Aerobic respiration needs oxygen. Complete these sentences to describe how oxygen from the air gets into the blood of a human. As we breathe in, air passes from our bronchioles into the … of the lungs. The oxygen in this air then moves into red blood cells by the process of … . [2] (c) Organisms are made up of cells. Fig. 1.1 is a photomicrograph of an animal cell. X Fig. 1.1 (i) Identify the part labelled X in Fig. 1.1. … [1] (ii) State two pieces of evidence from the cell in Fig. 1.1 that show it is not a plant cell. 1 … 2 … [2] [Total: 8]

1(a) responding to change excretion removing waste from the body nutrition permanent increases in size sensitivity taking in materials for energy ;;; 3 1(b) alveoli ; diffusion ; 2 1(c)(i) nucleus ; 1 1(c)(ii) any two from: no cell wall ; no chloroplasts ; no (large) vacuole ; 2 (a) To earn marks, you must draw a straight line from each characteristic on the left to its correct definition on the right. (b) You need to correctly identify 'alveoli' as the structure air passes into and 'diffusion' as the process by which oxygen moves into red blood cells. (c)(i) You must correctly identify the labelled part X as the 'nucleus'. (c)(ii) You need to state two distinct features that are absent in the animal cell shown but present in a plant cell, such as no cell wall, no chloroplasts, or no large vacuole.

1 (a) Fig. 1.1 is a diagram of the circulatory system in humans. Y X lungs heart body tissues Fig. 1.1 (i) The arrows show the direction of blood flow through the blood vessels. Blood vessels X and Y are two of the main blood vessels attached to the heart. Identify blood vessels X and Y shown in Fig. 1.1. X … Y … [2] (ii) State the function of the heart. … [1] (iii) Circle the name of the tube that connects the lungs to the nose and mouth. alveoli bronchi bronchiole larynx trachea [1] (b) Complete these sentences about the blood. Choose words from the list. Each word may be used once, more than once or not at all. chlorophyll glucose haemoglobin nitrogen oxygen phagocytosis egestion There are two types of blood cells, red blood cells and white blood cells. Red blood cells transport the gas, … . The gas binds to a chemical in red blood cells called … . White blood cells produce antibodies. White blood cells are also involved in the process of … . [3] (c) Fig. 1.2 shows the pulse rate of a person doing different activities. 0 20 40 60 80 100 120 140 160 pulse rate / beats per minute sitting standing walking running slowly jumping running fast type of activity Fig. 1.2 (i) Place a tick (3) in one box to show the activity that results in a pulse rate of between 120 and 140 beats per minute. jumping sitting running fast standing running slowly walking [1] (ii) Calculate the difference in pulse rate between sitting and running fast. pulse rate sitting = … beats per minute pulse rate running fast = … beats per minute difference in pulse rate = … beats per minute [2] (iii) Describe how the person’s breathing is different when walking compared to jumping. … … [2] [Total: 12]

1(a)(i) aorta ; vena cava ; 2 1(a)(ii) pump blood ; 1 1(a)(iii) trachea ; 1 1(b) oxygen ; haemoglobin ; phagocytosis ; 3 1(c)(i) running slowly box ticked ; 1 1(c)(ii) reading values from graph 60 and 150 ; correct subtraction / 90 ; 2 1(c)(iii) lower breathing rate / AW ; lesser depth of breathing / AW ; 2

4 (a) Fig. 4.1 is a diagram of the gas exchange system in a human. P Fig. 4.1 (i) Identify the part labelled P in Fig. 4.1. … [1] (ii) On Fig. 4.1, draw a label line and the letter L to identify the larynx. [1] (b) Expired air contains a different percentage of carbon dioxide to inspired air. State and explain this difference. difference … … explanation … … [2] (c) Fig. 4.2 shows cells that line the airways of a non-smoker and a smoker. non-smoker smoker mucus ciliated cell cilia goblet cell Fig. 4.2 Explain how smoking tobacco affects the function of the cells shown in Fig. 4.2. Use the information in Fig. 4.2 in your answer. … … … … … … [3] [Total: 7]

4(a)(i) diaphragm ; 1 4(a)(ii) larynx labelled ; 1 4(b) difference: more carbon dioxide in expired air ; explanation: because produced in respiration ; 2 4(c) any three from: cilia are, damaged / shorter ; (goblet cells make) more mucus ; pathogens / particles, trapped in the mucus ; idea that it is harder (for cilia) to move the mucus ; idea that, pathogens / particles, are not removed (easily) from the airways ; 3

7 (a) Fig. 7.1 is a diagram of the gas exchange system in humans. Fig. 7.1 (i) On Fig. 7.1 draw a label line and the letter B to identify a bronchus. [1] (ii) State two features of the alveoli that make them an efficient gas exchange surface. 1 … … 2 … … [2] (b) The pulse rate and breathing rate of two people are measured before and after activity. Fig. 7.2 shows a bar chart of the results. 0 person 1 before activity person 1 after activity person 2 before activity person 2 after activity 40 80 pulse rate / beats per minute breathing rate / breaths per minute 120 160 20 60 100 140 0 40 80 120 160 pulse rate Key breathing rate 20 60 100 140 Fig. 7.2 (i) Compare the increase in breathing rates of the two people. … … [1] (ii) Table 7.1 shows the pulse rate data and percentage increase in pulse rate for person 1. Complete Table 7.1 to show the pulse rate data and percentage increase in pulse rate for person 2. Table 7.1 person pulse rate before activity / beats per minute pulse rate after activity / beats per minute change in pulse rate / beats per minute percentage increase in pulse rate 1 80 140 60 75 2 [2] (c) One reason why breathing rate increases during activity is the need for more oxygen. Explain one other reason why breathing rate increases during activity. … … … … [2] [Total: 8]

7(a)(i) bronchus labelled anywhere in shaded area ; 1 7(a)(ii) any two from: large surface area ; good blood supply ; thin walls ; good ventilation ; AVP ; 2 7(b)(i) person 1 has a higher increase in breathing rate ORA ; 1 7(b)(ii) 70 AND 130 AND 60 ; 86 ; 2 7(c) any two from: increased respiration ; cause increase in carbon dioxide levels (in the blood) ; removes more carbon dioxide (from the blood) / removes carbon dioxide faster ; AVP ; 2

Cambridge IGCSE Combined Science · 0653

IGCSE Combined Science (0653) Gas exchange in humans past paper questions

Revise IGCSE Combined Science (0653) — Gas exchange in humans with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

83 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

Gas exchange in humans in IGCSE Combined Science 0653 exams, 2020–2025

Across 2020–2025, Gas exchange in humans accounted for 82 questions worth 267 marks in Cambridge IGCSE Combined Science (0653) papers.

By year
Year	Questions	Marks
2020	10	49
2021	15	46
2022	20	59
2023	16	62
2024	16	39
2025	5	12

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B11.1 Gas exchange in humans209 marks

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Paper 1 · 25 qs
Paper 2 · 33 qs
Paper 3 · 9 qs
Paper 4 · 15 qs

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2021 May/Jun · Paper 3 · Q1 · 8 marks
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2021 Oct/Nov · Paper 3 · Q1 · 12 marks
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2021 Oct/Nov · Paper 4 · Q4 · 7 marks
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2021 Oct/Nov · Paper 4 · Q7 · 8 marks
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2021 May/Jun · Paper 1 · Q7 · 1 mark
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Mark scheme — 2021 Paper 1 Q7
Answer: D
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