Disease, Gas Exchange & Respiration: IGCSE Biology questions and answers
10 free IGCSE Biology Disease, Gas Exchange & Respiration questions written in the style of Cambridge Biology papers, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers Diseases & immunity, Gas exchange, Respiration, Excretion. Work through the questions below, then generate a full Disease, Gas Exchange & Respiration paper with a fresh set every time.
Disease, gas exchange & respiration practice questions
Question 1Structured · 6 marksA* challenge
The kidneys filter the blood and produce urine.
(a)
Name two substances found in urine.
[2]
(b)
Explain why glucose is not normally found in urine.
[2]
(c)
Explain how urea is formed.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
urea; water; salts
Any 2 of: urea; water; excess salts (ions) B2
2
(b)
reabsorbed in nephron
glucose is filtered but then all reabsorbed back into the blood (in the nephron tubule) B2
2
(c)
deamination of excess amino acids in liver
excess amino acids are deaminated in the liver B1 the nitrogen-containing part forms urea B1
2
Question 2Structured · 4 marksA* challenge
Kidney failure can be treated by dialysis.
(a)
Explain how a dialysis machine removes urea from the blood.
[3]
(b)
Explain why the dialysis fluid contains glucose at the same concentration as blood.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
urea diffuses into dialysis fluid, no urea in fluid
blood passes alongside dialysis fluid separated by a partially permeable membrane B1 the fluid contains no urea B1 urea diffuses out of the blood B1
3
(b)
no glucose lost
so that glucose does not diffuse out of the blood B1
1
Question 3Structured · 4 marksA* challenge
Cholera is caused by a bacterium in contaminated water.
(a)
Explain how cholera causes diarrhoea and dehydration.
[3]
(b)
State one way of preventing the spread of cholera.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
toxin; chloride ions secreted; water follows by osmosis
the bacterium produces a toxin B1 chloride ions are secreted into the small intestine B1 water moves out of the blood by osmosis, causing diarrhoea and dehydration B1
3
(b)
clean water; sewage treatment
clean water supply / sewage treatment / hygiene B1
1
Question 4Structured · 6 marksA* challenge
Yeast can respire aerobically or anaerobically.
(a)
Write the word equation for anaerobic respiration in yeast.
[2]
(b)
Give one use of this reaction in industry.
[1]
(c)
Describe how you would investigate the effect of temperature on the rate of respiration of yeast.
[3]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
glucose → ethanol + carbon dioxide
glucose → ethanol + carbon dioxide B2
2
(b)
bread / alcohol production
bread-making (CO₂ raises dough) or brewing (ethanol) B1
1
(c)
water baths; count bubbles/measure gas; same conditions
yeast and sugar solution in water baths at different temperatures B1 measure rate by counting bubbles / volume of CO₂ per minute B1 keep concentration and volume constant B1
3
Question 5Structured · 4 marks
Limewater can be used to compare the carbon dioxide in inspired and expired air.
(a)
Describe the result of the test.
[2]
(b)
Explain why the trachea is lined with ciliated cells and goblet cells.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
expired turns milky faster
limewater turns milky/cloudy B1 faster with expired air (more CO₂) B1
2
(b)
mucus traps pathogens; cilia move it away
goblet cells make mucus that traps dust and pathogens B1 cilia beat to move mucus up and away from the lungs B1
2
Question 6Structured · 5 marks
Respiration releases energy in all living cells.
(a)
Write the word equation for aerobic respiration.
[2]
(b)
State three uses of the energy released by respiration in humans.
[3]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
glucose + oxygen → carbon dioxide + water
glucose + oxygen B1 → carbon dioxide + water B1
2
(b)
muscle contraction; protein synthesis; cell division; active transport; growth; nerve impulses; body temperature
Any 3 of: any three: muscle contraction; protein synthesis; cell division; active transport; growth; passage of nerve impulses; maintenance of body temperature B3
3
Question 7Structured · 14 marks
This question is about disease and the body’s defences.
(a)
State what is meant by a pathogen and by a transmissible disease.
[2]
(b)
Describe how the body defends itself against pathogens before they enter the blood.
[3]
A person is vaccinated against a disease. Two months later they are exposed to the pathogen.
(c)(i)
Describe and explain how vaccination provides protection against the disease.
[5]
(ii)
Explain why passive immunity from antibodies given by injection lasts only a short time.
[2]
(d)
State two ways in which phagocytes and lymphocytes protect the body.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
disease-causing organism; disease where pathogen passed between hosts
pathogen: a disease-causing organism B1 transmissible disease: a disease in which the pathogen can be passed from one host to another B1
2
(b)
skin barrier; hairs in nose; mucus traps; stomach acid kills
skin acts as a barrier B1 hairs in the nose / mucus traps pathogens B1 stomach acid kills pathogens B1
3
(c)(i)
weakened pathogen / antigens; lymphocytes make antibodies; memory cells; faster larger secondary response; pathogen destroyed before symptoms
vaccine contains weakened / dead pathogens or their antigens B1 lymphocytes produce specific antibodies B1 memory cells are produced B1 on exposure, memory cells make antibodies more quickly and in larger amounts B1 pathogens are destroyed before symptoms develop B1
5
(ii)
antibodies broken down; no memory cells made
the antibodies are broken down (not replaced) B1 no memory cells are produced B1
2
(d)
phagocytes engulf and digest pathogens; lymphocytes make antibodies
phagocytes engulf and digest pathogens (phagocytosis) B1 lymphocytes produce antibodies B1
2
Question 8Structured · 3 marks
The lungs are protected from pathogens and particles.
(a)
Describe the role of mucus and cilia.
[2]
(b)
Explain why the trachea has rings of cartilage.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
mucus traps; cilia sweep up
mucus traps pathogens and dust B1 cilia beat to move the mucus up to the throat B1
2
(b)
keeps airway open
to keep the airway open during breathing B1
1
Question 9Structured · 4 marks
The spread of disease can be controlled.
(a)
Explain how each method reduces the spread of disease: hygienic food preparation; good personal hygiene; waste disposal.
[3]
(b)
Explain why antibodies are specific.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
kills/removes pathogens; stops transmission
food: prevents pathogens reaching food/kills them by cooking B1 hygiene: washing hands removes pathogens B1 waste disposal: removes breeding grounds for vectors/pathogens B1
3
(b)
shape complementary to antigen
each antibody has a shape that fits only one antigen B1
1
Question 10Structured · 11 marks
A student counts the number of times a fish opens and closes its gill covers in 30 seconds, at different water temperatures. Table 10.1 shows the mean results.
temperature / °C
10
15
20
25
30
gill movements in 30 s
30
48
82
123
184
Table 10.1
(a)
Calculate the rate of gill movements per minute at 20 °C.
[1]
(b)
Describe the relationship between temperature and the rate of gill movements.
[2]
(c)
Fish are ectotherms (their body temperature matches the water). Explain why the rate of gill movements increases with temperature.
[3]
(d)
Suggest one variable, other than temperature, that the student should keep constant, and explain why.
[2]
(e)
Suggest why the student recorded the movements for 30 s three times at each temperature.
[1]
(f)
State two features of gills that make them efficient gas exchange surfaces.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
164 per minute
82 × 2 = 164 B1
1
(b)
rate increases as temperature increases; data quote
as temperature increases the rate of gill movements increases B1 data quote, e.g. from 30 to 184 movements per 30 s between 10 °C and 30 °C / more than doubles for every 10 °C rise B1
2
(c)
enzymes faster; more respiration; more O₂ needed
enzymes in the fish’s cells are more active at higher temperatures B1 so the rate of respiration increases B1 more oxygen must be absorbed / more CO₂ removed, so ventilation increases B1
3
(d)
size/species of fish; oxygen content; time acclimatised
e.g. the same fish / size of fish, the oxygen concentration of the water, time left to adjust to each temperature B1 because it also affects the rate of respiration / ventilation B1
2
(e)
calculate a mean / reliability
to calculate a mean and reduce the effect of anomalous counts B1
1
(f)
large surface area (filaments, lamellae); thin; good blood supply
Any 2 of: large surface area (many filaments / lamellae); thin walls / short diffusion distance; good blood supply B2
What is in IGCSE Biology Disease, Gas Exchange & Respiration?
In the 0610 syllabus, Disease, Gas Exchange & Respiration covers Diseases & immunity, Gas exchange, Respiration, Excretion.
Where can I get Disease, Gas Exchange & Respiration questions with mark schemes?
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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in