Cambridge IGCSE Biology 0610: Diseases and immunity – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover topic 10, Diseases and immunity (section 10.1), of the Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028. Questions and parts marked (Extended) test Supplement content (immunity, vaccination and cholera), which only Extended candidates (Papers 2 and 4) need. Everything else is Core. Calculators may be used throughout.

Before you start, read the diseases and immunity study guide or the revision notes. Course pages: Cambridge IGCSE Biology hub and printable checklist.

Questions

1. Describe what is meant by:

(a) a pathogen [1] (b) a transmissible disease. [1]

2.

(a) State one way a pathogen can be transmitted by direct contact. [1] (b) State two ways a pathogen can be transmitted indirectly. [2]

3. Describe how each of the following protects the body against pathogens: the skin, hairs in the nose, stomach acid. [3]

4. Explain the importance of each of these in controlling the spread of disease:

(a) a clean water supply [2] (b) hygienic food preparation. [2]

5. In one region, 6400 cases of a viral disease were recorded in the year before a vaccination programme began. Five years later, 480 cases were recorded in a year.

(a) Calculate the percentage decrease in cases. Give your answer to one decimal place. [2] (b) (Extended) Explain how vaccinating a large proportion of the population reduced the number of cases. [3]

6. (Extended)

(a) Describe antibodies and how they act on pathogens. [3] (b) Explain why an antibody produced against one pathogen does not protect against a different pathogen. [2]

7. (Extended) Outline the process of vaccination. [3]

8. (Extended) A person receives two doses of a vaccine, several weeks apart. After the first dose, the antibody concentration in the blood peaks at 12 arbitrary units, 14 days after the injection. After the second dose, it peaks at 96 arbitrary units, 5 days after the injection.

(a) Calculate how many times greater the peak antibody concentration is after the second dose. [1] (b) Explain why the response to the second dose is faster and greater. [3]

9. (Extended)

(a) Explain what is meant by passive immunity. [2] (b) Explain the importance of breast-feeding for a newborn baby’s immunity. [2] (c) State why passive immunity does not give long-term protection. [1]

10. (Extended) Cholera is common after floods damage water supplies.

(a) Describe cholera in terms of its cause and how it is transmitted. [2] (b) Explain how cholera causes diarrhoea and dehydration. [4]

11. After heavy rain, sewage overflows into the wells that supply a village, and an outbreak of a waterborne disease follows.

(a) Explain two measures, other than vaccination, that would reduce the spread of the disease in the village. [4] (b) (Extended) A villager who has recovered from the disease does not become ill when the same pathogen enters her body the following year. Explain why. [3]

12. (Extended) Compare active immunity with passive immunity. [4]

Answers

1. (a) A disease-causing organism [1]. (b) A disease in which the pathogen can be passed from one host to another [1]. Examiner insight: “A germ” or “something that causes disease” is too vague; the mark needs the idea of an organism.

2. (a) Through blood or other body fluids (e.g. sharing needles) [1]. (b) Any two of: contaminated surfaces; food; animals; air [1] [1]. Examiner insight: Two clearly different routes are needed for both marks; “dirty food” and “unwashed food” are the same route and score only once.

3. Skin is a barrier that stops pathogens entering [1]; hairs in the nose trap pathogens (and dust) in breathed-in air [1]; stomach acid kills pathogens in food and drink [1]. Examiner insight: Each defence must be matched to its own action; a general statement such as “they all stop germs” scores nothing.

4. (a) Water is treated so pathogens are removed or killed [1], so people do not swallow pathogens and waterborne diseases are not passed on [1]. (b) Washing hands, keeping raw and cooked food apart, or cooking food thoroughly stops pathogens reaching or surviving in food [1], so pathogens are not eaten / passed to other people [1]. Examiner insight: “Explain” answers need the measure and the consequence for transmission; naming a measure alone earns only one of the two marks.

5. (a) (6400 − 480) ÷ 6400 × 100 [1] = 92.5% [1]. (b) Vaccinated people are immune, so they do not become infected [1]; the pathogen has fewer people it can be passed to [1], so transmission falls and unvaccinated people are also less likely to meet it [1]. Examiner insight: In (a) the answer must be given to the stated precision; 92% or 93% loses the accuracy mark when one decimal place is asked for.

6. (a) Antibodies are proteins [1] that bind to antigens [1]; this leads to direct destruction of the pathogen or marks it for destruction by phagocytes [1]. (b) Each pathogen has its own antigens with specific shapes [1]; antibodies have a complementary shape that fits only the specific antigen they were made against [1]. Examiner insight: “Same shape” is not accepted; the credited word is complementary.

7. Weakened pathogens or their antigens are put into the body [1]; the antigens stimulate lymphocytes to produce antibodies [1]; memory cells are produced, giving long-term immunity [1]. Examiner insight: Missing the memory cells loses the third mark, and saying the vaccine “contains antibodies” is a contradiction that can cost the first.

8. (a) 96 ÷ 12 = 8 times [1]. (b) The first dose produced memory cells [1]; on the second dose, memory cells recognise the antigen [1] and antibodies are made more quickly and in larger quantities [1]. Examiner insight: Data-linked marks usually need you to use the figures given; quoting “5 days instead of 14” supports the word “faster”.

9. (a) Short-term defence against a pathogen [1] by antibodies acquired from another individual (e.g. across the placenta) [1]. (b) Breast milk contains the mother’s antibodies [1], which give the baby passive immunity while its own immune system develops [1]. (c) No memory cells are produced [1]. Examiner insight: A definition of passive immunity that omits “from another individual” does not distinguish it from active immunity and loses that mark.

10. (a) Cholera is caused by a bacterium [1] and is transmitted in contaminated water [1]. (b) The bacterium produces a toxin [1] that causes chloride ions to be secreted into the small intestine [1]; water moves into the gut by osmosis [1], causing diarrhoea, dehydration and loss of ions from the blood [1]. Examiner insight: The osmosis mark needs the word osmosis and the direction (into the gut); “the toxin makes water leave the body” misses two marks.

11. (a) Any two measures, each with its explanation: Provide clean (treated or boiled) water [1], so pathogens are killed before people drink it [1]. Treat or safely dispose of sewage [1], so pathogens in faeces cannot reach the water supply [1]. (Also creditworthy as one of the two: good personal hygiene / handwashing, which removes pathogens before they reach the mouth or food.) (b) During the first infection her lymphocytes made antibodies and memory cells [1]; memory cells recognise the pathogen’s antigens when it returns [1] and antibodies are made quickly, destroying the pathogen before she becomes ill; this is active immunity [1]. Examiner insight: In (a) each explanation mark depends on its measure; two measures with no explanation score 2 out of 4, not 4.

12. Active immunity uses antibodies made by the person’s own lymphocytes; passive uses antibodies from another individual [1]. Active is gained by infection or vaccination; passive across the placenta or in breast milk [1]. Memory cells are produced in active but not passive immunity [1]. Active is long-term; passive is short-term [1]. Examiner insight: “Compare” needs both sides of each point in the same sentence; a paragraph on active followed by a paragraph on passive may only score half.

Where marks are usually lost

• Describing a pathogen without the word organism.
• Naming a public-health measure but not saying which transmission route it blocks.
• Saying mucus kills pathogens instead of trapping them.
• Writing “same shape” rather than “complementary shape” for antibody and antigen.
• Leaving memory cells out of the vaccination outline.
• Saying vaccines contain antibodies.
• Omitting chloride ions or osmosis from the cholera mechanism.
• Rounding a percentage to the wrong precision when a number of decimal places is specified.
• Writing separate descriptions instead of direct comparisons in “compare” questions.

Next steps

• Recap with the diseases and immunity revision notes.
• Re-read any weak section in the study guide.
• Revisit blood cells in the transport in animals practice questions.
• Take the 0610 Core diagnostic or 0610 Extended diagnostic.
• Browse the Cambridge IGCSE Biology hub and tick off the printable checklist.
• Book a free trial class.

Official syllabus

Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 (Version 3), section 10 Diseases and immunity. Published by Cambridge University Press & Assessment.