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S5 Biology: Immune Response and Vaccines – Practice Paper 1 (Foundation, 10 Questions)
S5 Biology: Immune Response and Vaccines – Practice Paper 1 (Foundation, 10 Questions)
Paper one lays out the skeleton of the topic: how the three lines of defence divide the work, the difference between antigen and antibody, which cell secretes antibody, and where active immunity ends and passive begins. The numerical items need only one division or percentage, so fix the denominator first.
Quick answer The three lines run from skin and mucosa through non-specific defences to lymphocyte-based specific immunity; phagocytosis sits in the second line; plasma cells secrete antibody; a vaccine carries antigen; 10 days against 2 gives five times; 2% against 20% gives 90% efficacy.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 questions |
| Suggested time | about 20 minutes |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 2 · Error redo 2 |
| Chapter | Chapter: S5 Biology | Immune Response and Vaccines: Specific Immunity, Memory Cells and Herd Immunity |
| Level | Foundation |
02 Questions (10 items)
- FoundationWhat are the three lines of defence in the human body?
- FoundationPhagocytes engulfing a pathogen belong to which kind of defence, and why?
- FoundationWhat are an antigen and an antibody?
- IntermediateHow do active and passive immunity differ, and what is one example of each?
- IntermediateDoes a vaccine contain antigen or antibody?
- IntermediateWhat do memory cells do during a second infection?
- ChallengeAfter a first infection antibody peaks in about 10 days, but after a second infection in about 2 days: how many times faster is the secondary peak?
- ChallengeIn a vaccine trial 10 of 500 vaccinated people were infected while 40 of 200 unvaccinated controls were infected: what is the vaccine efficacy?
- Error redoError retry: a student says a vaccine injects antibodies so protection is instant. What is correct?
- Error redoError retry: a student calls antibodies in breast milk active immunity. What is the correct classification?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | The first is skin and mucous membranes; the second covers non-specific defences such as phagocytes, inflammation and interferon; the third is specific immunity run by B and T lymphocytes | The first two lines act the same way against any pathogen, and only the third recognises a particular antigen. |
| 2 | Non-specific defence, the second line, because they do not recognise a particular antigen and treat any invader the same way | Recognising a specific target is exactly what separates specific from non-specific defence. |
| 3 | An antigen is a foreign molecule, usually a protein or polysaccharide, that triggers a specific immune response; an antibody is a protein secreted by plasma cells that binds that antigen specifically | The antigen is what gets recognised and the antibody is what does the binding. |
| 4 | In active immunity the body makes its own antibodies and keeps memory cells, as in vaccination or natural infection; passive immunity receives ready-made antibodies with no memory cells, as with antibodies in breast milk or antivenom serum | The decisive difference is whether the body keeps its own memory cells. |
| 5 | Antigen: killed or attenuated pathogens, their toxins or surface proteins, not antibodies | A vaccine trains the body to make its own antibodies. |
| 6 | Memory B cells divide quickly into plasma cells and memory T cells are activated quickly, so the secondary response is faster and reaches a higher antibody level than the primary one | When the same antigen returns the body no longer has to start recognition from scratch. |
| 7 | Five times faster | 10 divided by 2 is 5, and memory cells account for the gap. |
| 8 | 90% | That is 2% against 20%, and (20% – 2%) divided by 20% gives 90%. |
| 9 | A vaccine injects antigen, so the body must make its own antibodies and memory cells and protection takes days; injecting antibodies directly is passive immunity, as with antivenom serum | A vaccine trains the body rather than substituting for it. |
| 10 | Naturally acquired passive immunity: the baby receives the mother antibodies directly, makes none itself and keeps no memory cells | Antibodies without memory cells of one own add up to passive immunity. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
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