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The immune system: OCR A‑Level Biology B questions

Every OCR A-Level Biology B exam question on 3.2.2 The immune system, 2016–2025, with its mark scheme and examiner’s report.

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1,889 questions

  1. Q32(b)(i)

    June 2025 · Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2025 Paper 1, question 32(b)(i): Name the type of immunity acquired by breastfeeding. [1]

  2. Q32(c)(i)

    June 2025 · Paper 1

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2025 Paper 1, question 32(c)(i): Outline a method used to test for HIV infection. [2]

  3. Q32(c)(ii)

    June 2025 · Paper 1

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2025 Paper 1, question 32(c)(ii): Calculate the mean rate of decrease in HIV antibody concentration, per day, for the first year after being exposed to HIV. Give your answer to 2 significant fig

  4. Q32(c)(iii)

    June 2025 · Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2025 Paper 1, question 32(c)(iii): Sketch a line on the graph to suggest the expected HIV antibody concentration for an HIV-exposed baby who is not infected with HIV at birth but was infected dur

  5. Q32(c)(iv)

    June 2025 · Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2025 Paper 1, question 32(c)(iv): Research shows that HIV testing cannot be used to definitively diagnose infection in young babies and that babies under 18 months of age may record a false-posi

  6. Q17

    June 2025 · AS Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2025 AS Paper 1, question 17: What would occur in a non-specific response to pathogens? A Clonal expansion B Clonal selection C Inflammation D Production of antibodies Your answer [1]

  7. Q28

    June 2024 · Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2024 Paper 1, question 28: Which of the options is not a method used by antibodies to destroy pathogens? A Agglutination B Coagulation C Neutralisation D Opsonisation Your answer [1]

  8. Q1(d)(i)

    June 2024 · Paper 2

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2024 Paper 2, question 1(d)(i): State what treatment the mice in the control group would have received in both exper

  9. Q1(d)(ii)

    June 2024 · Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 Paper 2, question 1(d)(ii): Calculate how many times more T killer memory cells were present in the spleen of control mice compared with the cornea of control mice. Give your answer in sta

  10. Q1(d)(iii)

    June 2024 · Paper 2

    3 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 Paper 2, question 1(d)(iii): The researchers concluded that the corneas of mice four weeks after infection with HSV contained tissue-resident T helper memory cells and tissue-resident T kil

  11. Q18

    June 2024 · AS Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 1, question 18: Which statement about an allergic response is correct? A Allergens release antigen-specific antibodies. B Mast cells release antigen-specific antibodies. C Mast

  12. Q5(a)(i)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(a)(i): Explain how a horse produces antibodies when it is given snake venom. [2]

  13. Q5(a)(ii)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(a)(ii): The horses produce a small quantity of antibody the first time they are used to produce antivenom. When they are given doses of venom on future occasions they p

  14. Q5(a)(iii)

    June 2024 · AS Paper 2

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(a)(iii): The dose of venom given to different horses is calculated in μg kg–1 of body mass. Suggest why the dose is calculated based on the horse’s body mass. [1]

  15. Q5(b)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(b): Daboia siamensis is a species of snake native to Southeast Asia. To produce antivenom for Daboia siamensis, a 600 kg horse is given a dose of 3.5 μg kg–1 of bod

  16. Q5(c)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(c): There is a small risk that patients might have an allergic reaction to antivenom if they are given a particular antivenom more than once. Explain what causes an

  17. Q5(d)(i)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(d)(i): Suggest how antivenom acts on cytotoxin to prevent damage to the cell. [2]

  18. Q5(d)(iii)

    June 2024 · AS Paper 2

    2 marks3.2.2 The immune system
    The whole paper ↗
    June 2024 AS Paper 2, question 5(d)(iii): Cytotoxin can cause the death of T lymphocytes. Explain why even if a patient receives the correct antivenom immediately after a snake bite, they can be more vu

  19. Q20

    June 2023 · Paper 1

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2023 Paper 1, question 20: Which of the statements about allergic reactions is correct? A Allergens bind to antigens on mast cells. B Allergens trigger a primary immune response. C Allerg

  20. Q1(a)(i)

    June 2023 · Paper 2

    1 mark3.2.2 The immune system
    The whole paper ↗
    June 2023 Paper 2, question 1(a)(i): State what is meant by the term antigen. [1]
All 76 questions on The immune system, as a list
  1. June 2025, Paper 1, Q32(b)(i) (1 mark): Name the type of immunity acquired by breastfeeding. [1]
  2. June 2025, Paper 1, Q32(c)(i) (2 marks): Outline a method used to test for HIV infection. [2]
  3. June 2025, Paper 1, Q32(c)(ii) (2 marks): Calculate the mean rate of decrease in HIV antibody concentration, per day, for the first year after being exposed to HIV. Give your answer to 2 significant fig
  4. June 2025, Paper 1, Q32(c)(iii) (1 mark): Sketch a line on the graph to suggest the expected HIV antibody concentration for an HIV-exposed baby who is not infected with HIV at birth but was infected dur
  5. June 2025, Paper 1, Q32(c)(iv) (1 mark): Research shows that HIV testing cannot be used to definitively diagnose infection in young babies and that babies under 18 months of age may record a false-posi
  6. June 2025, AS Paper 1, Q17 (1 mark): What would occur in a non-specific response to pathogens? A Clonal expansion B Clonal selection C Inflammation D Production of antibodies Your answer [1]
  7. June 2024, Paper 1, Q28 (1 mark): Which of the options is not a method used by antibodies to destroy pathogens? A Agglutination B Coagulation C Neutralisation D Opsonisation Your answer [1]
  8. June 2024, Paper 2, Q1(d)(i) (1 mark): State what treatment the mice in the control group would have received in both exper
  9. June 2024, Paper 2, Q1(d)(ii) (2 marks): Calculate how many times more T killer memory cells were present in the spleen of control mice compared with the cornea of control mice. Give your answer in sta
  10. June 2024, Paper 2, Q1(d)(iii) (3 marks): The researchers concluded that the corneas of mice four weeks after infection with HSV contained tissue-resident T helper memory cells and tissue-resident T kil
  11. June 2024, AS Paper 1, Q18 (1 mark): Which statement about an allergic response is correct? A Allergens release antigen-specific antibodies. B Mast cells release antigen-specific antibodies. C Mast
  12. June 2024, AS Paper 2, Q5(a)(i) (2 marks): Explain how a horse produces antibodies when it is given snake venom. [2]
  13. June 2024, AS Paper 2, Q5(a)(ii) (2 marks): The horses produce a small quantity of antibody the first time they are used to produce antivenom. When they are given doses of venom on future occasions they p
  14. June 2024, AS Paper 2, Q5(a)(iii) (1 mark): The dose of venom given to different horses is calculated in μg kg–1 of body mass. Suggest why the dose is calculated based on the horse’s body mass. [1]
  15. June 2024, AS Paper 2, Q5(b) (2 marks): Daboia siamensis is a species of snake native to Southeast Asia. To produce antivenom for Daboia siamensis, a 600 kg horse is given a dose of 3.5 μg kg–1 of bod
  16. June 2024, AS Paper 2, Q5(c) (2 marks): There is a small risk that patients might have an allergic reaction to antivenom if they are given a particular antivenom more than once. Explain what causes an
  17. June 2024, AS Paper 2, Q5(d)(i) (2 marks): Suggest how antivenom acts on cytotoxin to prevent damage to the cell. [2]
  18. June 2024, AS Paper 2, Q5(d)(iii) (2 marks): Cytotoxin can cause the death of T lymphocytes. Explain why even if a patient receives the correct antivenom immediately after a snake bite, they can be more vu
  19. June 2023, Paper 1, Q20 (1 mark): Which of the statements about allergic reactions is correct? A Allergens bind to antigens on mast cells. B Allergens trigger a primary immune response. C Allerg
  20. June 2023, Paper 2, Q1(a)(i) (1 mark): State what is meant by the term antigen. [1]
  21. June 2023, Paper 2, Q1(a)(ii) (2 marks): Scientists can combine antibody fragments using phage display to produce many different antibodies, each specific to a different antigen. Using the abbreviation
  22. June 2023, Paper 2, Q1(a)(iii) (1 mark): The B cell receptor is an IgG molecule with the same structure as the human IgG shown in Fig. 1 in the Advance Notice Article. Use an abbreviation from Fig. 1 t
  23. June 2023, Paper 2, Q1(b)(i) (2 marks): Explain why mouse monoclonal antibodies (mAbs) have been largely replaced as therapeutic antibodies by humanised or fully human mAbs. [2]
  24. June 2023, Paper 2, Q1(b)(ii) (2 marks): Explain why the Fab and scFv antibody fragments shown in Fig. 1 are effective as neutralizing or agglutinating antibodies but are less effective as opsonins or
  25. June 2023, Paper 2, Q1(d) (6 marks): This question is based on the Advance Notice Article ‘Development of therapeutic antibodies for the treatment of disease’. (d)* Describe the role of T and B lym
  26. June 2023, Paper 2, Q3(a)(iii) (2 marks): Describe two effects of cytokine release by macrophages. [2]
  27. June 2022, AS Paper 1, Q5 (1 mark): The diphtheria vaccine contains a bacterial toxin that results in the production of antibodies when injected into the body. Which type of immunity is provided b
  28. June 2022, AS Paper 1, Q7 (1 mark): The sentences below are about an immune response. During a 1 immune response, clonal expansion is faster. More plasma cells are produced by 2 , which results in
  29. June 2022, AS Paper 1, Q25(c) (3 marks): Neutrophils are blood cells that have a role in the non-specific immune response. Outline the mode of action of neutrophils. [3]
  30. November 2021, Paper 1, Q9 (1 mark): A 45-year-old patient was admitted to hospital with a lung infection. The patient was tested for tuberculosis (TB) using a Mantoux skin test. The Mantoux skin t
  31. November 2021, Paper 1, Q10 (1 mark): Diphtheria is a bacterial disease of humans that can be treated by vaccination using an antitoxin. The antitoxin is a solution of antibodies specific to the ant
  32. November 2021, Paper 1, Q13 (1 mark): Which of the options, A to D, is formed by the fusion of a cell membrane around a microorganism? A bleb B phagosome C vacuole D virus Your answer [1]
  33. November 2021, Paper 2, Q1(d)(i) (2 marks): Explain how immunological and genetic factors would allow a population of wild rabbits to become more resistant to infection by MYXV. [2]
  34. November 2021, Paper 2, Q7(a) (4 marks): Immunity can be categorised as • active or passive • natural or artificial. Complete the following table by putting ticks (✓) in the correct boxes to show wheth
  35. November 2021, Paper 2, Q7(b)(i) (2 marks): Name a statistical test the scientists could have used to compare the results of the two groups. Give a reason for your choice. [2]
  36. November 2021, Paper 2, Q7(b)(ii) (2 marks): State which group of offspring showed more AAD. Give a reason for your choice. [2]
  37. November 2021, Paper 2, Q7(b)(iii) (3 marks): The statistical analysis showed there was a significant difference in the concentrations of IgE antibodies in the two groups. Breastfeeding is associated with a
  38. November 2021, AS Paper 1, Q9 (1 mark): Clonal expansion occurs during the specific immune response. Which of the statements, A to D, is a description of clonal expansion? A B lymphocytes differentiat
  39. November 2021, AS Paper 1, Q13 (1 mark): The Mantoux test is used to test for Tuberculosis (TB). Which of the statements, A to D, about the Mantoux test is true? A People who have a strong positive rea
  40. November 2021, AS Paper 2, Q4(c)(i) (2 marks): HIV infections can be detected by two different tests. • A nucleic acid test can detect HIV infection 10 to 33 days after an exposure. • An antigen blood test c
  41. November 2021, AS Paper 2, Q4(c)(ii) (3 marks): The time taken for HIV to replicate is called one HIV life cycle. It takes 16 hours to go through one HIV life cycle. After one HIV life cycle, 300 viruses are
  42. November 2021, AS Paper 2, Q4(d)(i) (2 marks): Name the region of the antibody labelled W and state its function. Name Function [2]
  43. November 2021, AS Paper 2, Q4(d)(ii) (2 marks): Explain how the structure of the region labelled V allows the antibody to bind to different antigens on different viruses. [2]
  44. November 2020, Paper 1, Q20 (1 mark): Which of the cell types, A to D, initiates the secondary immune response? A helper T cell B memory B cell C plasma B cell D regulatory T cell Your answer [1]
  45. November 2020, Paper 1, Q31(b)(i) (2 marks): Pregnancy testing involves the use of antibodies. The antigen-binding site of an antibody recognises its antigen. Describe the structure of the antigen-binding
  46. November 2020, AS Paper 1, Q18 (1 mark): The diagram below shows an antibody molecule. bond X Which of the bonds, A to D, is the type of bond labelled X in the diagram? A peptide B hydrogen C ionic D d
  47. November 2020, AS Paper 1, Q22(a)(i) (2 marks): Explain what is meant by an allergic response. [2]
  48. November 2020, AS Paper 1, Q22(a)(ii) (1 mark): Five allergens, including cow’s milk and pollen, were used during the study to test for sensitivity. Name two other allergens that could have been used to trigg
  49. June 2019, Paper 1, Q16 (1 mark): An initial exposure to an allergen prepares the immune system for a rapid response upon repeated exposure. This process is known as sensitisation. Which of the
  50. June 2019, Paper 2, Q2(c) (6 marks): Antimicrobial peptides (AMPs) are peptides found in animals and plants that destroy a wide range of pathogenic bacteria, fungi and viruses. The α–defensins are
  51. June 2019, AS Paper 1, Q17 (1 mark): Which of the options, A to D, are molecules that enhance phagocytosis by marking antigens during an immune response? A cytokines B agglutinins C anti-toxins D o
  52. June 2019, AS Paper 1, Q18 (1 mark): Vaccination can provide immunity to infectious diseases. The graph below shows an immune response for a person who has been vaccinated against an infectious dis
  53. June 2019, AS Paper 1, Q25(b)(i) (3 marks): Describe examples of two types of natural immunity. [3]
  54. June 2019, AS Paper 1, Q25(b)(ii) (3 marks): Studies have shown the presence of memory B lymphocytes in recipients of the HPV vaccine eight years after it was administered. Outline the role of memory B lym
  55. June 2019, AS Paper 2, Q6(d) (4 marks): In young children, the flu vaccine can be administered using a nasal spray containing antigens. Explain how these antigens in the nasal spray cause an increase
  56. June 2018, Paper 3, Q4(a)(i) (2 marks): Explain how this percentage error could lead to incorrect decisions about whether a BCG vaccination is needed. [2]
  57. June 2018, Paper 3, Q4(a)(ii) (2 marks): A health professional measures the diameter of the induration using a ruler marked in millimetres. Suggest one way this method for measuring indurations could b
  58. June 2018, Paper 3, Q4(b) (6 marks): The Mantoux test is used to check if a person is immune to tuberculosis (TB) to decide whether they need a BCG vaccination. A red inflamed lump (induration) may
  59. June 2018, AS Paper 1, Q6 (1 mark): The photomicrographs show different types of leucocyte (white blood cell). leucocyte A leucocyte B leucocyte C leucocyte D Which of the leucocytes, A to D, can
  60. June 2018, AS Paper 1, Q25(a) (4 marks): Complete the passage below about an allergic reaction using the most appropriate words or phrases. Exposure to an allergen triggers the production of IgE antibo
  61. June 2018, AS Paper 2, Q4(a) (4 marks): Describe and explain the pattern in the data shown in Fig. 4. [4]
  62. June 2018, AS Paper 2, Q4(c) (2 marks): Complete the table below by indicating which of the statements about different types of immunity are true (T) or false (F). Statement True (T) or False (F) An i
  63. June 2018, AS Paper 2, Q4(d) (6 marks): Following the injection of a vaccine the antibody concentration in the blood changes. Fig. 4 shows the concentration of antibody in the blood of an individual f
  64. June 2017, Paper 1, Q20 (1 mark): The general structure of an antibody is shown below. Three features are labelled X, Y and Z. X Y Z Which of the statements, A to D, is correct? A X is a disulfi
  65. June 2017, Paper 1, Q34(a)(i) (2 marks): Statements A to F below summarise, in random order, the stages of an immune response to the virus. A T helper cells are activated and divide by mitosis. B B cel
  66. June 2017, Paper 1, Q34(a)(ii) (1 mark): Describe the role of T killer cells in the immune response to HPV. [1]
  67. June 2017, Paper 1, Q34(b)(ii) (3 marks): Antibody levels were also measured two weeks after the first dose of vaccine. They were significantly lower than those measured after the second and third doses
  68. June 2017, Paper 3, Q5(c) (1 mark): Fig. 5.1, on the insert, is a photomicrograph showing tissues in the respiratory tract from one of the patients in the study. Name one structure, visible in Fig
  69. June 2017, AS Paper 1, Q20 (1 mark): Which of the options, A to D, is a primary defence mechanism against pathogens? A antibody molecules B the HPV vaccine C lysozyme, an enzyme found in saliva and
  70. June 2017, AS Paper 1, Q22(d)(i) (3 marks): Describe the inflammatory response. [3]
  71. June 2017, AS Paper 1, Q22(d)(ii) (1 mark): Using your knowledge, suggest how betalain pigments could interfere with the action of cytokines. [1]
  72. June 2016, AS Paper 1, Q3 (1 mark): A person can be immunised against some diseases by injecting them with antibodies extracted from another person or from an animal. Which of the options, A to D,
  73. June 2016, AS Paper 1, Q23(a)(i) (2 marks): Explain what is meant by the following terms. opsonin phagocytosis [2]
  74. June 2016, AS Paper 1, Q23(b) (3 marks): Antibodies, such as anti-p60, have a generalised structure. The generalised structure of an antibody is shown in Fig. 23. X Z Y Fig. 23 Name and describe the fu
  75. June 2016, AS Paper 1, Q23(c) (3 marks): Listeriosis can be fatal. Pre-screening food products for the presence of L. monocytogenes or p60 would be of great benefit to public health. The protein p60 ca
  76. June 2016, AS Paper 2, Q4(c) (3 marks): Mycobacterium tuberculosis is a bacterium that can cause TB. Screening for TB is done using a Mantoux test. Explain why a person who has immunity to TB develops

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