Home · A-Level Biology 9700 · Immunity · Vaccination and types of immunity · Practice
AS · Practice questions · Vaccination and types of immunity

Memory cells make the difference.

Six original Cambridge-style questions on types of immunity, vaccines and vaccination programmes, including a short calculation.

Original questions All questions on this page are original work, written in the Cambridge AS & A Level style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

Who made the antibodies?

01
Analysis
[4 marks]

Describe the differences between active immunity and passive immunity.

  • Active: antibodies made by the person's own plasma cells after exposure to an antigen; passive: antibodies made by another organism and received. ✓
  • Active: memory cells are made; passive: no memory cells. ✓
  • Active: takes time to develop; passive: immediate. ✓
  • Active: long-lasting; passive: short-lived because the antibodies are broken down. ✓
02
Recall
[2 marks]

Give one example each of passive natural immunity and active artificial immunity.

  • Passive natural: antibodies crossing the placenta from mother to fetus, or in breast milk. ✓
  • Active artificial: vaccination. ✓
03
Explain
[4 marks]

Explain how a vaccine provides long-term immunity to a disease.

  • The vaccine contains antigens (for example from a dead or weakened pathogen) that cannot cause the disease. ✓
  • The antigens stimulate a primary response: T-helper and B cells with complementary receptors are selected and cloned. ✓
  • Plasma cells make antibodies and memory cells are formed. ✓
  • Memory cells remain for years and give a rapid secondary response if the real pathogen enters. ✓
04
Calculation
[2 marks]

In a model town of 225 people, 80% are vaccinated and immune. Calculate how many people are still susceptible to the disease.

  • Number vaccinated = 0.80 × 225 = 180. ✓
  • Susceptible = 225 − 180 = 45 people. ✓
05
Explain
[3 marks]

Explain how a mass vaccination programme can control the spread of an infectious disease, even though not everyone in the population is vaccinated.

  • Vaccinated people are immune, so they do not become infected and do not pass the pathogen on. ✓
  • When a high proportion is immune, an infected person is unlikely to contact a susceptible person, so transmission chains break. ✓
  • This herd immunity protects people who cannot be vaccinated, such as young babies. ✓
06
Explain
[3 marks]

Suggest why it has been difficult to develop vaccines against some diseases, such as influenza and malaria.

  • Influenza shows antigenic variation: its surface antigens change, so memory cells from earlier exposure or vaccines do not recognise new strains. ✓
  • The malaria parasite spends much of its life cycle inside body cells (liver and red blood cells), hidden from antibodies. ✓
  • Malaria parasites have many antigens that change between stages of the life cycle, so one vaccine does not target all stages. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.