Explain why a person who has recovered from chickenpox is unlikely to become ill from the same disease again.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
After the first infection, the immune system creates memory lymphocytes that recognise the chickenpox virus.
These memory cells recognise the same antigen if the virus enters again.
They trigger a rapid production of antibodies.
The virus is destroyed before symptoms develop, so the person does not become ill again.
These memory cells recognise the same antigen if the virus enters again.
They trigger a rapid production of antibodies.
The virus is destroyed before symptoms develop, so the person does not become ill again.
Examiner tips
- Use the term ‘memory lymphocytes’ or ‘memory cells’. Explain the rapid antibody response. Show the link between memory cells and prevention of symptoms.
Common mistakes
- Using ‘immune cells’ instead of ‘memory lymphocytes’. Forgetting to mention the rapid antibody production. Saying the virus is ‘killed’ without linking it to the immune response.
Mark scheme (4 marks)
- Memory cells / memory lymphocytes are produced after the first infection
- Memory cells recognise the same antigen / pathogen if it enters the body again
- Antibodies are produced more quickly / a faster immune response occurs
- The pathogen is destroyed before symptoms develop / before the person becomes ill
Related
- All WJEC GCSE Biology (Wales) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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