CAIE A-Level Biology AS 11.1.4 Memory Cells and Long Term Immunity Questions
Explain how memory cells produce long-term immunity using evidence from each question and mark scheme.
- Syllabus
- 2028–2030
- Course
- Biology 9700
- Level
- AS
Explain how memory cells produce long-term immunity using evidence from each question and mark scheme.
Influenza is an infectious disease caused by a virus.
It is possible to have influenza more than once.
Which statements explain why it is possible to have influenza more than once?
1 The viral antigens change as a result of mutations.
2 The immune system may be weak and make few B-memory cells.
3 Untreated HIV infection has resulted in a low T-helper cell count.
1, 2 and 3
1 and 2 only
1 and 3 only
2 and 3 only
A