| Date | May 2015 | Marks available | 1 | Reference code | 15M.1.HL.TZ2.36 |
| Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
| Command term | Outline | Question number | 36 | Adapted from | N/A |
Question
The graph is about defence against infectious disease.
What is likely to be indicated by the letter X?
A. The increase in lymphocytes following HIV infection
B. The peak of the infection
C. The secondary response to a vaccine
D. The first appearance of AIDS symptoms
Markscheme
C
Examiners report
This question was not too clear because the axis in the graph do not say this is showing a vaccination process, therefore confusing candidates.
