| Date | May 2011 | Marks available | 1 | Reference code | 11M.1.HL.TZ1.23 |
| Level | Higher level | Paper | Paper 1 | Time zone | Time zone 1 |
| Command term | Question number | 23 | Adapted from | N/A |
Question
Which of the following statements about antibodies is correct?
A. Antibodies are polypeptides.
B. Antibodies are produced by the bone marrow.
C. Antibodies are pathogenic foreign substances.
D. Antibodies kill bacteria but not viruses.
Markscheme
A
Examiners report
There were several comments about the clarity of the wording of the answers to this question. It is agreed that A could have been worded more clearly as antibodies are proteins with a quaternary structure consisting of four polypeptide chains.
