| Date | May 2010 | Marks available | 1 | Reference code | 10M.1.SL.TZ2.13 |
| Level | Standard level | Paper | Paper 1 | Time zone | Time zone 2 |
| Command term | State | Question number | 13 | Adapted from | N/A |
Question
Which of the following is the cause of sickle-cell anemia?
A. Tryptophan is replaced by leucine.
B. Leucine is replaced by valine.
C. Glutamic acid is replaced by valine.
D. Lysine is replaced by glutamic acid.
Markscheme
C
Examiners report
This question turned out to be a good discriminator. Some teachers complained in the G2s that there was too much detail expected in this question. This exact statement is present however in the teacher notes of the guide.
