| Date | May 2009 | Marks available | 1 | Reference code | 09M.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
What are the fundamental packaging units of eukaryotic chromosomes?
A. Nucleosomes
B. Centromeres
C. Histones
D. Nucleoids
Markscheme
A
Examiners report
This question seemed to be a bit complicated as many candidates confused the term packing units, considering they were the histones instead of the nucleosome. The discrimination index was quite good, showing that it did not prove that difficult to good candidates.
