| Date | May 2009 | Marks available | 1 | Reference code | 09M.1.HL.TZ2.12 |
| Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
| Command term | Question number | 12 | Adapted from | N/A |
Question
What do all human males inherit from their mother?
I. An X chromosome
II. A Y chromosome
III. Mitochondrial DNA
A. I only
B. I and II only
C. I and III only
D. I, II and III
Markscheme
C
Examiners report
Answers A and C were accepted as correct. As the origin of mitochondrial DNA is not in the syllabus, candidates could not be expected to know that mitochondrial DNA is only inherited from the mother.
