| Date | November 2017 | Marks available | 1 | Reference code | 17N.1.SL.TZ0.23 |
| Level | Standard level | Paper | Paper 1 | Time zone | TZ0 |
| Command term | Deduce | Question number | 23 | Adapted from | N/A |
Question
The table shows the number of differences between humans and other selected organisms for the protein cytochrome c oxidase. This protein, consisting of 104 amino acids, is located in the mitochondria and functions as an enzyme during cell respiration.
If the data were used to draw a cladogram, which chordates would be furthest apart from humans?
A. Chimpanzee because it has zero differences
B. Fruit fly because it has the most differences
C. Tuna fish because it is the chordate with the most differences
D. Horse because it is in the same class
Markscheme
C
Examiners report
[N/A]
