Question 23M.1.HL.TZ1.10
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.HL.TZ1.10 |
| Level | HL | Paper | 1 | Time zone | TZ1 |
| Command term | Question number | 10 | Adapted from | N/A |
Scientists sequenced the genes in each chromosome of chimpanzees (Pan troglodytes) and humans (Homo sapiens). The graph shows the mean divergence between the genes of these species by chromosome.
[Source: Material from: Mikkelsen, T.S. et al, Initial sequence of the chimpanzee genome and
comparison with the human genome, 2005 Nature, reproduced with permission of SNCSC.]
What can be deduced from this data?
A. Autosomes are more similar than Y chromosomes.
B. There is the same number of chromosomes in humans and chimpanzees.
C. Humans are more closely related to chimpanzees than to other species.
D. Smaller chromosomes are more similar than larger chromosomes.
[1]
A
About 40% of candidates answered correctly. The discrimination index was high. There were comments from teachers that candidates could not be expected to know that the chromosome number in humans and chimpanzees is different, but this knowledge is part of an Application in 3.2 of the Core.