Question 19M.1A.HL.TZ2.26
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.HL.TZ2.26 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Deduce | Question number | 26 | Adapted from | N/A |
The cladogram shows some major orders of placental mammals and is based on biochemical evidence.
[Source: © International Baccalaureate Organization 2019]
Which conclusion can be drawn from evidence in the cladogram?
A. Primates and Sirenia have not evolved from a common ancestor.
B. Primates and Cetacea do not form part of any clade.
C. Cetacea are less closely related to Sirenia than to Primates.
D. Xenarthra have not been changed by evolution for longer than other clades.
[1]
C
Some candidates failed to realize that Xenarthra are more closely related to Primates than to Sirenia as they evolved more recently from the former. Xenarthra evolved from Boreoeutheria into different species and after that did not change by evolution, while all other species did change.
