Question 19M.3.SL.TZ2.5c
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.SL.TZ2.5c |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Deduce | Question number | c | Adapted from | N/A |
Scientists investigated how relative brain mass varied in primate evolution. The graph shows the relative brain mass for species belonging to different primate groups against time of divergence from the common ancestor of modern humans in million years ago (Mya), 0 being the present era.
[Source: S Herculano-Houzel and J H Kaas, (2011), Brain, Behavior and Evolution, 77, pages 33–44.
© 2011 Karger Publishers, Basel, Switzerland]
Deduce, with a reason, whether the relative brain mass is a good indicator of brain development.
[1]
a. not a good indicator because it depends on body mass ✔
b. not a good indicator as less developed organisms show a larger relative brain mass ✔
Accept answers referring to specific organisms shown
In parts (b) and (c) few candidates referred to ‘relative’ brain mass thereby providing incorrect responses.
