| Date | November 2012 | Marks available | 2 | Reference code | 12N.3.SL.TZ0.11 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Outline | Question number | 11 | Adapted from | N/A |
Question
Using the mammalian pentadactyl limb as an example, outline the process of adaptive radiation.
Markscheme
limb bone pattern of mammals shows the same basic arrangement;
derived from common ancestor/homologous structures;
common ancestral pattern adapted to different environment conditions;
suitable example; (eg wing of bat adapted for flight and limbs of mole for digging)
Examiners report
Part (a) was poorly answered in general. Candidates could have obtained the 2 marks if they had known what adaptive radiation was without any reference to pentadactyl limbs. Although this very common example is not actually specified in the SL syllabus, this question was thus not compromised.
