Question 21M.2.SL.TZ1.a.i
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.SL.TZ1.a.i |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Outline | Question number | a.i | Adapted from | N/A |
The image shows the wings of an insect, bird and bat.
[Source: [insect wing] Halvard Hatlen https://upload.wikimedia.org/wikipedia/commons/0/0f/Dip-trichoceridae-wing.png. [bird wing] University of Maryland, Department of Geology. [bat wing] University of Maryland, Department of Geology.]
Based on their structure, the insect and bat wings are analogous. Outline what is meant by an analogous trait.
[2]
a. analogous traits have a different evolutionary history/ancestry ✔
b. different structures are adaptations for flight ✔
c. selective pressure leads to a similar solution to the problem of flying ✔
Candidates found it hard to express themselves without contradiction.
In both parts the key to successful answers was in using the organisms given in the example. Contradictions were thus avoided.
