DP Biology (last assessment 2024)
Question 20N.3.SL.TZ0.b
Date | November 2020 | Marks available | [Maximum mark: 2] | Reference code | 20N.3.SL.TZ0.b |
Level | SL | Paper | 3 | Time zone | TZ0 |
Command term | Outline | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
20N.3.SL.TZ0.b
Ecologists studied the distribution of five species of insectivorous wood warblers of the genus Dendorica living on different parts of coniferous trees in mature forests.
Outline the principle of competitive exclusion.
[2]
Markscheme
a. no two species can occupy the same niche;
b. competition between them would cause one species to drive the other out
OR
one of the two species would need to adapt and evolve accordingly;
Examiners report
When describing competitive exclusion many candidates simply described competition. Some mentioned habitat rather than niche.
