Question 19N.2.SL.TZ0.c
| Date | November 2019 | Marks available | [Maximum mark: 1] | Reference code | 19N.2.SL.TZ0.c |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | c | Adapted from | N/A |
Explain why some biologists think protecting keystone species would help preserve biological diversity in an ecosystem.
[1]
a. «research demonstrates that keystone species» have a «disproportionately» large effect on their environment relative to abundance
OR
«keystone species» maintain a balance in the «stable» numbers of each species within a community
OR
«keystone species» have a large impact in preserving and stabilizing the biodiversity by preventing overpopulation/monopoly/out competition ✔
b. a keystone species’ disappearance would start a domino effect/other species in the habitat would also disappear
OR
their loss leads to an imbalance in the food web
OR
their loss leads to a decrease in biodiversity ✔
Do not accept protecting keystone species prevents disappearance of other species since it repeats the question.
