DP Biology (first assessment 2025)

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Question 19N.2.SL.TZ0.13a

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Date November 2019 Marks available [Maximum mark: 1] Reference code 19N.2.SL.TZ0.13a
Level SL Paper 2 Time zone TZ0
Command term Explain Question number a Adapted from N/A
a.
[Maximum mark: 1]
19N.2.SL.TZ0.13a
(a)

Explain why some biologists think protecting keystone species would help preserve biological diversity in an ecosystem.

[1]

Markscheme

a large effect on the ecosystem/community structure/environment«relative to abundance»
OR
influence the balance of other populations in the ecosystem
OR
other species in the habitat would also disappear
OR
many other species dependent on them for survival ✔

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