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Date November 2019 Marks available 2 Reference code 19N.3.SL.TZ0.13
Level Standard level Paper Paper 3 Time zone TZ0 / no time zone
Command term Compare and contrast Question number 13 Adapted from N/A

Question

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

[1]
a.

Compare and contrast fundamental and realized niche of a species.

[2]
b.

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 ✔

a.

a. both describe the habitat/role/relationship occupied by a species ✔

b. the fundamental niche is the potential role of a species in its ecosystem and realized niche is the actual role
OR
the fundamental niche depends on the adaptations of a species whereas the realized niche is limited by competition/predation
OR
realized niche is ‹usually› smaller than fundamental niche ✔

b.

Examiners report

[N/A]
a.
[N/A]
b.

Syllabus sections

Option C: Ecology and conservation » Option C: Ecology and conservation (Core topics) » C.1 Species and communities
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Option C: Ecology and conservation » Option C: Ecology and conservation (Core topics)
Option C: Ecology and conservation

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