DP Biology (first assessment 2025)

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Question 19M.2.SL.TZ2.a

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Date May 2019 Marks available [Maximum mark: 3] Reference code 19M.2.SL.TZ2.a
Level SL Paper 2 Time zone TZ2
Command term Explain Question number a Adapted from N/A
a.
[Maximum mark: 3]
19M.2.SL.TZ2.a

Explain the factors that can contribute to the exponential growth phase in a sigmoid population curve.

[3]

Markscheme

a. ideal environment/unlimited resources/below carrying capacity ✔

b. little disease/few predators ✔

c. high natality/birth rate AND immigration ✔ Both needed.

d. natality and immigration greater than mortality and emigration ✔

Examiners report

The vast majority of candidates could provide part of an explanation; most mentioned resources, but for many the effect of natality, mortality, immigration and emigration (both not well distinguished for some) was obscure.

Syllabus sections