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Date May 2019 Marks available 2 Reference code 19M.3.HL.TZ1.16
Level Higher level Paper Paper 3 Time zone Time zone 1
Command term Suggest Question number 16 Adapted from N/A

Question

The Vancouver Island marmot (Marmota vancouverensis) is a small rodent that is only found on Vancouver Island and is listed as critically endangered. Captive breeding and release programs for this species began in 1997 to attempt to restore population numbers on the island. The graph shows the causes of death of the marmots born in the wild and of those marmots released after being born and reared in captivity.

 

Distinguish between levels of predation in marmots born in the wild and those born in captivity.

[1]
a.i.

Suggest reasons for the differences in predation.

[2]
a.ii.

Distinguish between ex situ and in situ conservation of endangered species.

[1]
b.

Markscheme

predation was greater in those born in captivity ✔

a.i.

a. the marmots have experience with/recognize predators ✔

b. parents shield them from predators
OR
parents teach them about predators ✔

c. those born in the wild are favoured in natural selection

a.ii.

ex situ is in artificial environment, in situ is in natural environment ✔

Accept examples as long as it is clear one is natural and one artificial

b.

Examiners report

This question was generally well answered.

a.i.

Most candidates were able to score at least 1 mark here by commenting on either the greater experience with predators for marmots in the wild, or the role of learning. However, some examiners noted that students tended to use anthropomorphisms when discussing animals in this option. Also, it was surprising that very few students were able to achieve the marking point that those born in the wild were favoured by natural selection, as natural selection is one of the central ideas in biology.

a.ii.

Many candidates were able to achieve the mark distinguishing between in situ and ex situ. It should also be mentioned more students appear to be comfortable with questions that ask them to “compare,” “contrast” and “distinguish,” and this may be due to comments in previous subject reports. The most common mistakes had students reversing the two concepts and focusing on etymologies can help here.

b.

Syllabus sections

Option C: Ecology and conservation » Option C: Ecology and conservation (Core topics) » C.3 Impacts of humans on ecosystems
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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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