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Question 19M.3.HL.TZ1.17a.ii

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Date May 2019 Marks available [Maximum mark: 2] Reference code 19M.3.HL.TZ1.17a.ii
Level HL Paper 3 Time zone TZ1
Command term Suggest Question number a.ii Adapted from N/A
a.ii.
[Maximum mark: 2]
19M.3.HL.TZ1.17a.ii

In Wales, UK, the grey squirrel (Sciurus carolinensis) is an alien species and the red squirrel (Sciurus vulgaris) is endemic. The maps show the distribution of red and grey squirrels in 1945 and 2010.

[Source: © The Red Squirrel Survival Trust]

(a.ii)

Suggest two possible reasons for the change in distribution.

1.

2.

 

[2]

Markscheme

a. no predators ✔

b. ample food supply/habitats ✔

c. few competitors ✔

d. resistant to disease ✔

e. high reproductive rate ✔

f. no physical barrier to prevent spread of grey squirrels on mainland ✔

Examiners report

This was answered well by only a few students even though the mark scheme allowed for a wide range of answers.

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