[Maximum number: 4]

The European hedgehog, Erinaceus europaeus, is a small omnivorous mammal. Its body is covered in spines, which are usually brown. A rare variant, which lacks the brown pigment, has blonde (pale yellow) spines. This characteristic is coded for by a recessive allele.

Fig. 1.1 shows a European hedgehog with blonde spines.

Fig. 1.1

(a)

The hedgehogs on Alderney are an example of an invasive alien species.

Explain why it is sometimes important to control invasive alien species.

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[Maximum number: 3]

Fig. 5.1 shows a water vole, Arvicola amphibius. This species is native to Great Britain.

Fig. 5.1

The numbers of water voles are estimated to have fallen by 94 % in the last century.
This is thought to be due to habitat fragmentation and also to extensive predation by mink, Neovison vison, shown in Fig. 5.2. Mink originated in North America but were brought to Great Britain for fur farming. Some escaped or were released into the wild, where their numbers rapidly increased.

Fig. 5.2

(a)

(i)

Discuss the reasons why alien species should be controlled.

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