Threats to Biological Diversity

Question 1

Habitat destruction (example)

Answer 1

Coral reefs
– Destructive fishing 
– cyanide fishing 
– segmentation 
– eutrophication 
– coral bleaching

Question 2

Fragmentation example

Answer 2

E.g. Madagascar
More area exposed to edge effects
Population divided and less gene flow

Question 3

Degradation

Answer 3

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Question 4

Global Climate Change

Answer 4

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Question 5

Overexploitation examples

Answer 5

Bushmeat
Cod stocks - fishing down the food web
Tropical timber – big trees older
Whaling

Question 6

How Invasive species are introduced into new areas? (4)

Answer 6

1. Colonisation by people – E.g. Rabbits in Australia
2. Horticulture, agriculture and forestry
3. Accidental transportation - e.g. ship ballast
4. Biological control – e.g. cane toads

Question 7

Disease - three examples

Answer 7

Western lowland gorillas - Central Africa
African wild dogs - Serengeti-Mara
Monks seals West Africa

Question 8

How can human activities affect disease incidence in wild animals

Answer 8

Increased contact with possible diseases

Question 9

How can contact with possible diseases be increased by human activities:

Answer 9

Alter host density
Alter parasite density
New transmission routes
By introducing reservoir hosts