1.a) Answer in range 6.97-7 gains both marks. If your numerator was 6320 and/or denominator was 906, but you didn't get the answer 6.97-7, you would get one mark.
b) Any three of:

Decrease in variety of plants/fewer plant species
Fewer habitats/niches
Decrease in variety of food/fewer food sources
Machinery/pesticides/other aspect of clearing forest could kill insects

2. a) (i) (We should maintain biodiversity to) prevent extinction /loss of populations/reduction in populations /loss of habitats / save organisms for future generations
(ii) A suitable example of how some species may be important financially e.g. 1. medical / pharmaceutical uses; 2. commercial products / example given; 3. tourism; 4. agriculture; 5. saving local forest communities;
b) Any two of:
1. Fewer plant species / decrease in plant diversity; 2. Fewer habitats/nesting sites; 3. Fewer niches; 4. Fewer food sources/varieties; 5. Less protection from predators/ hunters/environment;
c) 1. Number of (individuals/birds of) each species; 2. Total number of birds;
d) Larger birds have a lower SA:vol ratio;
So less heat lost;
3. a) Removes bias
b) Answer in range 1.28-1.3
c) Diversity index would be lower (not a marking point in itself) as any two of:

Fewer/only three species
Mostly/dominated by one species/bird-cherry aphid
Fewer plant species

d) Data/evidence supports claim;
Only wheat field / only comparing with wood / one type of habitat /only insects considered;
e) Any two of:
1. Greater variety of plants; 2. Another habitat / more habitats / places to live / niches; 3. Another food source / more food types;

	Created by Stephen Cole over 10 years ago

A-Level Biology (Biodiversity (unit 2)) Note on Biodiversity notes and exam questions, created by Stephen Cole on 22/05/2014.