# AS Biology unit 2 Biodiversity questions and answers

Here exam questions for as biology unit2 OCR

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1. A group of students carried out some fieldwork to investigate the diversity of insects in
three habitats:
· a field of barley
· a field of wheat
· the vegetation under a hedge.
Their results are shown in the table below. The table also shows how they used their
data to calculate Simpson's Index of Diversity (D) for each habitat.
D = 1 ­ ((n/N)2)
where N = the total number of insects found, and n is the number of individuals of a
particular species.
number of individuals of each
species
in each habitat
barley wheat under
species field field hedge
a 32 4 0
b 78 0 1
c 0 126 2
d 0 5 12
e 0 0 8
f 0 0 9
g 0 25 3
h 0 10 3
i 0 0 2
j 0 0 5
k 86 56 0
l 0 0 7
species richness 3 6 10
total number of
insects (N) 196 226 52
Simpson's Index
of Diversity (D) 0.61 0.86
(a) State what is meant by the term species richness.
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[1]
(b) (i) Calculate the value for Simpson's Index of Diversity (D) for the barley field.
SWAKELEYS SCHOOL 1

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(ii) Using the data in the table, suggest why the value of Simpson's Index
of Diversity (D) for the vegetation under the hedge is so much higher
than that for the wheat field.
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(c) Describe how the students may have determined the numbers of individuals of
each species in each habitat.
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[Total 11 marks]

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AW;
more niches for insects in vegetation under hedge/ more species of
plants grow under hedge than in wheat field/ AW;
ref. use of, chemicals/ insecticides/herbicides, on wheat and not
on hedge vegetation;
AVP; e.g. ref. plants under hedge more likely to be wild/native
compared with wheat crop / AW max 3
(c) Any four from the following:

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Suggest why some conservationists might object to these studies.
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[Total 5 marks]
4. (i) ref to (bio)diversity values and need for conservation;
ref to endangered species and need for protection;
ref to laws concerning endangered species (that might affect decision);
ref to planning stipulation e.g. translocation of species;
AVP; e.g. example of type of local planning decision; max 3
(ii) damage to environment / ecosystem;
disturbance to animals in area;
habitats best left alone / left to nature/AW;

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Suggest two reasons why the black rhinoceros is endangered.
1 .............................................................................................................
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(b) State two ways in which the CITES agreement is helping to save endangered
species, such as the black rhinoceros.
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[Total 6 marks]

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Outline the potential benefits to agriculture of maintaining the biodiversity of wild
animals and plants.
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[Total 4 marks]
8. source of food;
source of plant varieties for cross breeding / selection;
to breed in disease resistance / pest resistance;
to breed in other named characteristic; e.g. higher protein content /
quicker growth
source of natural predators to pests;
AVP; max 4
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Braun-blanquet/ACFOR/
DAFOR/DOMIN)
11 ref to analysis of data/use of kite diagram;
12 AVP; ref to relevant statistical analysis, e.g. Spearmans Rank Correlation max 7
QWC - clear well-organised answer using specialist terms 1
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11. The Millennium Seed Bank Project (MSBP) is a global conservation programme
conceived, developed and managed by the Seed Conservation Department at the
Royal Botanic Gardens, Kew. The aims of the project are to collect and conserve 10%
of the world's seed-bearing plants by 2010.…read more

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In this question, one mark is available for the quality of spelling, punctuation and
grammar.
Zoos and botanic gardens, such as Kew Gardens, are involved in many conservation
projects throughout the world.
Outline the problems experienced by zoos and botanic gardens in managing such
projects and explain why it is important for such projects to be successful.…read more

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Management problems
1 capture of species/AW;
2 numbers of species caught ref to extinction;
3 ref to named example e.g. elephants;
4 maintenance of genetic variability/gene pool;
5 ref to funding;
6 ref to species ownership/AW;
7 problems of storage and maintenance;
8 ref to specific example of problem; e.g.…read more

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AW ;
man-made or natural changes in their environment /AW ;
A hunting and poaching
numbers, reduced to a critical level / so low that reproduction affected /
AW ; A only small numbers left max 2
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17. Hedgerows are important in farming as they act as sites of refuge for beneficial insects,
provide protection for the crop from adverse weather conditions and act as wildlife