4.2.1: Biodiversity

Question 1

What is biodiversity?

Answer 1

The variety of living organisms. It can be measured in terms of species diversity (number of species in a community), habitat diversity (range of different habitats) and genetic diversity (variety of alleles within a species).

Question 2

Differentiate between species richness and species

evenness.

Answer 2

● Species richness= the number of species in an area.

● Species evenness= whether species have similar numbers.

Question 3

Discuss different types of sampling.

Answer 3

● Random= no particular system, however aim is still to be representative.
● Opportunistic= those that are encountered first are chosen.
● Stratified= population divided into smaller groups based on a characteristic, then sampled.
● Systematic= follows a particular pattern.

Question 4

Why is sampling important?

Answer 4

We cannot study the whole population as it is impractical. Using a representative sample instead allows us to investigate the population easily.

Question 5

Describe how Simpson’s Index of Diversity is used.

Answer 5

● A measurement of the total number of organisms compared to the total number of organisms of each species.
● A high index of diversity means several different species are equally abundant, whereas a low index
means one or two species dominate over others.

Question 6

How can we assess genetic diversity?

Answer 6

Proportion of polymorphic = gene loci number of polymorphic gene loci/total number of loci

Question 7

Give factors that affect biodiversity.

Answer 7

● Population growth
● Deforestation for agriculture
● Climate change affecting habitats

Question 8

Give reasons to maintain biodiversity.

Answer 8

● Ecological= protecting species, maintaining resources.
● Economic= reducing soil depletion.
● Aesthetic= protecting landscapes.

Question 9

Define conservation.

Answer 9

The protection and management of species and habitats, in order to maintain biodiversity. Can be in-situ (in an
organism’s habitat) or ex-situ (outside an organism’s habitat).

Question 10

Give examples of in-situ conservation.

Answer 10

● Marine conservation zones

● Wildlife reserves

Question 11

Give examples of ex-situ conservation.

Answer 11

● Seed banks
● Botanic gardens
● Zoos

Question 12

Give some agreements made with the aim of protecting species and habitats.

Answer 12

● Convention on International Trade in Endangered Species (CITES).
● Rio Convention on Biological Diversity (CBD).
● Countryside Stewardship Scheme (CSS).