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).