3.7 Mass Extinction and Biodiversity

Question 1

State the three components of biodiversity

Answer 1

1. Genetic diversity
2. Species diversity
3. Ecosystem diversity

Question 2

Define genetic diversity

Answer 2

the number and frequency of all the alleles within a population

Question 3

Explain why genetic diversity is important

Answer 3

Lack of genetic diversity may limit its ability to adapt to changing conditions

This could happen if some populations died off, e.g. over hunting

Question 4

State the two components of species diversity

Answer 4

• Species richness
• Relative abundance

Question 5

Define ‘species richness’

Answer 5

number of different species in an ecosystem

Question 6

Define ‘relative abundance’

Answer 6

proportion of each species in the ecosystem

Question 7

How does the presence of a dominant species affect species diversity in a community?

Answer 7

A community with a dominant species has a lower species diversity

Question 8

Compare the species diversity of two communities with the same species richness, one with a dominant species and one without.

Answer 8

The community without a particularly dominant species will have higher species diversity

Question 9

Define ‘ecosystem diversity’

Answer 9

the number of distinct ecosystems within a defined area