Module 4, Section 2: Biodiversity.

Systematic sampling? What’s a negative of this type of sampling?

Samples taken at fixed intervals, along a point, like a line. Systematic sampling is often prone to bias however.

Opportunistic sampling?

Samples are chosen by the researcher. Also massively prone to bias, due to an uneven spread of testing.

Stratified sampling?

When different parts of the population are assessed in proportion to their part of the habitat. So, if there’s an abundance of dandelions, they will be sampled according to this.

What are some techniques of assessing biodiversity using samples?

1. Pitfall traps, for small animals like beetles and small reptiles.

2. A pooter, for small land dwelling insects.

3. Net: For organisms living in long grass, tip into collecting tray.

What is species richness and evenness?

Richness is the amount of species present in a population, while evenness is to do with the relative abundance of these species.

What does a diversity index of close to zero mean? And what does one close to 1 mean?

zero = very low biodiversity

closer to one = High biodiversity.

What effect does environmental changes have on a habitat with low index values compared to one with high index values?

Environmental changes have a higher impact on a habitat with low index values.

Whats a polymorphic gene locus?

Area on chromosome that can have more than one type of allele.

Why is genetic diversity crucial?

Allows the population to better survive changing environmental factors, both abiotic and biotic.

Why is monoculture bad

Reduces biodiversity by eliminating local plants and animals

What are ecological reasons to maintain biodiversity?

Keeping keystone species alive and keeping food webs regulated.