Biodiversity

What is biodiversity?

The variety of life in a given area.

What is species richness?

The number of different species present within a community.

What is the index of diversity?

The relationship between the number of different species within a community and the number of individuals of each species.

True or false? Biodiversity can only be applied to local habitats.

False. BIODIVERSITY CAN BE APPLIED TO ALL HABITATS, NO MATTER THEIR SIZE.

True or false? A low biodiversity is not always a concern.

True.

When is a lower biodiversity a concern?

When the biodiversity of an area was previously high but has started to decrease.

Give the formula for the index of diversity.

True or false? The lower the index of diversity, the greater the biodiversity.

False. THE GREATER THE INDEX OF DIVERSITY, THE GREATER THE BIODIVERSITY.

True or false? Modern farming techniques often maximise food production but reduce biodiversity.

True.

Give and explain four reasons why farming leads to decreased biodiversity.

• Habitats are removed.

• Monocultures are promoted (so species richness and food variety reduced).

• Use of pesticides and herbicides (insects and plants that are food sources for other organisms are killed).

• Overuse of fertilisers (can lead to eutrophication which can lead to death of aquatic ecosystems).

What is genetic diversity?

The variety of alleles within or between species.

Give four ways in which you can measure the genetic diversity of a population.

• Measure the frequency of observable characteristics.

• Get DNA base sequence.

• Get mRNA base sequence.

• Get amino acid sequence of proteins.

Why is measuring the frequency of observable characteristics not as reliable as other ways to measure genetic diversity?

Characteristics are likely to be influenced by environmental factors as well as just genes.

Why is it less reliable to get the amino acid sequence of a protein when investigating genetic diversity?

The genetic code is degenerate so two individuals could have the same amino acid sequence but actually different DNA base sequences coding for it, meaning they’d be mistaken as being genetically closer than they actually are.

Why is getting DNA sequence/ mRNA sequence the best way to investigate genetic diversity?

It gives an objective measure of genetic diversity as opposed to just looking at (subjective) observable traits and the degenerate nature of the genetic code doesn’t change anything.

Why should data be collected via random sampling?

To avoid bias.

How can you ensure your data is representative of a population?

Take large samples in investigations

What is standard deviation?

A value that represents the spread of values around the mean.

What is a population?

All the organisms of the same species living in a particular space at a particular time that can potentially interbreed.