4.2.1 Biodiversity Flashcards
What is a population?
A group of organisms from the same species, living in the same area
What is a community?
All of the different populations / species living in the same area.
What is an ecosystem?
The interaction between the community and the non-living parts of the environment
What is a habitat?
The place where an organism lives.
What are the three different levels of biodiversity?
- Habitat
- Species
- Genetic
(In any order)
What is species diversity?
The number of different species in an area.
What is habitat diversity?
The number of different habitats in an area.
What is genetic diversity?
The diversity of genes within a species.
What is species richness?
The number of different species in an area.
What is species evenness?
A measure of the distribution of abundance of species in a community.
Why is random sampling often used to sample an area?
Reduces bias
Describe a method of random sampling to sample the number of daisies on the school field.
- Divide sampling area into a sampling grid
- Use a random number generator to generate coordinates
- Place the quadrat at the random coordinate
- Count the number of daisies in the quadrat
- Repeat at least 10 times
- Calculate the mean number of daisies in a quadrat
- Multiply the mean by the area of the sampling grid
What is systematic sampling?
When samples are taken along fixed intervals, e.g. a transect
Give four examples of opportunistic sampling.
- Sweep nets
- Pooters
- Kick sampling
- Pit fall traps
When is stratified sampling used?
When their are multiple habitats within one sampling area
In the equation for Simpson’s diversity index, what does ‘N’ stand for?
The total number of ALL organisms
In the equation for Simpson’s diversity index, what does ‘n’ stand for?
The total number of organisms belonging to one species
The value for Simpson’s diversity index should always fall between which two numbers?
0 and 1
If Simpson’s diversity index is close to 1, what does this tell you?
- More diverse habitat
- More able to cope with change
- More stable
If Simpson’s diversity index is close to 0, what does this tell you?
- Less diverse habitat
- More easily damaged by change
- Less stable
What is a locus?
The physical location of a gene on a chromosome
How can a measure of genetic diversity in a population be achieved?
By calculating the proportion of polymorphic gene loci
What is a polymorphic locus?
A locus that has multiple alleles (versions of a gene)
How do you calculate the proportion of polymorphic gene loci?
Number of polymorphic gene loci / Total number of loci
