Essential to maintaining a balanced ecosystem for all organisms.
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What are the three ways in which biodiversity can be measured?
Habitat, species and genetic.
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What is habitat biodiversity?
The number of different habitats found within an area. Each habitat can support a number of different species, in general the greater the habitat biodiversity, the greater the species biodiversity.
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What are the two components of species biodiversity?
Richness - the number of different species living in a particular area and evenness - a comparison of the numbers of individuals of each species living in a community.
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What is a community?
All the populations of living organisms in a particular habitat.
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What is genetic biodiversity?
The variety of genes that make up a species. Many of the genes for a species are the same but they have different alleles.
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What does greater genetic biodiversity mean?
Within a species - allows for better adaptation to a changing environment and more likely to be resistant to disease.
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What is sampling? What is it used for?
Taking measurements of a limited number of individual organisms present in a particular area. Can be used to estimate the number of organisms in an area without having to count them all. Also used to measure a particular characteristic.
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Describe random sampling
Selecting individuals by chance, equal likelihood of chance. Using random x and y coordinates to sample.
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What is non random sampling?
Where the sample is not chosen at random. Opportunistic - organisms that are available, stratified - random sample taken from a strata proportional to its size, systematic - line transect/belt transect.
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What is a weakness of sampling techniques?
Sampling bias - selection process may be bias. Chance - organisms selected may not be representative of the whole population.
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Give 5 ways to sample animals
Pooter - small insects, sweep nets - long grass, pitfall traps - small crawling invertebrates, tree beating - organisms in a tree/bush, kick sampling - organisms in a river.
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How are plants sampled?
Using a quadrat, can also be used on very slow animals like barnacles and mussels.
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What are the two types of quadrat?
Point quadrat and frame quadrat.
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What is the most valid sampling technique?
Random sampling as it has the least amount of bias
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What is a species richness?
A measure of the number of different species living in specific area
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What is a species evenness?
How close in numbers the population of each species in an environment is
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What are the three main ways of using a frame quadrat?
Density - easily visible. Frequency - grass/moss using small grids of the quadrat. Percentage cover - used for speed, useful when a species is abundant or difficult to count.
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Abiotic factors are non-living, true or false?
True
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What are some advantageous reasons for abiotic factors being measure quickly and accurately?
Rapid changes can be detected, human error in taking a reading is reduced, a high degree of precision can be achieved, data can be stored and tracked on a computer.
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How do you calculate biodiversity?
D= 1- the sum of (n/N)^2 where N=the total number of organisms of all species and n=the total number of organisms of a particular species.
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What does the value of Simpsons Index of Diversity always lie between?
0 and 1, where 0 represents no diversity and 1 represents infinite diversity.
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What are alleles?
Different versions of the same gene
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For genetic biodiversity to increase, what needs to happen to the alleles?
The variation in the genes needs to increase, more alleles.
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How can genetic biodiversity increase?
Mutation in DNA, interbreeding between different populations
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