biodiversity. Flashcards
(12 cards)
Define the term species.
A group of similar organisms that can reproduce to produce fertile offspring.
Define the term habitat.
The area inhabited by a species, including the biotic and abiotic factors.
Define the term biodiversity.
The variety of living organisms in an area.
State the three levels of biodiversity and for each one describe what it means.
Habitat – the number of different habitats in an area.
Species – the number of different species in an area.
Genetic – the variation of alleles within a species.
Describe the difference between species richness and evenness.
Species richness = the number of different species in an area
Evenness = a measure of the relative abundance of each species in an area.
Describe how you would carry out random sampling to estimate the population of plant species in a habitat
Set out a grid with coordinates in the habitat.
Use a random number generator to obtain random coordinates (minimum of 20).
Place the quadrat at the first coordinate.
Use a key to identify the species present.
Count how many of each plant species there are (the abundance).
Repeat for each quadrat.
Calculate the area of the quadrat.
Calculate the mean number of each plant species per quadrat.
Measure the area of the whole habitat.
Calculate how many times bigger the area is that the quadrat.
Multiply that by the mean number of each plant per quadrat.
Describe how you would investigate the animal diversity in two areas of grassland.
Use a sweep net at the first site.
Sweep for 1 minute.
Empty the net into a white tray.
Use a key to identify all the species present.
Count how many of each species there are (the abundance).
Repeat twice more at the same site.
Calculate a total number for each species.
Move to the second site and repeat the sampling.
Must be the same time sweeping and number of repeats.
Calculate the Simpson’s Index of Diversity for each site.
State the values that the Simpson’s Index of Diversity will always be between.
0-1
Describe the significance of a high and low value of Simpson’s Index of Diversity.
The closer to 1, the more biodiverse the habitat is.
Therefore the habitat is more stable.
The closer to 0, the less biodiverse an area is.
Therefore the habitat is less stable.
Describe why Simpson’s Index of Diversity is a better measure of biodiversity than species richness or evenness.
Simpson’s Index of Diversity takes into species richness and evenness.
State the three types of non-random sampling. For each one describe what it means.
Systematic – Samples are taken at fixed intervals, often along a line. For example a transect.
Opportunistic – Samples are chosen by the investigator. This can produce biased data.
Stratified – Different areas in a habitat are identified and sampled separately, in proportion to their part of the habitat as a whole.
Explain how genetic biodiversity may be assessed.
Calculate the proportion of polymorphic gene loci
Proportion of polymorphic gene loci = number of polymorphic gene loci / total number of loci
The higher the proportion of polymorphic gene loci the higher the genetic biodiversity.
