3.4 Topic 4 - 3.4.6 Biodiversity within a community Flashcards
give a definition for biodiversity
the number and variety of living organisms in a particular area.
what 3 components does biodiversity have?
species diversity, genetic diversity and ecosystem diversity.
what does species diversity refer to?
refers to the number of different species and the number of individuals of each species within any one community.
what does genetic diversity refer to?
refers to the variety of genes possessed by the individuals that make up a population of a species.
what does ecosystem diversity refer to?
refers to the range of different habitats, from a small local habitat to the whole of the earth.
what is the measure of species diversity called?
species richness.
what does an index of diversity describe?
the relationship between the number of species in a community and the number of individuals in each species.
give the index of diversity formula
d = N (N- 1) / £n(n - 1)
what does the N in the index of diversity formula mean?
total number of organisms of all species.
what does the n in the index of diversity formula mean?
total number of organisms of each species.
what does the £ in the index of diversity formula mean?
the sum of.
what does a high value of the index of diversity mean?
the species diversity is high.
what techniques reduce biodiversity?
farming and agriculture.
what do natural ecosystems become after developing over time?
complex communities with many individuals of a large number of different species – these communities have a high index of diversity.
what happens to the number of species when farmers select species for particular qualities that make them more productive?
the number of species, and the genetic variety of allele they possess is reduced to the few which exhibit the desired features.