S4CH10: Biodiversity

• genetic diversity 


  the greater the number of alleles that all members of a species possess, the greater the genetic diversity of the species
• allele frequency


  the number of times an allele occurs within the gene pool of a population, relative to all others at the same locus
• gene pool

  all the different alleles of all the genes of all the individuals in a population at any one given time
• natural selection


  Darwin's theory: explains the mechanism of evolution. The process by which organisms better adapted to their environment survive and produce and pass on their advantageous alleles to their offspring, whilst those less well adapted fail to do so
• directional selection 


  favours one extreme of the range of characteristics and the other extreme is selected against - leads to a shift in the population curve
• stabilising selection


  favours the mean of the distribution because the extremes are at a selective disadvantage - frequency of mean phenotype increases
• polygenes


  group of genes that are responsible for controlling a characteristics
• normal distribution curve 


  a bell shaped curve produced when a certain distribution is plotted on a graph
• biodiversity 


  the range of variety of genes, species and habitats in a particular region. made up of genetic diversity, species diversity and ecosystem diversity
• binomial naming system


  Linnaeus' system to name species eg genus and species
• hierarchy


  groups within larger groups with no overlap between groups at each rank
• artificial classification


  process of classifying organisms based on differences useful at time
• phylogenetic classification 


  process of classifying organisms based upon evolutionary relationships between organisms and ancestors
• analogous characteristics 


  characteristics with the same function but not the same evolutionary origins
• homologous characteristics 


  characteristics with similar evolutionary origins regardless of their function in adult species
• taxon


  each group within a phylogenetic biological classification
• courtship behaviour


  a special behaviour that precedes fertilisation of eggs by a male to ensure successful reproduction
• classification 


  organisation of living things into groups
• taxonomy 


  the practice of biological classification
• domain 


  largest taxon - bacteria, archaea or eukaya
• kingdom 


  second largest taxon classification - eg eykarya domain splintos into animalia, plantae, fungi and protoctista
• community 


  the organisms of all species that live in the same area
• population


  a group of organisms of the same species occupying a particular space at a particular time that can be potentially inbred
• species diversity


  number of different species and number of individuals of each species within any one community
• ecosystem diversity 


  range of habitats within an area
• genetic diversity 


  variety of genes possessed by organisms that make up any one species
• species richness


  the number of different species represented in an ecological community. does not take into account the abundances of species or their relative abundance distributions
• index of biodiversity


  formula used to quantify the biodiversity of a habitat. takes into account the number of species present as well as the abundance of each species
• biomass


  the total mass of living material
• conservation


  management of the earths natural resources in such way that maximum use can be made of them in the future
• intercropping 


  the practice of growing two or more crops in close proximity usually to produce greater yield on a piece of land
• habitat 


  the place an organism lives
• random sampling 


  a way of sampling a population to eliminate bias
• sampling bias


  when a sample is collected in such way that some members of the intended population are more or less likely to be included that others. data collected therefore is inacurate as is bias and not representative
• sample size


  number of observations in a sample
• standard deviation 


  measure of how spread out about the mean your values are. the more spread the higher the standard deviation