biodiversity

• courtship behaviour:

  • recognise members of own species (ensures offspring is fertile)
  • identify mate that is capable of breeding
  • form a pair bond
  • synchronise mating
  • become able to breed
• blue footed boobies

  • dance with brightly coloured blue feet
  • the brighter the blue, the more healthy it is and so the female would be more likely to pick that male
• phylogenetic classification:

  • based on evolutionary relationships
  • classifies species into groups using shared features derived from ancestors
  • groups contained within larger groups with no overlaps
• artificial classification:

  • classified using analogous characteristics
  • not based on evolution
• three domain system:

  • bacteria (absence of membrane-bound organelles, unicellular, smaller ribosomes, cell walls made of murein, circular dna no histones)
  • archaea (unicellular, genes+protein synthesis similar to eukaryotes, no murein in cells walls, membrane contain fatty acids attached to glycerol by ether linkages, more complex form of rna polymerase)
  • eukarya (membrane bound organelles, membranes have fatty acids attached to glycerol by ester linkages, not all have cell wall, if cell wall present it doesn’t contain murein, larger ribosomes)
• eukarya domain divided into four kingdoms:

  • protoctista
  • fungi
  • plantae
  • animalia
• domain

  kingdom

  phlyum

  class

  order

  family

  genus

  species
• species diversity -the number of different species and the number of individuals of each species within any one community
• genetic diversity - the variety of genes possessed by the individuals that make up a population of a species
• ecosystem diversity - the range of different habitats
• species richness - number of different species in a particular area in a community
• index of diversity

  the greater the value of d the greater the species diversity

  A) index of diversity

  B) N(N-1)

  C) sum of n(n-1)

  
• impact of agriculture:

  • little genetic diversity as farmers select species with particular qualities
  • intraspecfic competition within species as a large amount of same species is planted in the same area
  • species diversity is low in agricultural areas
• practices reducing species diversity:

  • use of pesticides and inorganic fertilisers
  • escape of effluent from silage stores and slurry tanks into water courses
  • lack of crop rotation and lack of intercropping or undersowing
• dna base sequencing to find genetic diversity