4C diversity and classifications

• What are the two forms of classification?

  artifical and natural
• what is artificial classification?

  • division of organisms
  • based on obvious differences (colour, size etc.)
  • can be based on analogous characteristics (winged animals) 
• what is natural/phylogenetic classification?

  • division of organisms
  • based on evolutionary relationships
  • based on shared characteristics that have been taken from ancestors
  • hierarchy of groups formed
• What are the 8 groups in Linnaeus' system of Classification?

  domain, kingdom, phylum, class, order, family, genus, and species.
• what are the 3 domains?

  bacteria, archaea, eukarya
• describe the domain of bacteria?

  • 70S ribosomes
  • Unicellular
  • Murein Cell Walls
  • No membrane-bound organelles
  • Single loop of DNA, but no histones 
• describe the domain of archaea?

  • genes / proteins similar to eukaryotes
  • no murein in cell walls
  • more complex RNA polymerase
  • 70S ribosomes
  • CSM - fatty acids attached to glycerol by ether linkages 
• describe the domain of eukarya?

  • mainly multicellular
  • cells contain membrane-bound organelles
  • membranes contain fatty acids linked to glycerol via ester bonds
  • 80S ribosomes
  • cell walls chitin / cellulose
• 0.1 - Phylogenetic relationships can be shown using a …?

  Phylogenetic relationships can be shown using a phylogenetic tree
• What are the two techniques that have clarified evolutionary relationships between organisms?

  • immunological techniques
  • genome sequencing 
• How have we used gene sequencing to identify phylogenetic relationships?

  • Determined the entire base sequence for a particular species
  • Compare to other species
  • Assess similarity 
  • COMPARATIVE GENOMICS
• define species?

  • Group of similar organisms
  • Produce offspring
  • That are fertile
• what is ecosystem diversity?

  Range of different habitats within an area 
• define community?

  • Community all living organisms within a given area
• define population?

  • Population made up of members of single species, within a given area 
• define ecosystem?

  • Ecosystem all living organisms and the non living components
• how is monoculture involved in farming?

  • nvolves the rowing of a single crop in an area 
  • more water, mineral ions, carbon dioxide
  • pesticides can be used to reduce number of pests that damage crop plants
• disadvantages of monoculture?

  • pesticides could kill beneficial animals
  • costly - need to maintain the environment and monitor number of other organisms
  • if any pests do survive, then a monoculture enables them to spread rapidly
• what is taxonomy?

  • comparison of the frequency of observable characteristics
• what is the weakness of taxonomy?

  • limited by polygenic (coded for by more than one gene) features + environmental affects
• What is the difference between interspecific and intraspecific variation?

  interspecific variation = one species differing from another

   intraspecific variation = members of the same species differing
• what is genetic diversity?

  The number of different alleles of each gene
• what is phylogeny?

  The study of evolutionary history of groups of organisms This gives insight into relations of organisms
• what are taxa?

  Groups used to classify organismsThere are 8 taxa in totalA group is called a taxon
• how are taxa arranged?


  In hierarchyLargest groups are at the topSmallest groups are at the bottom
• What is the binomial system used for nomenclature of organisms?

  • A Latin name with two parts is given
  • The first part is the genus name, with a capital letter
  • The second part is the species name with a lowercase letter
  • Names are in italics, or underlined when hand written
• How has genome sequencing clarified evolutionary relationships?

  • The full DNA sequencing of organisms can be determined
  • Base sequences can be compared
  • Closely related species have high percentages of DNA base order similarity
• what is a habitat?

  A place where an organism lives
• what is species richness?

  The number of different species that are in a community
• List 5 agricultural practices that reduce biodiversity

  
  

  • Removing hedgerows
  • Clearing large woodlands
  • Use of pesticides
  • Use of herbicides
  • Monoculture
• How does removing hedgerows reduce biodiversity?

  • Smaller fields are made into one larger field
  • This destroys habitats
  • Biodiversity is reduced as habitats and food sources are removed
• How does the clearing of woodlands reduce biodiversity?

  • The number of trees, and the number of species of trees are both damaged
  • This means habitats are destroyed
  • The land is used for farming, but it means the species living there cannot use it for shelter and as a food source, particularly if pesticides are used
  • The species must migrate or die
• How does the use of pesticides reduce biodiversity?

  • These are chemicals used to kill the organisms that feed on crops - known as ‘pests'
  • The pests are killed, and biodiversity is reduced
  • Species that prey on the pests lose food sources, so their species numbers could also fall
• How does the use of herbicides reduce biodiversity?

  • These are chemicals used to kill the unwanted plants
  • The plants are killed, and biodiversity is reduced
  • Species that prey on the plants lose food sources, so their species numbers could also fall
• How does monoculture reduce biodiversity?

  • Growing only one type of plant, perhaps because it has high sale demand for food
  • Biodiversity is directly reduced by doing this, particularly is other plants that are natural to the area are killed and removed to make space
  • Also, fewer organisms can be supported
• What is the difference between species richness and an index of diversity?

  Species richness measures only the number of different species and does not measure the number of individuals
• Why is index diversity better than species richness 


  Index also measures abundance of each species
• What is species richness

  a measure of the number of different species in a community
• Give two other ways in which genetic diversity between species is measured.

  Comparing characteristics

  comparing amino acid sequences
• In binomial names what taxa is each part of the name

  Genus , species