Biodiversity and classification

• What is classification?


  The process of naming and organising organisms into groups based on their characteristics and evolutionary history
• Can the classification of an organism change?


  Yes, if new information becomes available
• What are the seven groups in the Hierarchy of Taxons from largest to smallest?


  Kingdom, phylum, class, order, family, genus, species
• What is the Five Kingdom Classification System?


  Animalia, fungi, plantae, prokaryotae and protoctista
• What is the Three Domain Classification System?


  A method of classification in which organisms are categorised into three groups; archaea, bacteria and eukarya
• How was the Three Domain System developed?


  By analysing molecular differences between organisms to determine their evolutionary relationships

  Evidence showed that the kingdom 'prokaryotae' could be divided into two groups. All other organisms are eukaryotes
• What do organisms in Same Domain have in common?


  Organisms in the same domain share a distinctive pattern of rRNA
• What is Bacteria?


  One of the three domains

  Consists of 'true' bacteria

  Also known as eubacteria
• What is Archaea?


  One of the three domains

  Made up of primitive bacteria existing in extreme environments, e.g. extremophile prokaryotes

  Also known as archaebacteria
• What is Eukarya?


  One of the three domains

  Consists of all eukaryotic organisms
• What are the Features of Kingdom Prokaryotae?


  Unicellular prokaryotes

  Lack a true nucleus and membrane-bound organelles

  Rigid cell wall
• What are the Features of Kingdom Plantae?


  Multicellular eukaryotes

  Photoautotrophs

  Cellulose cell walls
• What are the Features of Kingdom Animalia?


  Multicellular eukaryotes

  No cell wall

  Heterotrophic

  Nervous coordination
• What are the Features of Kingdom Fungi?


  Eukaryotes

  Heterotrophic

  Chitin cell walls

  Grow by producing branching filaments, hyphae

  Asexual reproduction via spores
• What are the Features of Kingdom Protoctista?


  Mainly unicellular eukaryotes

  No differentiation into tissues
• How are different types of Evidence used in Classification?


  Observations (e.g. fossils) - organisms grouped based on similar physical characteristics

  Biochemical methods (e.g. DNA genetic fingerprinting)
• What is DNA Profiling?


  Method of determining the characteristics of an individual's DNA

  The percentage of DNA or proteins shared between species is used to estimate relatedness
• What is the Advantage of Biochemical Methods of classification?


  Biochemical methods reduce mistakes made from observing physical features alone due to morphological convergence
• Compare Homologous and Analogous features?


  Homologous features have evolved from the same structure for different functions. They indicate a common ancestor

  Analogous features are structures that have evolved independently for the same function
• What is an example of a homologous feature?


  Pentadactyl limb (found in mammals, birds and reptiles)
• What is an example of an analogous feature?


  The wings of birds and insects
• What does species mean?


  A group of organisms that can interbreed to produce fertile offspring
• What are the two components of a binomial name?


  Generic name - the Genus to which the organism belongs

  Specific name - the species the organism belongs to
• What is the advantage of the binomial naming system?


  It is universal: an organism's binomial name is the same everywhere in the world
• What is biodiversity?


  The number and variety of living organisms in a given region

  It is affected by environmental, genetic and human factors
• What mechanism has generated biodiversity?


  Natural selection
• What must ecologists consider when measuring the biodiversity of a habitat?


  Species richness

  Species evenness
• What is species richness?


  The number of different species found within an area
• What is species evenness?


  The number of individuals of each species living together in a community
• How can the biodiversity in a habitat be assessed?


  Using Simpson's Diversity Index
• What is Simpson's Diversity Index?


  A measurement of diversity that considers both species richness and evenness

  A value between 0 and 1 is found

  The greater the value, the greater the biodiversity
• How can we calculate genetic diversity within a species?


  Proportion of polymorphic gene loci = number of polymorphic gene loci/total number of loci
• What is polymorphism?


  The presence of different phenotypes among members of a single species
• How can biodiversity be assessed at the molecular level?


  Using DNA fingerprinting and sequencing
• What is DNA sequencing?


  Determining the entire DNA nucleotide base sequence of an organism
• How is DNA sequencing to used to measure biodiversity?


  Comparisons between members of the same species can identify variation in base sequences and hence estimate genetic diversity.
• What is adaptation?


  A feature of an organism that increases its chance of survival in its environment
• What are the types of adaptation?


  Anatomical - changes to physical features

  Physiological - changes to bodily processes

  Behavioural - changes to actions