Chapter 10

• Species


  A group of organisms that can interbreed to produce fertile offspring
• Advantages of courtship behaviour


  • Individuals can recognise sexually mature members of their own species of the opposite sex
  • Individuals can synchronise mating
  • Individuals can form a pair bond
  • Individuals can successfully breed
• Classification


  The process of arranging organisms into groups
• Classification hierarchy from largest to smallest


  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Binomial naming system


  System used to give species a universal name
• Binomial name


  • Generic name (genus)
  • Specific name (species)
• How binomial names are handwritten


  • First letter of generic name capitalised, rest lowercase
  • Whole name underlined
• Phylogenetic classification


  The process of arranging organisms into groups based on their evolutionary origins and relationships
• Clarifying evolutionary relationships between organisms


  1. Analyse molecular differences

  2. Use advances in immunology/genome sequencing
• Hierarchical classification


  • Groups within groups
  • No overlap between groups
• Biodiversity


  The variety of living organisms
• Biodiversity


  • Can be measured in terms of species diversity (number of species in a community), ecosystem diversity (range of different habitats) and genetic diversity
• Community


  All the different species that live in one area and interact with each other
• Calculating index of diversity (d)


  1. N= total number of organisms of all species

  2. n= total number of organisms of each species

  3. Σ = sum of
• Agriculture (farming)


  Decreases species richness
• Agriculture (farming)


  Decreases genetic diversity
• Increasing biodiversity in areas of agriculture


  1. Use hedgerows instead of fences

  2. Grow different crops in the same area, or rotate crops around after a season

  3. Limit use of pesticides and herbicides
• Ways to compare genetic diversity between organisms


  • Frequency of observable characteristics
  • Base sequence of DNA
  • Base sequence of mRNA
  • Amino acid sequence
• Gene technology


  Sampling DNA or mRNA in order to read and compare the base sequence of organisms. Alternatively the amino acid sequence can be studied as this will also provide information on the organism's mRNA and DNA sequences.
• Scientists prefer to use gene technology instead of observation because simply inferring DNA differences by observing an organism's characteristics is not reliable; the characteristics could be coded for by more than one gene, or could be influenced by the environment.
• Interspecific variation


  Differences between individuals of different species
• Intraspecific variation


  Differences between individuals of the same species
• Sampling


  Selecting a group of individuals to measure that will represent the whole target population
• Achieving a random sample


  Create a grid for your sample area, and then randomly generate coordinates where a quadrat or transect can be placed. Repeat until required sample size is reached.