investigating diversity

• what are four ways genetic diversity within or between species can be made

  -frequency of measurable/observable characteristics

  -base sequence of DNA

  -base sequence of mRNA

  -the amino acid sequence of the proteins encoded by DNA and mRNA
• what is the method of measuring observable characteristics based on


  each observable characteristic is determined by a gene
• what are two limitations when measuring genetic diversity by characteristics


  - many are polygenic so it is difficult to distinguish the certain gene

  - characteristics can be modified by the environment so differences may be due to the organisms environment not its alleles
• what does sampling involve 


  taking measurements of individuals, selected from the population of organisms which is being investigated
• what are two reasons measurements may not be representative

  - sampling bias

  - chance
• how can we reduce sampling bias

  carrying out random sampling
• how can we carry out random sampling

  1. divide the study area into a grid of numbered lines
  2. using random generated numbers obtain a series of coordinates
  3. take samples at the intersection of each pair of coordinates
• what are two ways we can remove chance

  - using a larger sampling size

  - analysing data collected with statistical tests