calculating genetic biodiversity

• why is it important to maintain genetic biodiversity?

  • individuals can suffer from a range of problems which result from inbreeding
  • variation needed for disease resistance- prevent extinction of a population
• what is gene flow?

  when an individual travels from one population and breeds with a member from another, transferring alleles between the two populations
• what are genetic bottlenecks?

  where few individuals within a population survive an event, reducing the gene pool. Only alleles available to be passed onto offspring are those of the survivors
• what is the founder effect?

  a small number of individuals create a new colony, geographically isolated from another. The gene pool for this is small
• what is genetic drift?

  Random changes in allele frequencies in a population due to random nature of alleles being passed on from parent to offspring. More obvious in populations with low genetic biodiversity
• list all the factors that affect genetic biodiversity

  • mutation
  • genetic bottlenecks
  • founder effect
  • natural selection
  • selective breeding
  • genetic drift
  • captive breeding programmes eg zoos
• how do scientists quantify genetic biodiversity?

  by measuring polymorphism
• what are polymorphic genes?

  have more than one allele- eg blood type
• what is the term used to describe a single allele existing for a particular gene?

  • monomorphism
  • ensures basic structures of individuals within species remains constant
• how can the proportion of polymorphic genes be measured?

  proportion of polymorphic gene loci = number of polymorphic gene loci / total number of loci

  loci/locus= position of a gene on a chromosome
• what can be concluded from measuring polymorphic gene loci?

  the greater the polymorphic gene loci, the greater the genetic biodiversity within the population