Assessing biodiversity

• What does an examination of genes and alleles assess?

  Biodiversity at the gene level
• What does the approach to assessing biodiversity focus on?

  All alleles in the gene pool
• What is a gene's position on a chromosome called?

  Locus
• What indicates that a locus shows polymorphism?

  It has more alleles than expected by mutation
• How does the number of alleles affect the polymorphism of a locus?

  More alleles indicate higher polymorphism
• What does Gene T control in plants?

  • Controls height
  • Has two different alleles
• What does Gene S control in plants?

  • Controls pollen germination on stigma
  • In one species of poppy, has 31 different alleles
• Why does Gene S have greater biodiversity than Gene T?

  More phenotypes are possible with Gene S
• What indicates low biodiversity for a gene?

  90% of alleles are the same recessive allele
• What happens to biodiversity if 50% of alleles are recessive?

  Biodiversity of the gene would be higher
• How many alleles does the ABO gene have?

  Three alleles
• What is the frequency of I^O among the indigenous population of Central America?

  Almost 100%
• How does the biodiversity of the indigenous people of Guinea compare to that of Central America?

  Guinea has higher biodiversity
• What are the approximate percentages of alleles in the gene pool for Central America?

  • I^A: 81%
  • I^B: 2%
  • I^O: 98%
  • Relative biodiversity: low
• What does DNA fingerprinting reveal about organisms?

  Closely related organisms have similar DNA
• What are the approximate percentages of alleles in the gene pool for Guinea?

  • I^A: 25%
  • I^B: 10%
  • I^O: 61%
  • Relative biodiversity: high
• What is the function of non-coding DNA?

  Undergoes mutation
• What are SNPs?

  Single nucleotide polymorphisms
• What are variable regions in DNA?

  Unique lengths of non-coding DNA
• What is the length of variable regions typically?

  About 20–40 base pairs long
• What are the stages of natural selection?

  1. Variation: Differences in DNA
  2. Competition: Different appearances and functions
  3. Competitive advantage: Some out-compete others
  4. Survival of the fittest: Better survival chances
  5. Reproduction: Passing on genes
  6. Pass advantageous alleles: Offspring inherit advantageous traits
• What is natural selection?

  Process where best adapted survive
• How does natural selection increase the frequency of characteristics?

  Gradually increases frequency of advantageous traits