3.4.7 Investigating diversity

    avatar
    Created by
    E

    Cards (9)

    • The link between DNA and the tertiary structure:
      A) triple
      B) DNA
      C) gene
      D) exon
      E) transcription
      F) codon
      G) mRNA
      H) translation
      I) amino
      J) primary
      K) R-group
      L) bonds
      M) ionic
      N) hydrogen
      O) disulphide
      P) tertiary
    • Different ways to classify organisms:
      • Comparison of observable features- not useful due to polygenetic characteristics.
      • Comparison of DNA base sequences- closely related organisms can be identified and mutations can be seen between distantly-related organisms.
      • Comparison of the base sequence of mRNA.
      • Comparison of the amino acid sequence in proteins.
    • DNA sequence can be used to find out the amino acids, but the amino acid sequence can't be used to find out the DNA sequence, because of the degenerate code.
    • DNA hybridisation:
      • Sections of DNA are used- whole strands are too long.
      • Heat is used to separate and mix the two strands- forming a hybrid.
      • The level of hybridisation indicates how related they are.
    • Complete hybridisation- organisms are identical, they have complementary bases
    • No hybridisation- organisms are unrelated, they have no complementary bases
    • The early days of estimating genetic diversity:
      • Scientists observed visual features in a population and the number of organisms with that particular feature.
      • Different alleles determine different characteristics, so a wide variety of each characteristic indicates high allele numbers and genetic diversity.
    • Gene technology can now measure genetic diversity directly:
      • Different alleles of the same gene have slightly different DNA base sequences which can be compared within individuals in a population to identify the number of those gene alleles.
      • Different alleles produce slightly different mRNA base sequences and proteins with slightly different amino acid sequences- which are easy to compare.
    • Gene technologies can get more accurate estimates of genetic diversity within populations/ species than traditional ways of comparing observable characteristics and features.