Classification Using DNA or Proteins

• What is the main focus of classification using DNA or proteins?

  Classifying organisms according to evolutionary relationships
• Why is classifying organisms according to their evolutionary relationships not easy?

  It involves complex evolutionary histories
• How do advancements in DNA and molecular technology help in classification?

  They improve accuracy in classifying organisms
• What can new improved technologies in classification lead to?

  New discoveries about evolutionary relationships
• What is the significance of clarifying evolutionary relationships?

  It updates classification systems for accuracy
• What technologies are useful for clarifying evolutionary relationships?

  • Genome sequencing
  • Advances in molecular technology
• What does genome sequencing help determine?

  The entire base sequence of an organism's DNA
• How can the DNA base sequence of one organism be compared to another?

  To see how closely related they are
• What does a higher percentage of similarity in DNA indicate?

  Closer evolutionary relationships between species
• What percentage of DNA do humans and chimps share?

  About 94%
• What percentage of DNA do humans and mice share?

  About 86%
• How has genome sequencing clarified relationships among species?

  • Identified relationships between skunks and mustelids
  • Clarified classifications within the Mustelidae family
• What family do skunks belong to?

  The Mustelidae family
• What was the outcome of classifying skunks in the Mustelidae family?

  It revealed significant differences from other members
• What does significant difference in DNA sequencing indicate about skunks?

  They are distinct from other mustelids
• Into which family were skunks classified?

  The family Mephitidae
• What family do weasels and badgers belong to?

  Mustelidae
• How were skunks classified in relation to the Mustelidae family?

  They were classified until their DNA was revealed
• What significant difference was found in skunks' DNA compared to other Mustelidae members?

  It was significantly different from other members
• Into which family were skunks classified?

  Mephitidae
• What are proteins made of?

  Amino acids
• How is the sequence of amino acids in a protein determined?

  By the base sequence in DNA
• What do related organisms have in common regarding DNA sequences?

  Similar DNA sequences
• What is the relationship between amino acid sequences and proteins in related organisms?

  They have similar amino acid sequences
• How does the similarity of amino acid sequences relate to species classification?

  The more similar, the more closely related they are
• What do similar proteins in different species indicate?

  They are likely closely related
• What happens when antibodies bind to similar proteins?

  They will bind to the same antibodies
• If antibodies recognize a human version of a protein, what will they also recognize?

  Similar proteins from other species
• Which species is recognized by antibodies that bind to human proteins?

  Chimpanzees
• Which species is NOT recognized by antibodies that bind to human proteins?

  Mice
• What do antibodies that recognize human proteins indicate about related species?

  They recognize similar proteins in those species