Classification

• What is classification in biology?

  Organising living organisms into groups
• Why do scientists classify organisms?

  To identify similarities and differences
• What was the traditional method of classifying organisms based on?

  Visible characteristics like number of legs
• What do natural classification systems use to classify organisms?

  Information about how closely related organisms are
• How do scientists determine how closely related organisms are?

  By examining their structures in detail
• Into how many kingdoms are living things divided in natural classification systems?

  Five kingdoms
• What are the hierarchical groups in natural classification systems?

  Kingdom, phylum, class, order, family, genus, species
• What does the species group contain?

  Only one type of organism
• How has technology improved classification in biology?

  It allows better understanding of organism relationships
• What invention helped scientists classify organisms many years ago?

  The microscope
• What can scientists examine with a microscope?

  Small structures within organisms
• What is molecular phylogenetics?

  A new area studying DNA sequences
• What does DNA sequencing allow scientists to do?

  Look at the sequence of DNA bases
• What does a more similar DNA base sequence indicate?

  Organisms are more closely related
• What percentage of DNA sequence is similar between humans and chimpanzees?

  About 94%
• What does the similarity in DNA suggest about humans and chimpanzees?

  They are closely related
• What are the main differences between artificial and natural classification systems?

  • Artificial classification: based on arbitrary traits
  • Natural classification: based on evolutionary relationships