kingdom

• Plants

  • Multicellular
  • Autotrophs (use photosynthesis)
  • Estimated 300,000 species
• Protists

  • Nearly all are unicellular
  • Some are autotrophs, some are heterotrophs
  • Some are pathogens (e.g. malaria)
• Viruses

  • Tiny particles, not cells
  • Require living cells to reproduce (parasites)
  • All are pathogens
• Viruses are not considered living organisms, they are not classified into any of the kingdoms
• Viruses are 10-100 times smaller than prokaryotic cells