Prokaryotes and Eukaryotes

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Prokaryotes and Eukaryotes
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Prokaryotes

• Prokaryotes (pro- means before, and -karyote
  means nucleus)
• First type of cells to evolve
• Very small (size of mitochondria)
• Unicellular
• Two Types Archaea and Eubacteria
• Cell Division/Reproduction Asexual via Binary
  Fission

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Prokaryote Shape Common shapes rod shaped,
spherical, or spiral
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Prokaryote Structure

• Components
• cell membrane
• cell wall
• ribosomes
• flagella or cilia
• nucleoid
• cytoplasm
• capsule
• No membrane bound organelles

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Prokaryote Genetic Information

• Single, circular chromosome of DNA.
• May also have plasmids.
• small pieces of DNA with additional genes

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EUKARYOTES

• Emerged 1.6-2.1 Billion years ago
• Characteristics
• Complex structure with Nucleus and Membrane-Bound
  Organelles
• 20-50 micrometeres, but up to meters in length
• Unicellular and Multicellular

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Discussion

• If all cells originate from other cells, how do
  you think eukaryotes came about?
• Endosymbiotic theory - states that some
  eukaryotic organelles evolved from prokaryotes.
• For example, some of the organelles found in
  eukaryotes originated as prokaryotic cells that
  came to reside within a host cell. The host and
  prokaryotic cells benefited from each other and
  eventually resulted in this evolutionary change
  of eukaryote cells.

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Types of Eukaryotes

• Unicellular (Protozoa)
• Protists
• paramecium, amoebae
• Fungi
• yeast
• Multicellular (Metazoa)
• Fungi
• Plants
• Animals
• Reproduction for ALL eukaryotes may be asexual or
  sexual.