Endosymbiotic Theory

endosymbiotic theory

• hypothesis explaining how eukaryotic cells and organelles originated from prokaryotic cells

• believed that eukaryotic cells evolved from prokaryotic cells

  • chloroplasts and mitochondria started out as small prokaryotes

  • bigger prokaryotes engulfed these smaller prokaryotes

  • these smaller prokaryotes did not digest, therefore they lived in symbiosis with the bigger cell, creating eukaryotes

prokaryotic cells

• small and simple

• 0.1 to 5.0 um in size

• unicellular

• nucleus is absent

• circular DNA

• single haploid chromosome

• lack membrane-bound organelles

• reproduce sexually and asexually

• cells division by binary fission

• examples are bacteria and archaea cells

• have cells plasma membrane

• have cytoplasm

• have ribosomes

• have DNA

eukaryotic cells

• large and complex

• 10 +100 um in size

• unicellular or multicellular

• nucleus is present

• linear DNA

• paired diploid chromosome

• has membrane bound organelles

• mostly reproduce sexually

• cells division by mitosis

• examples are plants and animal cells

• have cell plasma membrane

• have cytoplasm

• have ribosomes

• have

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