Endosymbiotic Theory

Oh, I am very excited!!!   This is one of my favorite topics of the year!

ENDOSYMBIOTIC THEORY

An endosymbiont is a cell that lives inside another cell with mutual benefit

Eukaryotic cells are believed to have evolved from early prokaryotes that were engulfed by phagocytosis

The engulfed prokaryotic cell remained undigested as it contributed new functionality to the engulfing cell (e.g. photosynthesis)

Over generations, the engulfed cell lost some of its independent utility and became a supplemental organelle

EVIDENCE TO SUPPORT THE ENDOSYMBIOTIC THEORY

• Membranes- double membrane

• Antibiotic susceptibility

• Division (replicate on its own instructions)

• DNA (single circular DNA)

• Ribosomes (size like prokaryote)

• Tail (evidence of a formal tail)  

Mnemonic to remember: MAD DR T