Download Notes - Endosymbiotic Theory

Endosymbiotic
Theory
The Endosymbiotic Theory

Review:
 What
is a theory?
 What is the difference between prokaryotic and
eukaryotic cells?

The endosymbiotic theory is the idea that a
long time ago, prokaryotic cells engulfed
other prokaryotic cells by endocytosis. This
resulted in the first eukaryotic cells.
 First
proposed by Lynn Margulis
 Explains the origin of eukaryotic cells
 Explains the origin of certain membrane-bound
organelles
What Exactly Happened?
Chloroplast
Heterotrophic
bacteria
Ancient Prokaryotes
Nuclear
envelope
evolving
Plants and
plant-like
protists
Photosynthetic
bacteria
Mitochondrion
Primitive Autotrophic
(Photosynthetic) Eukaryote
Animals, fungi, and
animal-like protists
Ancient Heterotrophic
Prokaryote
Primitive Heterotrophic
Eukaryote
Membrane-Bound Organelles

Mitochondria
(Animals) membranebound organelle that
produces energy for
the cell

Chloroplast (Plants)
membrane-bound
organelle that captures
sunlight and uses it to
make food for the cell
Evidence in support of the
endosymbiotic theory:

Similarities between mitochondria,
chloroplasts, & prokaryotes:
Circular DNA
2. Ribosomes
3. Binary fission
1.
Binary Fission