Endosymbiotic theory

Honors Biology

What was is

The idea that eukaryotic cells advanced from prokaryotic cells and lived in symbiosis

Evidence

• Mito and Chloro are roughly the same size as prokaryotic cells

• Have two membranes

• Have their own dns

• Can grow and divide on their own

Why this order

• Animal cells ONLY have mitochondria

• Plant cells have Mitochondria AND Chloroplast

• More likely to GAIN 1 organelle then another vs gain 2 and lose 1

step 1

Prokaryotes existed first

step 2

in some large prokaryotes, the cell membrane folded inward to make “pockets” inside the cell

step 3

the infolded cell membrane surrounded the cells DNA to make the nucleus

step 4

Some primitive eukaryotes engulfed a small energy-producing prokaryotes (mitochondria and chloroplast)

step 5

some ancient animal cells engulfed a small photosynthetic prokaryote