Summary OCR A/AS-Level Biology 2.1.4-7 Prokaryotic and Eukaryotic Cells

Prokaryotic and Eukaryotic
Cells
Similarities
 Plasma membrane
 Cytoplasm
 Ribosomes
 DNA and RNA


Differences
 Prokaryotes are smaller and have smaller ribosomes
 Prokaryotes have no nucleus and free genetic material
 Prokaryotes have no membrane-bound organelles
 Prokaryotes are less developed/more primitive


Endosymbiotic Theory
 Theory that eukaryotes evolved from prokaryotes
 Prokaryotes with an infolded membrane capable of holding ATP invading other
prokaryotes and were engulfed but not digested
 The membrane folded inwards around the invading cell, producing a double membrane
 The invading cells became chloroplasts and mitochondria which share features with
prokaryotes:
o Small ribosomes
o Loops of DNA
o Contain RNA
o Can divide by binary fission