2. Prokaryotes vs. Eukaryotes
Prokaryotes contain only a Eukaryotes contain a true
nucleoid and no organelles. nucleus and membrane-
bound organelles.
Prokaryotes are simpler and
appear earliest in Earth’s Eukaryotes are more
fossil records. complex, thus appear later.
Symbiont theory: smaller
Size: 1 – 3 μm unicellular organisms were
engulfed and became part
of larger ones, eventually
specialising to become
organelles within the cell.
Evidence: comparable in
size and have their own
DNA (mitochondria)
Size: 10 – 100 μm
