12. The diagram below shows a colony of prokaryotes, and a single-celled eukaryote. The eukaryote
contains organelles that resemble the three types of bacteria that are found in the prokaryotes. More than
a billion years ago, bacteria like these may have joined with prokaryotes to form cells. Researchers think
that these once free-living prokaryotes became the organelles of the modern day eukaryotes.
COLONY OF PROKARYOTES
EUKARYOTE
Spirochete 4
bacteria
Aerobic
bacteria
Host cell
Photosynthetic
blue-green
bacteria
Which portion of the cell theory does this explain?
A. All organisms have organelles.
B. All cells are made up of bacteria.
C. All organisms are composed of cells.
D. All cells come from pre-existing cells.
Organelles