Biology Topic Practice
The Three-Domain System
As our knowledge of genetics grew, scientists needed an even broader way to classify life.
Who proposed the "Three-Domain System"?
What is The Three-Domain System?
"The three-domain system is a biological classification introduced by Carl Woese that divides cellular life forms into Archaea, Bacteria, and Eukaryote domains."
Question 1
What is evolution?
Question 2
Why do modern classification systems use evolutionary relationships?
Question 3
What is speciation?
Question 4
What is extinction?
Broad Classification
Archaea (primitive bacteria usually living in extreme conditions).
Bacteria (true bacteria).
Eukaryota (including protists, fungi, plants, and animals).
Exam Tip
Carl Woese used chemical analysis (rRNA) to prove that some bacteria were fundamentally different from others.
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