Carl Linnaeus classified living organisms into kingdoms. Later, Carl Woese introduced a new classification system called the 'three-domain system' based on chemical analysis.
a.[2]
Which two of the following are domains in Woese's three-domain system? Tick (✓\checkmark✓) two boxes.
- Bacteria
- Prokaryotes
- Protists
- Archaea
- Fungi
b.[2]
Fossils provide valuable evidence of how organisms have changed over millions of years.
What is a fossil?
c.[1]
The dinosaur footprint shown above is a trace fossil. How was this type of fossil formed? Tick (✓\checkmark✓) one box.
- The animal’s foot was preserved intact by being frozen in ice.
- The animal left an imprint in soft mud which hardened into rock over time.
- The bones of the foot were slowly replaced by minerals over a long period.
d.[2]
Dinosaurs became extinct millions of years ago. Give two factors that can cause a species to become extinct.