Chapter 22 Flashcards
1
Q
the earth is ___ years old
A
4.6 billion
2
Q
oldest fossils are ___ years old
A
3.5 billion
3
Q
chemical evidence of life going back ___ years
A
3.8-3.9 billion
4
Q
the early earth had… (5)
A
- little oxygen
- was subjected to meteor showers
- considerable volcanic activity
- electrical storms
- intense ultraviolet radiation
5
Q
what is the chemical evolution of life (4)
A
- formation of organic molecules
- simple organic molecules formed into chains of molecules (polymers) including proteins and nucleic acids
- the organic polymers may have arranged into drop-shaved protobionts- early metabolism evolved
- the final stage would have been the origin of heredity
6
Q
the earliest known mammal from the triassic period
A
megazostrodon
7
Q
the earliest feathered, bird-like, animal; from the Jurassic Period
A
archaeopteryx
8
Q
___ added oxygen to the atmosphere allowing for the evolution of ___
A
- cyanobacteria
- eukaryotic cells
9
Q
during the early Cambrian Period most animal Phyla evolved, this is called the ___
A
Cambrian explosion
