Chapter 22

Question 1

the earth is ___ years old

Answer 1

4.6 billion

Question 2

oldest fossils are ___ years old

Answer 2

3.5 billion

Question 3

chemical evidence of life going back ___ years

Answer 3

3.8-3.9 billion

Question 4

the early earth had… (5)

Answer 4

• little oxygen
• was subjected to meteor showers
• considerable volcanic activity
• electrical storms
• intense ultraviolet radiation

Question 5

what is the chemical evolution of life (4)

Answer 5

• 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

Question 6

the earliest known mammal from the triassic period

Answer 6

megazostrodon

Question 7

the earliest feathered, bird-like, animal; from the Jurassic Period

Answer 7

archaeopteryx

Question 8

___ added oxygen to the atmosphere allowing for the evolution of ___

Answer 8

• cyanobacteria

- eukaryotic cells

Question 9

during the early Cambrian Period most animal Phyla evolved, this is called the ___

Answer 9

Cambrian explosion