Glencoe Online Science Quiz Chapter

Section #: 22.3 Formation of the Atmosphere and Oceans

Practice Test


	1.	Why don't Archean and Proterozoic rocks have iron oxides?

	a.	there weren't any stromatolites at that time
	b.	there wasn't any free oxygen in the atmosphere
	c.	there wasn't any iron in rocks of that age
	d.	there was too much iron to be oxidized
Hint

According to the dates given in the table, when would oxygen start appearing in Earth's atmosphere?

Event Or First Evidence In Fossil Record	Approximate Geological Time
Bacteria	3 b.y.b.p
Green algae	1 b.y.b.p
Jellyfish	600 m.y.b.p
Ediacara organisms	550 m.y.b.p
Eurypterids*	510 m.y.b.p
Horn corals*	500 m.y.b.p
First vertebrates	480 m.y.b.p
Spiders	400 m.y.b.p
Sharks	400 m.y.b.p
First jawed fish*	380 m.y.b.p
Ferns	350 m.y.b.p
Earthworms	300 m.y.b.p
Great Permian Extinction Event	250 m.y.b.p
Drastic geographic and climatic changes	248 m.y.b.p
First dinosaurs*	220 m.y.b.p
First mammals	210 m.y.b.p
Ginkgo biloba	200 m.y.b.p
Abundant ammonites*	180 m.y.b.p
Archaeopteryx*	140 m.y.b.p
First flowering plants	120 m.y.b.p
Ants	100 m.y.b.p
Cretaceous-Paleogene Extinction Event	66 m.y.b.p
Camel	35 m.y.b.p
Grass	20 m.y.b.p
Australopithecus afarensis (“Lucy”)	4 m.y.b.p


	3.	What substance in Earth's atmosphere protects organisms from UV radiation?


	4.	What was the original composition of Earth's atmosphere?


	5.	__________ are rocks that have alternating bands of fine-grained quartz and iron oxides.


	6.	What process is primarily responsible for the formation of Earth's oceans?