The Precambrian Earth
Practice Test
1.
The inner and outer core, mantle, and crust of Earth all have __________.
a.
different densities
b.
have the same specific gravity
c.
the same densities
d.
been rigid since the formation of Earth
2.
What was the original composition of Earth's atmosphere?
a.
water vapor and methane
b.
nitrogen and carbon dioxide
c.
ammonia and hydrogen
d.
hydrogen and helium
3.
What process is primarily responsible for the formation of Earth's oceans?
a.
evolution
b.
outgassing
c.
sea-floor spreading
d.
plate tectonics
4.
Minerals with low densities crystallize from a magma at __________ denser minerals do.
a.
hotter temperatures than
b.
cooler temperatures than
c.
always 10 degrees less than
d.
the same temperature as
5.
What evidence supports the hypothesis that Earth is 4.6 billion years?
a.
the age of rocks from the Moon
b.
the age of zircon grains in granitic crustal rocks
c.
all of the above answers are correct
d.
the age of meteorites
6.
According to the map, which areas of North America were most affected by the formation of the Canadian Shield?
a.
the Southwest
b.
the Pacific Coast
c.
the Midwest
d.
Alaska
7.
How were asteroids and meteorites a heat source for Precambrian Earth?
a.
Their impact on Earth generated energy.
b.
Their bombardment of Earth caused them to sink to the core.
c.
Their gravitational contraction generated energy.
d.
Their radioactive decay of isotopes generated energy.
8.
Fossils of __________ from late Proterozoic rocks are found in all parts of the world.
a.
the Burgess Shale fauna
b.
trilobites
c.
corals
d.
the Ediacaran fauna
9.
What event caused the extinction of acritarchs near the end of the Proterozoic?
a.
global warming
b.
the Varagnian glaciation
c.
formation of ozone
d.
outgassing
10.
What substance in Earth's atmosphere protects organisms from UV radiation?
a.
methane
b.
ozone
c.
ammonia
d.
water vapor
11.
__________ are rocks that have alternating bands of fine-grained quartz and iron oxides.
a.
All Archean rocks
b.
Sedimentary rocks
c.
Red beds
d.
Banded iron formations
12.
What are areas called that contain cores of Archean and Proterozoic rock?
a.
continental crust
b.
Archean shields
c.
Canadian shields
d.
Precambrian shields
13.
The oldest rocks on Earth are __________.
a.
1.6 to 1.8 million years old
b.
1 to 2 billion years old
c.
3.96 to 3.8 billion years old
d.
3.5 billion years old
14.
The energy and nutrients necessary for the origin of life can be found near __________.
a.
magma chambers
b.
transform faults
c.
trenches
d.
hydrothermal vents
15.
Which type of cell shown in the figure existed first?
a.
A
b.
it is impossible to tell
c.
B
d.
both came into existence at the same time
16.
What were the type of life-forms that existed before the Proterozoic?
a.
prokaryotes
b.
fungi
c.
algae
d.
eukaryotes
17.
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
a.
550 million years go
b.
3 billion years ago
c.
600 million years ago
d.
1 billion years ago
18.
What was the composition of Earth's first crust?
a.
feldspar
b.
iron and quartz
c.
feldspar, quartz, and mica
d.
iron- and magnesium-rich minerals
