Which of the following gases was NOT
part of Earth's original atmosphere?
a. water vapor
b. carbon dioxide
e. both a. and c.
____________ are among the most wide
spread Paleozoic fossils.
As the solar system began forming, the first materials to condense into small particles were ________ and nickel.
E) none of these
E none of these
Which one of the following represents the greatest expanse of geological time?
During the early Paleozoic era, South America, Africa, Australia, Antarctica, India, and perhaps China comprised the vast southern continent of ________.
Which type of bacteria thrive in environments that lack free oxygen?
Which era of geologic time spans about 88 percent of Earth's history?
E) none of above
The ________ means "the Sun in the making."
A) solar disk
C) nebular Sun
Mammals became the dominant land animals during the ____era.
The ____________ period was a time of major extinctions, including 75 percent of amphibian families.
The beginning of the Cambrian Period marks an important event in animal evolution - the appearance of organisms with ____________.
c. hard parts
e. none of the above
C hard parts
The era of "ancient life" is the _________ era.
e.none of the above
E none of the above
Due to a virtual absence of land plants and certain animals, fossil fuels are notably absent in ____________ rocks.
e.Paleozoic and Mesozoic
he major source of free oxygen in the atmosphere is from ____________.
C green plants
The age of Earth is about ____________.
a.2 billion years
b.4.5 million years
c.16 million years
d.4.5 billion years
e.195 million years
D 4.5 billion years
The Precambrian rock record indicates that much of Earth's first free oxygen combined with ____________ dissolved in water.
e. none of these
Which one of the following does NOT characterize the early development and specialization of the primitive mammals?
a.increase in size
b.increase in stomach capacity
c.increase in brain capacity
d.specialization of limbs
e.specialization of teeth
B Increase in stomach capacity
As they formed, due to their high temperatures and comparatively weak gravitational fields, which planets were unable to retain appreciable amounts of hydrogen, helium, and ammonia?
a.Jupiter and Neptune
b.Mercury and Earth
c.Uranus and Pluto
d.Jupiter and Uranus
e.Neptune and Uranus
B Mercury and Earth
Abundant fossil evidence did not appear in the geologic record until about ________.
a.5 billion years ago
b.6 million years ago
c.550 million years ago
d.300 million years ago
e.3 billion years ago
C 540 million years ago
During the late Paleozoic, the present-day North America, Europe, western Asia, Siberia, and perhaps China formed the northern continent of ____________.
e.none of the above