|Which of the following gases was NOT part of Earth's original atmosphere? ||oxygen|
|The most common Precambrian fossils are ________, layered mounds of calcium carbonate. ||stromatolites|
|The ________ era is known as the "age of flowering plants." ||Cenozoic|
|________ are among the most widespread Paleozoic fossils ||Brachiopods|
|As the solar system began forming, the first materials to condense into small particles were ________ and nickel.
? oxygen - silicon - nitrogen - carbon ? ||none of these|
|Which one of the following represents the greatest expanse of geological time? ||Precambrian|
|During the early Paleozoic era, South America, Africa, Australia, Antarctica, India, and perhaps China comprised the vast southern continent of ________ ||Gondwanaland|
|Which type of bacteria thrive in environments that lack free oxygen ||anaerobic|
|Which era of geologic time spans about 88 percent of Earth's history ||Precambian|
|The ________ means "the Sun in the making." ||protosun|
|Mammals became the dominant land animals during the ________ era ||Cenozoic|
|The ________ period was a time of major extinctions, including 75 percent of amphibian families. ||Permian|
|The beginning of the Cambrian period marks an important event in animal evolution — the appearance of organisms with _______ ||hard parts|
|The era of "ancient life" is the ________ era.
? Cenozoic - Precambian - Neolithic - Mesozoic ?
||none of these|
|Due to a virtual absence of land plants and certain animals, fossil fuels are notably absent in ________ rocks ||Precambian|
|The major source of free oxygen in the atmosphere is from ________ ||green plants|
|The age of Earth is about ________. ||4.5 billion years|
|The Precambrian rock record indicates that much of Earth's first free oxygen combined with ________ dissolved in water.
|Which one of the following does NOT characterize the early development and specialization of the primitive mammals ||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? ||Mercury and Earth|
|Abundant fossil evidence did not appear in the geologic record until about ________ ||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 ________. ||Laurasia|
|Most ________ rocks are devoid of fossils, which hinders correlation of rocks. ||Precambrian|
|The ________ period is sometimes called the "golden age of trilobites." ||Cambrian|
|________ means "planets in the making." ||protoplanet|
|The process in which plants use light energy to synthesize food sugars from carbon dioxide is called ________. ||photosynthesis|
|The beginning of the ________ era is marked by the appearance of the first life forms with hard parts. ||Paleozoic|
|Each continent contains large "core areas" of Precambrian rocks referred to as _______ ||shields|
|By the close of the Paleozoic, all the continents had fused into the single super continent of ________. ||Pangea|
|Earth's primitive atmosphere evolved from gases ________.
||expelled from within|
|The most economically important resource in Cenozoic strata of the Gulf Coast is _______ ||petroleum|
|The waste gas released by plants as they synthesize food sugars from carbon dioxide and water is ______ ||oxygen|
|Most of Earth's iron ore occurs in middle ________ rocks ||Precambrian|
|The first true terrestrial animals were the _______ ||reptiles|
|This least understood era of Earth's history has not been subdivided into briefer time units (according to the book) ||Precambrian|
|During the ________ period, large evaporite deposits of rock salt and gypsum formed in North America.
|The supercontinent of Pangaea began to break up during the ________ era. ||Mesozoic|
|Which era is sometimes called the "age of dinosaurs? ||Mesozoic|
|During the ________ era, the westward-moving North American plate began to override the Pacific plate, eventually causing the tectonic activity that ultimately formed the mountains of western North America ||Mesozoic|
|By the ________ period, large tropical swamps extended across North America, eventually becoming the vast coal deposits of today ||Pennsylvanian|
|One group of reptiles, exemplified by the fossil Archaeopteryx, led to the evolution of _______ ||birds|
|Which period is known as the "age of fishes"? ||Devonian|
|During the Cenozoic, plate interactions gave rise to many events of mountain building, volcanism, and earthquakes in ________ North America ||western|
|The cells of these primitive organisms lack organized nuclei and they reproduce asexually. ||prokaryotes|
|Following the reptilian extinctions at the close of the Mesozoic, two groups of mammals, the marsupials and ________, evolved.
|Cambrian - Mississippian - Jurassic - Devonian ||Jurassic|
|trilobites - brachiopods - fish - dinosaurs ||dinosaurs|
|Cenozoic - Phanerozoic - Mesozoic - Paleozoic ||Phanerozoic|
|The decay of radioactive atoms, coupled with heat released by colliding particles, produced at least some melting of Earth's early interior. ||T|
|We are now living in the Mesozoic era. ||F|
|Most Mesozoic rocks are devoid of fossils; consequently this is the least understood span of Earth's history ||F|
|Probably the single most characteristic feature of the Precambrian is its great abundance of fossil evidence.
|Due to differentiation, the lighter, gaseous materials escaped Earth's interior and became the primitive atmosphere. ||T|
|During the early Paleozoic era, the continent of Gondwanaland included North and South America. ||F|
|The bodies of our solar system began forming about 5 billion years ago from an enormous cloud of minute rocky fragments and gases. ||T|
|The first true terrestrial land animals were the mammals. ||F|
|Earth's original atmosphere, several billion years ago, was similar to the present atmosphere. ||F|
|The Cenozoic era is the age of mammals. ||T|
|The major source of oxygen in Earth's atmosphere is from the decay of plants ||F|
|The supercontinent of Pangaea formed during the late Mesozoic era. ||F|
|Much of the original free oxygen in the atmosphere combined with iron dissolved in water to become iron oxide. ||T|
|During the Cenozoic era, the eastern and western margins of North America experienced similar geologic events. ||F|
|The large outer planets (Jupiter, Saturn, Uranus, and Neptune) contain huge amounts of hydrogen and other light materials as part of their composition.
|Fossil fuels are abundant in Precambrian rocks. ||F|
|A major event of the Mesozoic era was the breakup of the supercontinent called Pangaea. ||T|
|The fault-block mountains of Nevada and Mexico formed during the Cenozoic era. ||T|
|When Earth's primitive surface cooled below water's boiling point, torrential rains slowly filled low areas, forming oceans. ||T|
|Volcanic activity was common in western North America during much of Cenozoic time. ||T|
|The earliest land plants had large, broad leafs to efficiently intercept sunlight. ||F|
|Mammals replaced reptiles as the dominant land animals in the Cenozoic era. ||T|
|A wave of late Pleistocene extinctions rapidly eliminated many large mammals. ||T|
|The beginning of the Precambrian era is marked by the appearance of the first life forms with hard parts. ||F|
|Many reptile groups became extinct at the close of the Cenozoic era. ||F|
|During the Cenozoic era, a great wedge of sediments from the eroding Rockies created the Great Plains.