Geologic Time Scale Flashcards
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Earliest life forms (such as ___) were influenced by the climates produced by the ______ ______ and oceans of Earth
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Cyanobacteria, forming atmosphere
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During the Precambrian time ____ ____ was one of the most natural events but lava flows, ash clouds in the atmosphere, and heat made conditions for life forms ________. Those simple life forms did/did not survive.
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Volcanic Activity, extremely difficult, did not
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True or False: Very explosive volcanic activity can send ash and dusty high into the atmosphere where it is carried great distances around the Earth
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True
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True or False and what makes the sentence true: The sun can not be blocked for long periods of time. This violent type of activity can not disrupt many of Earth's processes and ultimately the life forms that depend on those processes.
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False: the sun CAN be blocked and it CAN disrupt many of Earth's processes
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Life on land ____ ___ ___ in the tropical climates and warm shallow seas during which time period
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Developed and Flourished and the Paleozoic Era
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Throughout what era as different land environments formed and ___ levels changed new life forms developed.
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Paleozoic Era and Sea Levels
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Life forms that could not adapt or find suitable conditions (especially ___species) disappeared as a result of _____
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Marine Species and Pangaea
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As continents collided and mountains built up due to ___________, volcanoes also formed. _____ _____ continued to be common in the Paleozoic Era.
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Plate tectonics and Volcanic activity
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Began with the 1. (such as ___ and brachiopods) continued to develop 2. early vertebrate ___ 3. arachnids and ____ 4. 1st ____ and near the era's end the ____ became dominant (Paleozoic Era)
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early invertebrates, trilobites, fish, insects, amphibians, reptiles
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Early land plants included: ___ ____, ____, ____-____ ____
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simple mosses, ferns, cone-bearing plants
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By the end of the Paleozoic Era, ____ ___ were common.
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Seed plants
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The mass extinction caused by ____. Most ____ invertebrates and _____ disappeared.
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Pangaea, marine, amphibians
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What time period were Cyanobacteria, oxygen being a major atmospheric gas, shielding of Earth from ultraviolet rays, complex organisms, and invertebrates in?
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Precambrian Time
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What time period were organisms with hard parts, fish, amphibians, reptiles and Pangaea in?
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Paleozoic Era
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What goes through photosynthesis and produces oxygen?
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Cyanobacteria
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Were there a lot of fossils in the Precambrian Time? Why?
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No because there weren't many organisms with hard parts they were mostly invertebrates
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The longest geologic time are called
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Eons
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The division of Earth's history into time units makes up the...
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Geologic Time Scale
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A group of organisms that reproduce only with members of their group is a...
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Species
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Pangaea formed during what time period?
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Paleozoic
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A subdivision of eras is called ____ are characterized by the types of life existing worldwide
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Periods
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This helps scientists divide Earth's history into time units
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Fossils
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The oldest rocks on earth contain _____ fossils
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Only a few
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What is the longest part of Earth's history?
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Precambrian
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Cyanobacteria are _____ bacteria thought to be one of the earliest life forms on Earth.
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Blue-green
