Biology chapter 19 Answers – Flashcards
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Fossil
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Preserved remains to traces of ancient organisms.
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Endosymbiotic theory
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Theory that proposes that eukaryotic cells formed from a symbiotic relationship among several different prokaryotic cells.
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The Rock formations are
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Sedimentary rocks Igneous rocks Metamorphic rocks
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Biogenesis
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The production of living organisms from other living organisms.
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Carbon, radiometric, or radiocarbon dating
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Method for determining the age of a sample from the amount of a radioactive isotope to the nonradioactive isotope of the same element in a sample
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Scientists who specialize in the study of fossils are called
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Paleontologists
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Sedimentary rocks usually form when layers of small particles are compressed
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Under water
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Using C-14 to analyze rock layers
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Is a method of estimating relative age
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Half-life is the time required for half the atoms in a radioactive sample to
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Decay
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According to the theory of plate tectonics,
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Earth's continents move very slowly
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How does relative dating enable paleontologists to estimate a fossil's age?
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Relative dating allows paleontologists to determine whether a fossil is older or younger than other fossils.
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Explain how radioactivity is used to date rocks.
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Radiometric dating uses the proportion of radioactive to stable isotopes to calculate the age of a sample
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What is the geologic time scale, and how was it developed?
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The geologic time scale is based on both relative and absolute dating. The major divisions of the geologic time scale are eons, eras, and periods
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How have the activities of organisms affected Earth's environment?
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The actions of living organisms over time have changed conditions in the land, water, and atmosphere of planet Earth
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Earth's early atmosphere contained little or no
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Oxygen
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In their experiment that modeled conditions on ancient Earth, Miller and Urey used electric sparks to simulate
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Lightning
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Outlines of ancient cells that are preserved well enough to identify them as prokaryotes are
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Microfossils
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How long ago was the Earth formed?
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4.6 billion years ago
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When the Earth formed what did gravity do?
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It pulled the densest elements to the center of the planet
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How long did it take for solid crust to form on the surface of the earth?
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Approximately 500 million years
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Why do most organisms not end up as fossils?
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Because they decompose before they become fossils
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List the six categories of fossil types
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1. trace fossil 2. molds and casts 3. replacement 4. petrified or permineralized 5. Amber 6. original material
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What is a trace fossil?
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Any indirect evidence left by an organism. Example: footprints
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What is a mold?
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A mold is an impression of an organism.
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What is a cast?
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A cast is a mold filled with sediment
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What is replacement?
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The original material of an organism is replaced with mineral crystals that can leave detailed replicas of hard or soft parts
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What are petrified or permineralized fossil types?
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Empty pore spaces are filled in by minerals. Example: petrified wood
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What is Amber?
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Preserved tree sap traps an entire organism. The sap hardens into Amber and preserves the trapped organism.
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What is original material?
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Mummification or freezing preserves original organisms.
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Where are nearly all fossils formed?
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In sedimentary rock
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What is relative dating?
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A method used to determine the age of rocks by comparing them with those in other layers
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What is the geological time scale?
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A model that expresses the major geological and biological events in Earth's history
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List the three eras.
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1. Paleozoic era 2. Mesolithic era 3. Cenozoic era
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What are the three periods of the Cenozoic era?
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1. Quaternary 2. Neogene 3. Paleogene
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What are the three periods of the Mesozoic era?
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1. Cretaceous 2. Jurassic 3. Triassic
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What are the six periods of the Paleozoic era?
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1. Permian 2. Carboniferous 3. Devonian 4. Silurian 5. Ordovician 6. Cambrian
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Nearly 90% of Earth's entire history is part of what time period?
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Precambrian
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Fish, land plants, and insects appeared during what periods?
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Ordovician and Silurian periods
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What period did the first tetrapods emerge in?
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The Devonian period
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What is the Cambrian explosion?
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The time period when most major animal groups diversified
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A mass extinction ended what era?
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The Paleozoic era
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What percentage of species became extinct during the Paleozoic era?
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60%-75% of the species became extinct
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When did mammals and dinosaurs first appear?
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The Triassic period of the Mesozoic era
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What do plate tectonics describe?
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The movement of several large plates that make up the surface of the earth
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Put the Eras in order from oldest to youngest
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1. Precambrian 2. Paleozoic 3.Mesozoic 4.Cenozoic
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The reason scientists can relatively date rocks is due to the law of _____
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Superposition
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What organisms were alive in the mesozoic era?
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Dinosaurs, mammals, and birds
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Who created an experiment to disapprove spontaneous generation? What was his experiment?
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Francesco Redi conducted an experiment using raw meat. He put raw meat in a beaker and covered it. He put raw meat in another beaker and did not cover it.
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What was the independent variable in Redi's experiment?
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Time
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What was the dependant variable in Redi's experiment?
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The number of flies
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What was the control group in Redi's experiment?
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The beaker without the lid
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What was the experimental group Redi's experiment?
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The beaker with the lid on
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What was the conclusion in Redi's experiment?
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He disproved spontaneous generation. Life cannot arise from nonlife.
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What theory did Louis Pasteur come up with?
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The theory of biogenesis
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What is the theory of biogenesis?
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Only living organisms can produce other living organisms
