Fossil Layers Show Change - Middle School Life Science
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Identify the most likely cause if fossils in a layer are mixed from very different habitats and ages.
Identify the most likely cause if fossils in a layer are mixed from very different habitats and ages.
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Reworking (older fossils eroded and redeposited). Erosion can mix fossils from different sources into one deposit.
Reworking (older fossils eroded and redeposited). Erosion can mix fossils from different sources into one deposit.
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What does a gradual change in a fossil trait across successive layers most strongly indicate?
What does a gradual change in a fossil trait across successive layers most strongly indicate?
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Gradual evolution within a lineage. Progressive changes through layers show evolutionary transitions.
Gradual evolution within a lineage. Progressive changes through layers show evolutionary transitions.
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Identify the best conclusion if older layers show simple shells and younger layers show more complex shells.
Identify the best conclusion if older layers show simple shells and younger layers show more complex shells.
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Shell-bearing organisms changed over time toward greater complexity. Progressive fossil changes demonstrate evolutionary advancement.
Shell-bearing organisms changed over time toward greater complexity. Progressive fossil changes demonstrate evolutionary advancement.
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Which statement best describes what the fossil record in rock layers shows about life on Earth?
Which statement best describes what the fossil record in rock layers shows about life on Earth?
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Life has changed over time, with species appearing and going extinct. The fossil record documents evolution and extinction throughout Earth's history.
Life has changed over time, with species appearing and going extinct. The fossil record documents evolution and extinction throughout Earth's history.
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Which layer is youngest in an undisturbed sequence labeled (bottom to top) 1, 2, 3, 4?
Which layer is youngest in an undisturbed sequence labeled (bottom to top) 1, 2, 3, 4?
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Layer 4. The topmost layer in a sequence is the most recently deposited.
Layer 4. The topmost layer in a sequence is the most recently deposited.
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Identify the correct conclusion: Layer A is below Layer B in undisturbed strata. Which is older?
Identify the correct conclusion: Layer A is below Layer B in undisturbed strata. Which is older?
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Layer A is older than Layer B. Applies the law of superposition: lower layers formed first.
Layer A is older than Layer B. Applies the law of superposition: lower layers formed first.
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What is the principle of faunal succession used for when comparing fossil layers?
What is the principle of faunal succession used for when comparing fossil layers?
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To match the relative ages of layers using fossil assemblages. Similar fossil groups indicate similar time periods across locations.
To match the relative ages of layers using fossil assemblages. Similar fossil groups indicate similar time periods across locations.
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What does it suggest if marine fossils are found in a layer above layers with land-plant fossils?
What does it suggest if marine fossils are found in a layer above layers with land-plant fossils?
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The environment changed to marine (sea level rose). Marine transgression occurred, flooding previously terrestrial areas.
The environment changed to marine (sea level rose). Marine transgression occurred, flooding previously terrestrial areas.
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What is an index fossil?
What is an index fossil?
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A widespread, short-lived species used to date layers. Must be geographically widespread but existed for a brief geological period.
A widespread, short-lived species used to date layers. Must be geographically widespread but existed for a brief geological period.
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What principle states that, in undisturbed rock layers, lower layers are older than higher layers?
What principle states that, in undisturbed rock layers, lower layers are older than higher layers?
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Law of superposition. In undisturbed sequences, sediments accumulate over time with newest on top.
Law of superposition. In undisturbed sequences, sediments accumulate over time with newest on top.
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Which order is correct for undisturbed layers: oldest-to-youngest or youngest-to-oldest from bottom to top?
Which order is correct for undisturbed layers: oldest-to-youngest or youngest-to-oldest from bottom to top?
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Oldest-to-youngest from bottom to top. Superposition principle places oldest rocks at the base of sequences.
Oldest-to-youngest from bottom to top. Superposition principle places oldest rocks at the base of sequences.
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What does it indicate when new fossil species first appear in higher rock layers above older species?
What does it indicate when new fossil species first appear in higher rock layers above older species?
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Evolutionary change over time (new species evolved). Shows descent with modification from ancestral forms below.
Evolutionary change over time (new species evolved). Shows descent with modification from ancestral forms below.
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What is the main limitation of using fossil layers for relative age comparisons?
What is the main limitation of using fossil layers for relative age comparisons?
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It does not provide an exact numerical age. Fossils show sequence but require radiometric dating for absolute ages.
It does not provide an exact numerical age. Fossils show sequence but require radiometric dating for absolute ages.
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What is relative dating?
What is relative dating?
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Determining whether rocks are older or younger, not exact age. Establishes sequence of events without numerical dates.
Determining whether rocks are older or younger, not exact age. Establishes sequence of events without numerical dates.
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Which pattern best supports punctuated equilibrium: gradual change or long stasis with sudden change?
Which pattern best supports punctuated equilibrium: gradual change or long stasis with sudden change?
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Long stasis with sudden change. Theory proposes evolution occurs in rapid bursts between stable periods.
Long stasis with sudden change. Theory proposes evolution occurs in rapid bursts between stable periods.
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Which option is the best evidence that two separated rock columns formed at the same time: same rock type or same index fossil?
Which option is the best evidence that two separated rock columns formed at the same time: same rock type or same index fossil?
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Same index fossil. Index fossils provide temporal correlation; rock types can persist through time.
Same index fossil. Index fossils provide temporal correlation; rock types can persist through time.
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What is an unconformity in a sequence of rock layers?
What is an unconformity in a sequence of rock layers?
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A gap in the rock record from erosion or nondeposition. Represents missing time when rocks were eroded or never deposited.
A gap in the rock record from erosion or nondeposition. Represents missing time when rocks were eroded or never deposited.
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Identify the most likely explanation for a sudden disappearance of many species at one layer boundary.
Identify the most likely explanation for a sudden disappearance of many species at one layer boundary.
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A mass extinction event. Simultaneous disappearances indicate catastrophic environmental change.
A mass extinction event. Simultaneous disappearances indicate catastrophic environmental change.
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What does it suggest if the same index fossil is found in two separate rock layers?
What does it suggest if the same index fossil is found in two separate rock layers?
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The layers are the same relative age. Index fossils indicate contemporaneous deposition across different locations.
The layers are the same relative age. Index fossils indicate contemporaneous deposition across different locations.
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Which type of fossil is most useful for correlating rock layers across long distances?
Which type of fossil is most useful for correlating rock layers across long distances?
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Index fossils. Their wide distribution and short existence make them ideal time markers.
Index fossils. Their wide distribution and short existence make them ideal time markers.
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What is the term for using fossil content to compare the relative ages of rock layers?
What is the term for using fossil content to compare the relative ages of rock layers?
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Biostratigraphy (relative dating with fossils). Uses fossil assemblages to determine relative ages of rock layers.
Biostratigraphy (relative dating with fossils). Uses fossil assemblages to determine relative ages of rock layers.
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What is the term for matching rock layers of the same age using fossils and rock characteristics?
What is the term for matching rock layers of the same age using fossils and rock characteristics?
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Correlation. Process of matching contemporaneous layers across different locations.
Correlation. Process of matching contemporaneous layers across different locations.
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What does it suggest if land-animal fossils replace marine fossils upward through the layers?
What does it suggest if land-animal fossils replace marine fossils upward through the layers?
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The environment became more terrestrial (sea level fell). Marine regression exposed seafloor for terrestrial colonization.
The environment became more terrestrial (sea level fell). Marine regression exposed seafloor for terrestrial colonization.
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What is stasis in the fossil record?
What is stasis in the fossil record?
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Little or no change in a species over long time spans. Species remain morphologically unchanged for extended geological periods.
Little or no change in a species over long time spans. Species remain morphologically unchanged for extended geological periods.
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Identify what a missing set of layers between older and younger rocks most likely represents.
Identify what a missing set of layers between older and younger rocks most likely represents.
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An unconformity (missing time). Gap indicates erosion removed layers or deposition ceased temporarily.
An unconformity (missing time). Gap indicates erosion removed layers or deposition ceased temporarily.
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