44 terms

Science Chapter 11 Geologic Time Review

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Eras are not equal divisions of time while hours are not.
How is the relationship between eons and eras different than the relationship between hours and minutes?
epoch, period, era, eon
Shows the divisions of the geologic time line from least to greatest
gas and dust and gas from volcanoes
These could cause a mass extinction.
There are no fossils of dinosaurs in the rocks above the iridium layers.
What is one reason the presence of iridium leads scientists to hypothesize that meteorite impact caused the mass extinction of dinosaurs?
species adapt to a change in the enviorment
Evolution occurs when__________
A land bridge allows a species to move to a new environment. The species must then adapt to that new environment to survive.
How do land bridges contribute to changes in a species?
the age of the invertebrates
There were so many animals without backbones in the Early Paleozoic that it is often called
Tectonics plates moved in such a fashion that the continents all came together into a super continent.
How was Pangaea formed?
middle Paleozoic
During the________ the Appalachians mountains formed.
Both would eject ash and rock into the atmosphere, reducing temperatures.
Why do scientists hypothesize that either volcanic explosions or a meteorite impact led to the Permian mass extinction?
ocean water flooding a continent
What forms an inland sea?
Middle Paleozoic
Vertebrates begin to appear during which era?
Triassic
When did Pangaea begin to split up?
All the ice caps and glaciers had melted
What was the source of the water for the formation of the Atlantic Ocean?
The rocky Mountains and an inland sea
What two features formed in north America during the Mesozoic Era?
Dinosaurs' tails were directly below their hips, while reptiles have legs that stick out sideways from their bodies
Which is a major difference in the build of dinosaurs and reptiles?
Mammals, dinosaurs, and reptiles.
What existed during the Mesozoic Era?
rocks carried by glaciers
What caused the glacial grooves?
Mammals
The Cenozoic era is something known as the age of the______________
Across land bridged that are now covers with water
Scientist's believe humans first appeared in Africa. How were they able to make their way to North America?
physical changes in species
Changes in the environment result in____________
birds
Today, some scientists think that____________evolved from dinosaurs.
mass extinction of land and sea animals
The end of the Paleozoic Era was signaled by__________
Mesozoic
a life-form that evolved during the____________era was the dinosaur.
the environment
Plate tectonics may affect organic evolution because movement of plates may cause a change in_____________
two large landmasses
Pangaea separated into
egg with a strong outer shell that kept it from drying out
Reptiles evolved from an ancestor of amphibians that developed a___________
geologic time scale
The division of Earth's history onto smaller units makes up the___________
evolve
If a species can adapt to a changing environment, or _____________, its descendants will survive.
plate tectonics
The change in environments that may have occurred at the end of the Paleozoic Era may have been caused by______________
Appalachian Mountains
The______________formed during the Paleozoic Era.
Cenozoic
Humans first appeared during the___________Era.
Africa
The oldest fossil remains of human ancestors have been found on the continent of___________
marsupials
Most mammals in Australia today are___________
Phanerozoic
The Paleozoic, Mesozoic, and Cenozoic eras are all divisions of the____________eon.
heavily armored
Many types of fish in the Middle Paleozoic were_____________
95
Fossil evidence shows that during the mass extinction, _____________ percent of marine-life forms became extinct.
hard body parts
Trilobites are well represented in the fossil record because of their_______________
Reptiles
______________can produce on land, while amphibians need water to reproduce.
Dinosaurs' skeletons
_______________can be distinguished from those other reptiles by the structure of the hips and legs,
Triassic, Jurassic, Cretaceous
Mesozoic Era time periods in order
Paleozoic
The largest mass extinction in earth's history occurred at the end of the_____________era
climate
Plate tectonics may affect organic evolution because movement of plates may cause a change in ______
Theory of Extinction
changing environmental conditions at the end of the Mesozoic Era led to the disappearance of many kinds of organisms in what may have been a domino effect, as organisms at the base of the food chain were killed, sending waves of extinctions through species higher on the food chain that depended on them. one theory is that a large meteorite crashed into earth 65 million years ago.