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23 Cards in this Set

  • Front
  • Back
Geologic time is divided into units based upon types of
fossils (organisms)
The longest subdivision in geologic time is a(n)
eon
A life-form in the Precambrian time was
cyanobacteria
Life-forms that existed during the Paleozoic Era are
fish, trilobites, reptiles
Homo sapiens probably appeared ________ years ago.
400,000
Changes in the environment can result in
changes in species
A life-form that evolved during the ____ Era was the dinosaur.
Mesozoic
Plate tectonics may affect organic evolution because movement of plates may cause a change in __________.
the environment
The divison of Earth's history into smaller units makes up the ___________.
geologic time scale
Reptiles evolved from an ancestor of amphibians that developed a(n)
egg with a strong outer shell that kept it from drying out
A ____________ is a group of organisms that only reproduces with other members of their group.
species
This supercontinent formed at the end of the ______________ Era.
Palezoic
The northern part of Pangaea was called _________________.
Gondwanaland
The southern part of Pangaea was called ________________.
Laurasia
Animals with pouches are called
Marsupials
Flowering plants are called
angiosperms
Most life-forms of the Palezoic Era lived in ______________.
oceans/water
The _______________ formed during the Paleozoic Era.
Appalachian Mountains.
Humans first appeared during the _________ Era.
Cenozioc
Pangaea seperated into __________.
two large landmasses
Scientist believe dinosaurs evolved from ___________ during the Mesozoic Era.
reptiles
______ on the geologic time scale are marked by major, striking, and worldwide changes in the type of fossils.
Eras
____________________ proposed the theory of natural selection.
Charles Darwin