Exam 19: Earths Evolution Through Geologic Time

The_________ era is known as the "age of flowering plants."

This least understood eon of Earth's history has not been subdivided into epochs.

Mammals became the dominant land animals during the_________ era.

The Precambrian rock record indicates that much of Earth's first free oxygen combined with_________ dissolved in water.

One hypothesis for the extinction that took place at the end of the Mesozoic is that a large_________collided with Earth.

The age of Earth is about _________.

Which one of the following represents the greatest expanse of geological time?

Due to a virtual absence of land plants and certain animals, fossil fuels are notably absent in _________rocks.

Earth's primitive atmosphere evolved from gases __________.

The development of_________ , organisms that reproduce sexually and have cells that contain nuclei, may have increased dramatically the rate of evolutionary change.

The beginning of the Phanerozoic marks an important event in animal evolution-the appearance of organisms with_________ .

Modern human evolution takes place during the ___________ Period of the_________ Era.

On continents, large "core areas" of Precambrian rocks, called_________ , dominate the surface.

The _________Eon spans about 88% of Earth's history.

As the solar system began forming, the first materials to condense into small particles were __________ and helium.

By the_________ period, large tropical swamps extended across North America, eventually becoming the vast coal deposits of today.

_________means "planets in the making."

The_________ were the dominant trees of the Mesozoic Era.

During the late Paleozoic, the present- day North America, Europe, western Asia, Siberia, and perhaps China formed the northern continent of __________ .

The first true terrestrial animals were the _________.