Exam 12: Earths Evolution Through Geologic Time

Many reptile groups became extinct at the close of the Cenozoic era.

Ozone is a constituent of the ________,where it protects life from ultraviolet radiation from the sun.

What organic compounds are essential for DNA and RNA to form?

The decay of radioactive atoms,coupled with heat released by colliding particles,produced at least some melting of Earth's early interior.

Planets in the making are referred to as ________.

Earth's primitive atmosphere evolved from gases ________.

Due to differentiation,the lighter,gaseous materials escaped Earth's interior and became the primitive atmosphere.

During the Cenozoic era,the eastern and western margins of North America experienced similar geologic events.

At the start of the Paleozoic,North America ________.

A major event of the Mesozoic era was the breakup of the supercontinent called Pangaea.

The large outer planets (Jupiter,Saturn,Uranus,and Neptune)contain huge amounts of hydrogen and other light materials as part of their composition.

During the Cambrian,Trilobites developed a flexible exoskeleton which allowed them to ________.

The first elements to form after "Big Bang" were ________.

The Laramide Orogeny at the end of the Mesozoic produced ________.

Preserved rocks in North America are generally less than ________.

The first true terrestrial land animals were the mammals.

The North America craton formed as a result of ________.

A major economic deposit associated with the Cretaceous period is ________.

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

The supercontinent of Pangaea began to break up during the ________ era.