Geography

The beginning of the ________ is marked by the appearance of the first life forms with hard parts.

Started by mynx

During the ________, a great wedge of sediments from the eroding Rockies created the Great Plains.

Started by folubunmi

The supercontinent of Pangaea formed during the ________.

Started by tingc95

A major event of the ________ was the breakup of the supercontinent called Pangaea.

Started by saliriagwu

Fossil fuels are especially abundant in ________ rocks.

Started by RODY.ELKHALIL

Well preserved remains of many tiny organisms extend the record of life back beyond ________ billion years.

Started by vicotolentino

The atmosphere of ________ is composed primarily of carbon dioxide.

Started by luvbio

Much of the original free oxygen in the atmosphere combined with iron dissolved in water to become ________.

Started by leo leo

The salinity of the oceans is ________.

Started by Mr. Wonderful

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

Started by Coya19@aol.com

The bodies of our solar system began forming about ________ billion years ago from an enormous cloud ...

Started by nmorano1

Examine the words and/or phrases below and determine the relationship among the majority of ...

Started by codyclark

Examine the words and/or phrases below and determine the relationship among the majority of ...

Started by gonzo233

The major adaptions that made it possible for mammals to evolve into their modern forms included all ...

Started by dmcintosh

Birds evolved from ________.

Started by joblessjake

Which of the following is modern descendant of the Gymnosperm?

Started by rosent76

What group of animals were the first to leave the ocean to become the first amphibians?

Started by clmills979

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

Started by SGallaher96

An important evolutionary step for reptiles was ________.

Started by jhjkgdfhk

Which type of bacteria thrive in environments that lack free oxygen?

Started by plus1

Which of the following is not a hypothesis for how life began?

Started by asmith134

Scientists have found evidence that life existed at least 3.5 billion years ago ________.

Started by jazziefee

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

Started by cool

At the start of the Triassic, most of the continents were above sea level, and sediments from that ...

Started by cherise1989

By the close of the Paleozoic, all the continents had fused into the single super continent of ________.

Started by Marty