A Trip Through Geological Time Chapter 4 Test Earth Science

The earliest form of life known on Earth was

A _____is a ball of dust, gas and ice that orbits the sun

All of these are parts of Earh's eras except

In the Paleozoic, the center of Pangea was probably

The time it takes half of the radioactive atoms in a sample of radioactive element to decay is

What are fossils?

What has the study of fossils allowed scientists to do?

Footprints usually occur in sedimentary rock

The law of superpostion helps determine the absolute age of a rock layer

Sometimes layers of rock are overturned so much that the youngest layers are on the bottom

Geologists divide Earth's long history into smaller units called the Geological Time Scale

Earth's earliest atmosphere lacked which gas that is necessary for life?

The relative age of a rock is

Geologists use radioactive dating to

Geologists have 2 ways to find the age of a rock.  They use relative and _____age

An ______is a gap in the geological record where rock layers have been lost due to erosion

All of these are a type of fossil except

Jawless fish were Earth's first ________or animals with backbones.

The  first organism to live partly on land were

A _____fossil forms when dissolved materials replace the remians of an organism and then harden

During the Cambrian Explosion that began the Paleozoic Era, many new life forms evolved that

When dinosaurs became extinct ________had a chance to become abundant