Geologic TimeScale Review

The biggest unit of time on the Geologic Time Scale is 

• an era
• a period
• an eon
• an epoch

Eras a broken into 

• eons
• periods
• epochs
• millions of years

Of the following organisms, which was around (or has been around) for the shortest amount of time?

• Dinosaurs
• Mammals
• Humans
• Reptile

The geologic time scale is divided by major changes or events such as

• mass extinctions
• the extinction of one species
• the development of one new species
• a small temperature change

What is the difference between relative dating and absolute dating?

• Relative dating provides the exact age of a rock, while absolute dating provides a rough estimate of the rock’s age
• Relative dating can estimate a rock’s age only in relation to other objects or events, while absolute dating can provide an actual age
• Relative dating uses several types of radioactive decay to determine an object’s relative age, while absolute dating only uses the halflife of uranium 235
• Relative dating and absolute dating can only determine the rock’s age in relation to other objects or events

What is the primary purpose of index fossils?

• They help scientists determine the absolute age of sedimentary rocks
• The help scientists determine the relative age of rocks
• They help scientists indentify mass extinctions in Earth’s history
• They provide scientists with evidence for the theory of evolution by natural selection

Periods are broken up into smaller chunks of time called?

• Epochs
• Periods 
• Jurrasic
• Ions

The ___________spans about 87% of Earth's history and saw the formation of earth, its atmosphere and the oceans.

• Cenozioc
• Phaneozic
• Paleozoic
• Precambrian

The Phanerozoic Eon consists of the Mesozoic, Cenozoic and _________ Eras?

• Cretaceous
• Devonian
• Paleozoic
• Archaen

The Mesozoic era is known as the "Age of Reptiles"

• True
• False