E & S- The Rock Record

Multiple Choice

Which statement best describes how the geologic time scale is organized?

• Oldest time units at the top, youngest at the bottom

• Oldest time units at the bottom, youngest at the top

• All time units are the same length

• Time units are organized randomly

Open Ended

Explain how fossils help geologists organize Earth's history into time units.

Multiple Select

Which of the following are divisions of the geologic time scale?

• Eon

• Era

• Period

• Epoch

Multiple Choice

Which of the following is the longest span of time in the geologic time scale?

• Era

• Period

• Epoch

• Eon

Multiple Choice

The geologic time scale begins with Earth's formation ___ billion years ago.

• 4.6
• 5.2

• 8.9

• 1.7

Multiple Choice

Which eon is known for making up 90 percent of geologic time and for the formation of Earth?

• Phanerozoic

• Precambrian

• Cenozoic

• Mesozoic

Multiple Select

Select all statements that are true about the eras of the Phanerozoic eon.

• The Paleozoic era is known as 'old life'.

• The Mesozoic era is known as 'middle life'.

• The Cenozoic era is known as 'recent life'.

• The Precambrian era is known as 'ancient life'.

Fill in the Blank

Periods are generally ___ of years in duration.

Fill in the Blank

The Proterozoic Eon was devoid of life until the ___ Era.

Multiple Choice

Which era saw the evolution of land plants and the establishment of land animals?

• Mesozoic era

• Cenozoic era

• Paleozoic era

• Precambrian era

Open Ended

Describe the significance of the mass extinction event at the end of the Paleozoic era.

Multiple Select

Which of the following organisms evolved during the Mesozoic Era?

• Dinosaurs

• Flowering plants

• Mammals

• Coral reefs

Fill in the Blank

The end of the Mesozoic Era is marked by a large ___ event.

Open Ended

What are two major evolutionary milestones that occurred during the Cenozoic Era?

Multiple Choice

The end of which era is marked by the largest extinction event in Earth’s history?

• Cenozoic

• Mesozoic

• Paleozoic

• Precambrian

Multiple Choice

Which is the shortest division of geologic time?

• period

• eon

• era

• epoch

Open Ended

Explain how the presence of certain fossil groups is used to divide geologic time and why other factors like rock type or layer thickness are less important.

Multiple Choice

On what are the divisions of the geologic time scale based?

• Ratio of different rock types present

• Thickness of individual rock layers

• Presence of certain fossil groups

• Composition of sedimentary rock sequences

Multiple Choice

Which era means 'ancient life'?

• Paleozoic

• Mesozoic

• Cenozoic

• Precambrian

Open Ended

Summarize one key concept you learned about the rock record and its importance in understanding Earth's history.