When geologists refer to the "Big Five," what are they referring to?
The five largest mass extinctions in Earth's history.
The main causes of the disasters that cause mass extinctions seem to come either from above, in the form of deadly asteroids or comets, or from below, in the form of extreme volcanic activity.
True
Which of the following is the shortest interval of geologic time?
A period
The deadliest of all mass extinctions, which killed off 95% of all living organisms, was the _____.
Permian-Triassic
Which of the following eons has no rock record?
Hadean
What information did geologists use to divide Earth's history into intervals?
changes in the fossil record
Select all of the answers that apply.
Which of the following are possible causes of mass extinctions that scientists have identified?
- climate changes
- asteroids hitting Earth
- widespread volcanic activity
Which of the following are examples of the effects of living things on the atmosphere and climate?
- the buildup of oxygen in the atmosphere
-changes in levels of carbon dioxide
