Unit 4 Checkpoint A/B

Front

How old is the Earth?

Back

The Earth is approximately 4.6 billion years old.

Front

What is catastrophism?

Back

Catastrophism is the theory that the Earth has been shaped by sudden, violent events such as natural disasters.

Front

In which era did early horses first appear?

Back

Early horses first appeared in the Cenozoic era.

Front

What marks the end of one geologic era and the beginning of another?

Back

A mass extinction event marks the end of one geologic era and the beginning of another.

Front

How many millions of years ago did dinosaurs first appear?

Back

Dinosaurs first appeared approximately 248 million years ago.

Front

What is the significance of the Cenozoic era?

Back

The Cenozoic era is significant for the evolution of mammals and birds, and the appearance of early horses.

Front

Define geologic time scale.

Back

The geologic time scale is a system of chronological dating that relates geological strata to time.

Front

What is the difference between gradualism and catastrophism?

Back

Gradualism is the theory that changes in the Earth occur slowly over time, while catastrophism suggests that changes occur suddenly due to catastrophic events.

Front

What is a mass extinction?

Back

A mass extinction is a widespread and rapid decrease in the biodiversity on Earth, often leading to the extinction of many species.

Front

What are the three main eras of the geologic time scale?

Back

The three main eras are Paleozoic, Mesozoic, and Cenozoic.