Geologic Time

The Earth is ___billion years old.

Tags

NGSS.MS-ESS1-4

The first life began on Earth ___ billion years ago.

The beginning of the ____________________ period is considered an important step in the history of our planet because it is marked by an abrupt emergence of complex life-forms.

• Cambrian

• Triassic

• Tertiary

• Mesozoic

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

A species is _________when all of its members have died.

Tags

NGSS.MS-LS4-1

_____________________________ occur when many species go extinct within a short time.

• mass extinction

• volcanic eruption

• cyanobacteria

• geologic timescale

Tags

NGSS.MS-LS4-1

The ______________ explosion refers to the change in life during the Cambrian period which multicellular organisms rapidly evolved to produce millions of new forms of complex life.

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

Scientists believe that _______________________________ were responsible for adding oxygen to the Earth’s early atmosphere.

• cyanobacteria

• plants

• bacteria

• dinosaurs

The model that scientists use to show Earth’s history is called the ___________________________________.

• geologic timescale

• Eras

• Paleozoic

• mass extinction

Tags

NGSS.MS-ESS1-4

An _________________________ impact is thought to have killed the dinosaurs.

• asteroid

• volcanic

• earthquake

• oxygen

Which has caused mass extinctions in Earth's past? Choose all that apply.

• volcanic eruptions

• changes in temperature

• asteroid impacts

• nuclear bombs

Tags

NGSS.MS-LS4-1