Ch. 17 Test

_____________________ are scientists who study fossils.

• Geologists

• Archeologists

• Paleontologists

The _____________________ provides evidence about the history of life on Earth.

• fossil record

• library

• internet

When a species is _____________, it is said to have died out.

• lost

• extinct

• vanished

In __________________, the age of a fossil is determined by comparing its placement with that of fossils in other layers of rock.

• radioactive dating

• index dating

• relative dating

Scientists also use ___________________ to compare the relative ages of fossils.

• radioactive dating

• index fossils

• relative dating

A ______________ is the length of time required for half of the radioactive atoms in a sample to decay.

• full-life

• quarter-life

• half-life

In ___________________, scientists calculate the age of a sample based on the amount of remaining radioactive isotopes it contains.

• radioactive dating

• index dating

• relative dating

Paleontologists use divisions of the _______________________ to represent evolutionary time.

• geologic map

• geologic time scale

• geologic graph

These are divided into the Paleozoic, Mesozoic, and Cenozoic.

• Eras

• Periods

• Epochs

The Triassic is an example of one of these.

• Era

• Period

• Epoch