Question

Use the drop-down menus and what you know about index fossils to choose the correct answers.

Index fossils are the remains of organisms that lived on Earth for
periods.

First, geologists use relative age to determine the
of the layers of rock.

They then use index fossils to relate the layers to those in
locations.

Answer 1

Index fossils are the remains of organisms that lived on Earth for **short** periods.

First, geologists use relative age to determine the **age** of the layers of rock.

They then use index fossils to relate the layers to those in **different** locations.