Chapter 6 Life Science

Organisms began living on Earth ______ years ago.

• 3.8 billion

• 4.6 billion

• 1.2 billion

• 64 million

What type of organisms evolved 1.2 billion years ago?

• multicellular

• unicellular

• dinosaurs

• bacteria

Some of the first organisms to live on land were ______.

• bacteria

• reptiles

• amphibians

• insects

Comparing a fossil to other fossils found in different rock layers is called _______________.

• relative age dating

• absolute age dating

• specialized age dating

• radioactive age dating

After a mass extinction, __________________________.

• huge numbers of new species die out at once.

• huge numbers of new species stop evolving.

• decreasing numbers of new species develop.

• increasing numbers of new species develop.

The earliest living things lived ___________.

• on land

• in the ocean

• in freshwater lakes

• in the air

What were the first mutli-cellular organisms?

• `seaweeds

• insects

• fish

• dinosaurs

How do scientists determine the absolute age of a fossil?

• determining where it was found

• measuring its radioactivity

• looking at its size and shape

• identifying what type of rock it is found in

No two tigers have the same stripes. This is an example of _____________________.

• variation

• adaptation

• evolution

• a vestigial organ

Darwin's theory of natural selection is based on 4 key principles. Which is not one of the principles?

• adaptation

• overproduction

• variation

• fossil record