Module D U1 L2 The History of Life on Earth

What is the definition of extinction?

• The birth of a new species

• The death of every member of a species

• The migration of species

• The adaptation of species

What type of organisms were the earliest evidence of life on Earth?

• Multi-celled organisms

• Single-celled organisms

• Dinosaurs

• Plants

What significant event is referred to as the Cambrian explosion?

• The formation of the Earth

• The extinction of dinosaurs

• The appearance of mammals

• A large increase in the variety of fossils

What is a transitional fossil?

• A fossil that has body structures of both ancestral and descendant species

• A fossil that is found only in one layer of rock

• A fossil that is completely intact

• A fossil that shows no change over time

What does the fossil record show about species over time?

• Species only exist in the present

• Species never change

• Species appear and disappear over time

• Species always increase in number

What is the earliest fossilized cells scientists have found?

• 3.8 billion years old

• 1 billion years old

• 3.5 billion years old

• 2.5 billion years old

What type of carbon do living organisms use?

• Carbon-15

• Carbon-12

• Carbon-14

• Carbon-13

What is a mass extinction?

• When a single species dies out

• When species migrate to new areas

• When many species die out at the same time

• When new species are formed

What can scientists analyze to find the cause of mass extinctions?

• Weather patterns

• Rock layers before, during, and after an extinction event

• Modern animal behavior

• Fossilized plants only

What does a rock layer with very few fossils suggest?

• A volcanic eruption

• A recent formation

• Poor conditions for life

• High biodiversity