Study Guide UNIT 2

Are you ok that these are my answers that i found?

• Yes

• No

How old do scientists say the earth is?

• 1 million years

• 10,000 years

• 100 billion years

• 4.6 billion years

What are some ways that organisms become fossils?

• trace fossils

• petrification

• dying

• deposition

What are some examples of trace fossils?

• Footprints, burrows, and coprolites
• Feather fossils, scale fossils, and hair fossils
• Rock fossils, mineral fossils, and bone fossils
• Shell fossils, plant fossils, and insect fossils

What is a trace fossil?

Answer explanation

a structure or part of an organism that was left behind

What are the laws of science that help you put rock layers in order?

• Law of Cross-Cutting Relationships

• Law of Uniformitarianism
• Law of Catastrophism

• Law of Superposition

In sedimentary rocks, which layers are the oldest and youngest?

Answer explanation

the layers in top are younger, and the layers on top are older. If rock cuts through, the rock that cuts through is younger

Describe how scientists would use a fossil to figure out how old a rock is.

Answer explanation

They see how deep it is and they figure the age out by using radiometric dating on their fossil sample.

What do scientists study to figure out how old the Earth is? (Where do they get the rocks that they study?)

• Volcanic ash
• Meteorites

• Water samples
• Rocks

What are examples of BOTH slow and fast change on Earth?