Earth's Systems and Their Functions

What makes Earth unique among known planets?

• It is the largest planet.

• It has a strong magnetic field.

• It is the only planet known to have life.

• It has a thick atmosphere.

How many major systems does Earth have that interact to make life possible?

• Three

• Four

• Five

• Six

What is the atmosphere?

• The solid land and rocks of Earth.

• All the water on Earth.

• The air that surrounds Earth.

• All living organisms on Earth.

How does Earth's atmosphere protect us from meteoroids?

• It pulls them into orbit around Earth.

• It causes them to burn up as meteors.

• It deflects them away from Earth.

• It absorbs them into its layers.

What is the biosphere?

• The layer of gases surrounding Earth.

• All the water on Earth.

• The solid part of Earth's surface.

• All living organisms on Earth.

Which of the following is considered part of the biosphere?

• A recently fallen leaf that has not yet decomposed.

• A rock on a mountain.

• A cloud in the sky.

• Ice in a glacier.

What does the geosphere include?

• Only mountains and hills.

• All the water on Earth.

• The land and rocks, including ocean floors.

• All living things on land.

What percentage of Earth's water is saltwater found in the oceans?

• 3%

• 25%

• 50%

• 97%

Where is most of Earth's freshwater stored?

• In rivers and lakes.

• In underground sources.

• In glaciers.

• In clouds.

What is the primary function of the magnetosphere?

• To regulate Earth's temperature.

• To provide oxygen for living things.

• To protect Earth from harmful solar particles.

• To create weather patterns.