Most of the Earth's water is __________ water.

• fresh

• land

• salt

• frozen

Glaciers, rivers, ponds, and most lakes contain ____________.

• salt water

• fresh water

• frozen water

Water is present under the Earth's surface in underground streams, known as _______________.

• ground cover

• ground water

• well water

• spring water

Humans are part of the ecosystem and therefore impact it. Which of the following events in an ecosystem may produce a negative effect?

• Preventing deer from depleting food resources.

• Restoring a natural habitat.

• Wildlife rangers minimizing disturbances.

• A lumber company clearing a forest.

A highway is built through a forest. This will most likely have which of the following effects on the organisms in the area?

• Increase the number of bird species in the forest

• Raise the birth rate of the animals on the forest floor

• Eliminate all species of plants found in the forest

• Make it difficult for animals to move through the forest

Raccoons eat aquatic animals. If chemicals entered the lake with rain water and destroyed the plants, how would this impact the raccoon population?

• Raccoons would have less aquatic animals to eat.

• Raccoons would begin eating land plants.

• Raccoons would only drink water.

• Raccoons would have more aquatic animals to eat.

When the last member of a species dies, the species becomes

• extinct
• endangered
• threatened
• dead

In a pond ecosystem, what would happen to frogs if the insect population decreased?

• There would be more frogs in the pond

• There would be more insects in the pond

• There would be less frogs in the pond

• More fish would move to the pond

An example of a natural change to the ecosystem is:

• A highway built in the middle of the desert. 
• Lightening strikes and starts a fire in the forest. 
• A rancher placing too many grazers in a small area leading to overgrazing.

What would most likely happen if an ecosystem no longer received sunlight?

• The number of herbivores would increase
• The number of plants would increase
• all organisms would adapt
• All living organisms would eventually die