Chapter 26: Ecosystem

About what percentage of water on Earth's surface contains high concentrations of salt?

• 15%

• 35%

• 65%

• 95%

The region below about 200m in an open ocean is called the ____________.

• canopy

• dark zone

• understory

• steppes

Answer explanation

The dark zone of the ocean is a unique ecosystem because little sunlight penetrates this depth.

Which of these biomes receives the least amount of rainfall every year?

• desert

• taiga

• tropical rain forest

• temperate deciduous forest

Answer explanation

Desert regions usually receive less than 25 cm of rain in a year.

Which one of these is true of the tropical rain forest biome?

• The soil thaws during the summer.

• The soil contains little dead vegetation.

• The soil is thin and gravelly.

• The soil contains permafrost.

Answer explanation

In the tropical rain forest, dead leaves and vegetation is quickly eaten by organisms that live there. The soil gets little of this vegetation added to its composition.

The gradual changes that happen in the types of species living in a region are called _________________.

• balance

• permafrost

• community

• sucession

Answer explanation

Primary succesion and secondary succesion are parts of ecological change.

Which of these biomes receives little annual precipitation?

• temperate deciduous forest

• tundra

• taiga

• grasslands

Answer explanation

Tundra biomes typically receive less than 25 cm of precipitation every year.

_____________ are usually shallow and filled with an abundance of plant and animal life.

• Lakes

• Oceans

• Ponds

• Rivers

Which of the following animals can be found in a wetlands environment?

• bear

• salamander

• lemming

• beaver

Answer explanation

Beavers, muskrats, and migratory birds are all animals that may be found in a wetlands.

When is intertidal zone covered with water?

• at low tide

• at high tide

• during daylight hours

• during nightime hours

Answer explanation

The intertidal zone is covered with water at high tide and exposed to the air and direct sunlight at low tide.

Which biome typically has four distinct seasons?

• temperate rain forest

• temperate deciduous forest

• tundra

• desert