Unit 7 Review

An ecosystem is generally healthy if—

• wildfires do not occur.

• its soil includes a variety of rock types.

• it rains a lot.

• its species diversity is relatively high.

An abundant, ground-dwelling, sun-loving plant species becomes a rare find within 20 years. Why might that be?

• It transformed into a completely new species.

• It could no longer take the heat.

• Plant hunters harvested all of them.

• Other plants, such as shrubs and trees, may be blocking most sunlight.

A relatively stable state of succession, or the end product of succession

• Biome

• Ecosystem

• Climax Community

• Biodiversity

A homeowner cuts down all of the trees on his lot, except for his favorite tree, the birch. What might happen?

• He will have more open views.

• Fewer insects will live on his lot.

• Fewer bird species will live on his lot.

• All of these

Capable of maintaining the current community at a steady level without exhausting natural resources or causing severe ecological damage

• Sustainable

• Ecosystem

• Habitat

• Climax Community

A change in types of species present in a community over time such as after a disturbance

• Biodiversity

• Succession

• Ecosystem

• Climax community

In the process of ecological succession, grasses appear before shrubs because grasses -

• loosen the dirt for new trees to take root.

• provide food for animals returning to the area.

• can grow rapidly even in areas with shallow soil.

• require plenty of sunlight to make their own food.

Which of the following is an example of one stage in ecological succession?

• Weeds grow in a garden.

• Fish swim in a pond.

• A bird lays eggs in a nest.

• A tree falls over in a forest.

After a catastrophic wildfire that clears the land of all plants and trees, -

• only trees will grow in the burned area.

• weeds will grow in the area before trees grow.

• plants will not grow again in the burned area.

• bushes will grow in the area before weeds grow.

The greatest sustainability is expected in the habitat with the -

• most biodiversity.

• highest latitude.

• largest water supply.

• greatest biomass.