MP4 6 wks review

When comparing two ecosystems of the same type, the ecosystem that supports a greater number of species is _______ than the ecosystem that supports only a few.

• more fertile

• less habitable

• more sustainable

• less biodiverse

Which of the following increases the sustainability of an ecosystem?

• decreased internal stimuli

• increased external stimuli

• increased biodiversity

• decreased heredity

A grassland ecosystem (ecosystem X) supports 13 different grass species. A different grassland ecosystem (ecosystem Y) supports just one species of grass. Bison graze on all of the grass species in both of these ecosystems.

A drought strikes both ecosystem X and ecosystem Y, but the bison in ecosystem X are better able to survive it. Which of the following is a likely explanation?

• The bison in ecosystem X only eat one species of grass.

• Ecosystem Y has a greater amount of biodiversity.

• Ecosystem Y has a greater amount of biomass.

• Ecosystem X has a greater amount of biodiversity.

The images show food webs for two similar ecosystems.

Which ecosystem is more likely to survive if a disease causes a significant decline in the insect population?

• ecosystem 1, because more types of plants are available for insects to eat

• ecosystem 2, because fewer animals will need to adapt to the new conditions

• ecosystem 2, because there are fewer animals competing for resources

• ecosystem 1, because animals that eat insects have more sources of food

A species of wasp dies out in a prairie ecosystem. This species used to perform the important task of pollinating a widespread plant species.

This ecosystem will be less damaged by this local extinction if...

• there are other insect species that also pollinate the plant.

• the plant species also dies out.

• most of the large animal species depend on the plant for food.

• the wasp species is still successful in other ecosystems.

An ecosystem that offers many different niches...

• can support many different species.

• usually only supports insect life.

• supports animal life but not plant life.

• cannot support very many species at once.

If many different species live in an ecosystem, this helps the ecosystem to fill its _______.

• populations

• producers

• communities

• niches

Plants and animals in the tundra must be able to adapt to the extremely ___________ weather

• small

• cold

• perennials

• shallow

Very little sun reaches this part of the rainforest.

• equal
• earth
• floor
• carnivorous 

Which two biomes have the least precipitation?

• tropical rain forest and temperate grasslan
• savanna and tropical dry forest
• tundra and desert
• boreal forest and temperate woodland