Exam 21: Ecosystems

Energy does not cycle through an ecosystem.This is because energy enters an ecosystem through photosynthesis as it changes to chemical energy.This is then used to fuel metabolic activities in

Explain why only roughly 10 percent of the energy available in one trophic level is available in the next higher trophic level.

A community of organisms together with the physical environment in which they live is known as a(n)

Compare and contrast grassy marsh wetlands to bogs and explain why one of these freshwater biomes is more productive than the other.

In the absence of ________,nutrient recycling within the ecosystem would completely stop.

A grassland ecosystem has 400,000 kcal of energy stored in the primary producer level.Grasshoppers eat the grass,meadowlarks eat the grasshoppers,and a hawk eats the meadowlarks.How many kcals are now stored,and available,in the hawk?

If there are 20,000 kcal available in the primary producer level of an ecosystem,how many kcal would be available in the secondary consumer level?

Tuna are predatory fish that consume smaller,carnivorous fish that have fed on zooplankton.The zooplankton had fed on phytoplankton.When a person eats tuna,he or she is consuming the ________ trophic level of the food chain.

What best explains the following observation: consumers directly use approximately 20 percent of a forest's net primary productivity (NPP),whereas decomposers directly use approximately 80 percent?

The shallowest but most productive of the aquatic biomes are ________.These tidal ecosystems exist where rivers flow into the ocean.

The units used in the infographic below report total energy available from primary producers in indicated biomes in ________.

Explain the difference in net primary productivity (NPP)between temperate grasslands and tropical grasslands.Include data units.

Rabbits,foxes,tapeworms,and fungi are all examples of

In marine ecosystems,net primary productivity tends to be

Each level of an energy pyramid corresponds to a step in a food chain and is called a(n)________ level.

All of the living organisms present in an ecosystem comprise the ________ or biotic portion of the ecosystem.

Match each term to its correct description below. -This biome is dominated by dense growths of drought-resistant plants that thrive through the alternating cool,rainy winters and hot,dry summers.The vegetation includes scrub oak,pine,mountain mahogany,and manzanita.It is inhabited by jackrabbits,gophers,lizards,and snakes.

Using the food chain shown below,explain how many calories are available in the consumer trophic levels and why.

Ecologists often define an ecosystem with regard to how BOTH ________ are acquired and distributed by the biotic community.

Why don't ecosystems always have sharply defined physical boundaries?