Biology 2015

Sylvia S. Mader, Michael Windelspecht

Chapter 45

Community and Ecosystem Ecology

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Chapter Questions

Problem 1

The species composition of a community is called
a. species richness.
b. species diversity.
c. climax community.
d. pioneer species.
e. ecological niche

Angela U.

Angela U.

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Problem 2

The ecological niche of an organism
a. is the same as its habitat.
b. includes how it competes for and acquires food.
c. is specific to the organism.
d. is usually occupied by another species.
e. Both b and c are correct.

Bryan L.

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Problem 3

What type of interaction is it when an alfalfa plant gains fixed nitrogen from the bacterial species Rhizobium in its root system and the Rhizobium gains carbohydrates from the plant?
a. mutualism
b. parasitism
c. commensalism
d. competition
e. predation

Sumana R.

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Problem 4

What type of interaction is it when both foxes and coyotes in an area feed primarily on a limited supply of rabbits?
a. mutualism
b. parasitism
c. commensalism
d. competition
e. predation

Bryan L.

Numerade Educator

Problem 5

Which is the correct sequence of events during primary succession?
a. low shrub–high shrub–grass–shrub-tree–low tree–high tree
b. high shrub–low shrub–grass–low tree–high tree–shrub-tree
c. grass–shrub-tree–high tree–low tree–low shrub–high shrub
d. grass–low shrub–low tree–shrub-tree–high shrub–high tree
e. grass–low shrub–high shrub–shrub-tree–low tree–high tree

RM

Rand M.

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Problem 6

Mosses growing on bare rock will eventually help create soil. These mosses are involved in _______ succession.
a. primary
b. secondary
c. tertiary
d. complete
e. incomplete

Bryan L.

Numerade Educator

Problem 7

In what way are decomposers like producers?
a. Either may be the first member of a grazing or a detrital food chain.
b. Both produce oxygen for other forms of life.
c. Both require nutrient molecules and energy.
d. Both are present only on land.
e. Both produce organic nutrients for other members of ecosystems.

Bryan L.

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Problem 8

When a heterotroph takes in food, only a small percentage of the energy in that food is used for growth, because
a. some food is not digested and is eliminated as feces.
b. some metabolites are excreted as urine.
c. some energy is given off as heat.
d. All of these are correct.
e. None of these are correct

Bryan L.

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Problem 9

During chemical cycling, inorganic nutrients are typically returned to the soil by
a. autotrophs.
b. detritivores.
c. decomposers.
d. tertiary consumers.

Jade S.

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Problem 10

How do plants contribute to the carbon cycle?
a. When plants respire, they release CO2 into the atmosphere.
b. When plants photosynthesize, they consume CO2 from the atmosphere.
c. When plants photosynthesize, they provide oxygen to heterotrophs.
d. Both a and b are correct

Bryan L.

Numerade Educator

Problem 11

Choose the statement that is true concerning this food chain:
grass $\rightarrow$ rabbits $\rightarrow$ snakes $\rightarrow$ hawks
a. Each predator population has a greater biomass than its prey population.
b. Each prey population has a greater biomass than its predator population.
c. Each population is omnivorous.
d. Each population returns inorganic nutrients and energy to the producer.
e. Both a and c are correct.
f . Both a and b are correct.

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Problem 12

Label this diagram of an ecosystem:

Bryan L.

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