Deck 37: Communities and Ecosystems

Question 1

Given that CO2 is produced by cellular respiration,why does the amount of CO2 in the atmosphere remain relatively constant? (When answering this question,exclude the impact of human activities on atmospheric CO2.)

A)CO2 mostly forms carbonate rocks.
B)CO2 is converted in photosynthesis to carbohydrates.
C)CO2 is split apart during photosynthesis.
D)CO2 is trapped in dead organisms' bodies.

Answer 1

B

Question 2

One of the most worrisome results of the large- scale clearing and cultivation of land is

A)erosion and soil degradation.
B)the inability fo supply enough food for growing populations.
C)hurricanes.
D)the inability to supply fresh water.

Answer 2

A

Question 3

Which of the following ecological problems might result from fertilizing a golf course with phosphorus- rich fertilizer?

A)accumulation of toxic levels of phosphorus in animals in the vicinity,especially those higher on the food chain
B)poisoning of the grass caused by excess phosphorus
C)a slowdown in the weathering of rock that releases phosphates into the soil under natural conditions
D)heavy growth of algae and cyanobacteria in lakes and rivers caused by phosphorus runoff

Answer 3

D

Question 4

In a certain ecosystem,field mice are preyed on by snakes and hawks.The entry of wild dogs into the system adds another predator of the mice.Of the following,the most likely short- term result of this addition is

A)a reduction in numbers of mice.
B)migration of the hawks to another ecosystem.
C)a tendency for hawks to prey on the dogs.
D)an increase in snake population.

Question 5

The sum total of a population's use of the biotic and abiotic resources of its habitat constitutes its

A)environment.
B)range.
C)evolution.
D)niche.

Question 6

Biological control is defined as

A)the exploitation of coevolutionary principles to produce pesticides.
B)an intentional attempt to increase the numbers of specific prey populations.
C)the intentional release of a natural enemy of a pest population.
D)the use of chemicals,such as pesticides,to control pests.

Question 7

You want to do all that you can to safeguard the environment by preserving energy.One simple thing that you can do is to eat a diet consisting only of organisms that are

A)secondary consumers.
B)producers.
C)a mix of producers and consumers.
D)primary consumers.

Question 8

One mechanism that prey populations evolve to avoid predation is

A)chemical defenses.
B)secretion of enzymes that break down toxic plant compounds.
C)secretion of digestive enzymes that hydrolyze glucose.
D)development of a short gestation period.

Question 9

About how much of the energy in the producers of an ecosystem will be available to secondary consumers in this ecosystem?

A)about 1%
B)about 50%
C)about 10%
D)100%

Question 10

When two different populations in a community benefit from their relationship with each other,the result is called

A)parasitism.
B)benefism.
C)competition.
D)mutualism.

Question 11

When a crocodile eats a fish,the interspecific interaction between the two could be expressed as for the crocodile and _ for the fish.

A)+ ...+
B)- ...-
C)+ ...-
D)- ...+

Question 12

One reason it is important to understand community ecology is

A)to provide an enriched habitat for humans.
B)to aid in conservation of endangered species.
C)for identification of stomach microbes.
D)to understand the life cycle of fish,such as cichlids.

Question 13

Which trophic level in this food chain represents the secondary consumer?

A)trophic level A
B)trophic level B
C)trophic level C
D)trophic level D

Question 14

In an average ecosystem,about how much energy is present in the organisms at a given trophic level compared to the organisms at the next higher trophic level?

A)half as much
B)ten times as much
C)twice as much
D)a tenth as much

Question 15

We expect that a keystone species that is a predator will

A)maintain the species diversity in a community.
B)harvest prey species down to extinction.
C)reduce the diversity of the community.
D)help many of its prey reproduce.

Question 16

Organisms that digest molecules in organic material and convert them into inorganic forms are

A)primary producers.
B)decomposers.
C)primary consumers.
D)detritivores.

Question 17

In a food chain consisting of phytoplankton -zooplankton -fish -fishermen,the fishermen are

A)quaternary consumers
B)secondary consumers.
C)tertiary consumers.
D)secondary producers.

Question 18

When a New England farm is abandoned,its formerly plowed fields first become weedy meadows,then shrubby areas,and finally forest.This sequence of plant communities is an example of

A)a trophic chain.
B)secondary succession.
C)primary succession
D)evolution.

Question 19

An owl and a hawk both eat mice.Which of these describes the relationship between a hawk and an owl?

A)competition
B)mutualism
C)predation
D)parasitism

Question 20

Which of the following is an example of predation?

A)the vivid colors of the poison- arrow frog in Costa Rica
B)a goldfinch feeding on the seeds of a thistle plant
C)a lizard's camouflage
D)a hawk swooping down quickly to capture,kill,and eat a prairie king snake

Question 21

Non- native species that are introduced in new environments,spread far beyond the original point of introduction,and cause damage are called

A)destructive species.
B)enemy species.
C)proprietary species.
D)invasive species.

Question 22

Camouflage typically evolves as a result of

A)interspecific competition.
B)herbivory.
C)mutualism.
D)predation.

Question 23

Denitrifying bacteria convert to .

A)nitrogen gas ...nitrites
B)nitrogen gas ...nitrates
C)ammonium ...nitrates
D)nitrates ...nitrogen gas

Question 24

Which arrow shows nitrogen fixation?

A)arrow A
B)arrow B
C)arrow C
D)arrow D

Question 25

During ecological succession,the species composition of a plant community generally

A)changes from a diverse community in which many plants are common to one in which a few species are numerically dominant.
B)remains stable as long as major environmental factors (climate,human interference)remain constant.
C)changes until forest is established and a single species remains.
D)changes gradually because each species responds differently to the changing environment.

Question 26

Eutrophication of a lake could occur if

A)fish were removed.
B)phosphate- rich detergents were dumped into the lake.
C)fertilizers were applied in an insoluble form.
D)runoff from overfertilized lawns was prevented from reaching the lake.

Question 27

Within an ecosystem,a tree is a

A)producer.
B)secondary consumer.
C)detritivore.
D)primary consumer.

Question 28

If an overlap develops between the ranges of two closely related species,and if the species occupy the same niche in the zone of overlap,what will probably happen in the zone of overlap?

A)Both species will coexist,provided the environment in the zone of overlap is different from that in either individual range.
B)Both species will coexist,provided the environment in the zone of overlap is similar to that of one of the individual ranges.
C)One species will take over most or all of the zone of overlap.
D)A new species will arise by hybridization.

Question 29

In an ecosystem,you would expect to find interspecific competition between

A)populations of two species that occupy the same niche.
B)two wasp species that mimic each other's appearance.
C)males and females of a species in which both sexes occupy the same niche.
D)a prey species and its predator.

Question 30

In addition to abiotic factors,community composition of plants can be severely compromised by

A)non- native birds.
B)introduction of chestnut trees.
C)parasites and pathogens.
D)rapid coevolution.

Question 31

Which of the following substances is cycled between organic matter and abiotic reservoirs?

A)fat
B)nucleic acid
C)protein
D)carbon

Question 32

Most plants have a variety of chemicals,spines,and thorns because the plants

A)are camouflaged into their surroundings.
B)feed on the organisms that try to eat them.
C)cannot run away from herbivores.
D)are relying upon Batesian mimicry.

Question 33

Carbon mainly cycles between the biotic and abiotic worlds through the processes of

A)cellular respiration and photosynthesis.
B)transpiration and photosynthesis.
C)evaporation and photosynthesis.
D)cellular respiration and transpiration.

Question 34

Which arrow shows CO2 released as a product of cellular respiration?

A)arrow A
B)arrow B
C)arrow C
D)arrow D

Question 35

Which of the following statements about the phosphorus cycle is true?

A)Plants release dissolved phosphorus ions in the soil.
B)Guano can be used by farmers to add phosphorus to the soil.
C)Phosphorus that drains from soils into the sea becomes part of new rock and will cycle back into living organisms.
D)Phosphorus has its main abiotic reservoir in water.

Question 36

Dinoflagellates are important to coral and coral- dwelling animals because they

A)are toxic to species that prey on reef- dwelling fish.
B)provide shelter for the fast- growing seaweeds associated with coral.
C)produce CO2 and nitrogen for coral.
D)produce energy that is used by coral animals through photosynthesis.

Question 37

Which of the following represents a step in the nitrogen cycle?

A)nitrogen- fixing bacteria convert atmospheric nitrogen to ammonium
B)nitrites bind to soil particles
C)nitrogen- fixing bacteria convert atmospheric nitrogen to nitrates
D)denitrifiers convert ammonium to atmospheric nitrogen

Question 38

Some herbivore- plant interactions evolved through a series of reciprocal evolutionary adaptations in both species.The process is called

A)selection.
B)trophism.
C)herbivory.
D)coevolution.

Question 39

In a hypothetical food chain consisting of grass,grasshoppers,sparrows,and hawks,the grasshoppers are

A)secondary producers.
B)secondary consumers.
C)primary consumers.
D)primary producers.

Question 40

For a given area and time period,the amount of solar energy converted to chemical energy in organic compounds is called

A)primary production.
B)secondary succession.
C)primary succession.
D)secondary production.

Question 41

Which of the following statements regarding food webs is true?

A)Nutrient transfer moves from producer to consumer and back.
B)Detritivores consume dead organic matter from a specific trophic level.
C)A consumer eats only one type of producer.
D)Several species of primary consumers may feed on the same species of producer.

Question 42

Which of the following processes does not occur in ecosystems?

A)Carbon is cycled between biotic and abiotic forms.
B)Energy flows through the system.
C)Producers convert light energy to chemical energy.
D)The energy source that powers the system is used by consumers to make organic compounds.

Question 43

A community is composed of

A)potentially interacting populations of different kinds of organisms.
B)one species of organism living in a specific environment on Earth.
C)the factors that constitute an organism's niche.
D)living organisms and their nonliving environment.

Question 44

The number of species in a community is called the

A)species richness.
B)species diversity.
C)species index.
D)species population.

Question 45

A biology teacher takes fish,algae,pond weed,invertebrates,and bottom muck from a local pond and establishes them in an aquarium.When the system is stable,the teacher seals it into a large,airtight glass box and leaves the box in a sunny location.After three months,the organisms in the aquarium appear alive and healthy.Which of the following statements about the experiment is true?

A)The air in the glass box contains no carbon dioxide.
B)Some of the energy in the system has moved from one organism to another during the three months.
C)No energy has entered or left the glass box during the three months.
D)During the three months,the biomass of animal life was greater than the biomass of plant life.

Question 46

A hypothetical community on a barren mid- Atlantic island consists of two fish- eating seabirds (the booby and the noddy),the fungi and microorganisms that live on the birds' dung,a tick that feeds on these two birds,a cactus,a moth that feeds on cast- off feathers,a beetle that lives on dung organisms,and spiders that eat the other arthropods.There are no other plants and no lichens.Which of the following choices incorrectly pairs a member of this assemblage with its position in the trophic structure?

A)booby,primary consumer
B)cactus,producer
C)moth,detritivore
D)fungi,detritivores

Question 47

Which of the following statements about the nitrogen cycle is true?

A)When plants and animals die,nitrogen is removed from the nitrogen cycle.
B)Nitrogen cannot be cycled through living organisms.
C)Nitrogen gas is converted to nitrates in plant leaves.
D)The nitrogen cycle requires different types of bacteria.

Question 48

On Earth,most organic molecules are produced by

A)photosynthesis.
B)cellular respiration.
C)glycolysis.
D)hydrolysis.

Question 49

The prokaryotes that cause tooth decay have a _ relationship with humans.

A)parasitic
B)competitive
C)mutualistic
D)predatory

Question 50

The flow of into ecosystems occurs in one direction only,while are recycled within the ecosystem itself.

A)organic compounds ...minerals
B)genetic information ...genotypes
C)minerals ...energy compounds
D)energy ...chemicals