Bio 53

A community's actual evapotranspiration is a reflection of A) solar radiation, temperature, and water availability. B) the number of plants and how much moisture they lose. C) the depth of the water table. D) energy availability. E) plant biomass and plant water content.

A

According to the equilibrium model of island biogeography, all of the following contribute to greater species diversity on an island except A) a relatively recent formation of the island. B) a shorter distance of the island from the mainland. C) a bigger island. D) a lower extinction rate on the island. E) higher rates of migration to and from the island.

A

Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction? A) mutualism B) commensalism C) parasitism D) competition E) predation

A

The presence of all of the following tend to increase species diversity except A) competitive exclusion. B) keystone predators. C) patchy environments. D) moderate disturbances. E) migration of populations.

A

Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation? A) competitive exclusion B) predation of Chthamalus by Balanus C) cooperative displacement D) primary succession E) mutualism

A

Which of the following is an example of Müllerian mimicry? A) two species of unpalatable butterfly that have the same color pattern B) a day-flying hawkmoth that looks like a wasp C) a katydid whose wings look like a dead leaf D) two species of rattlesnake that both rattle their tails E) two species of moths that with wing spots that look like owl's eyes

A

Which of the following is an example of aposematic coloration? A) stripes of a skunk B) eye color in humans C) green color of a plant D) colors of an insect-pollinated flower E) a katydid whose wings look like a dead leaf

A

Which of the following is considered by ecologists a measure of the ability of a community either to resist change or to recover to its original state after change? A) stability B) succession C) partitioning D) productivity E) competitive exclusion

A

0) The species richness of a community refers to the A) number of food chains. B) number of different species. C) energy content of all species. D) relative numbers of individuals in each species. E) total number of all organisms.

B

A species of fish is found to require a certain water temperature, a particular oxygen content of the water, a particular depth, and a rocky substrate on the bottom to thrive. These requirements are part of its A) dimensional profile. B) ecological niche. C) prime habitat. D) resource partition. E) home base.

B

According to the competitive exclusion principle, two species cannot continue to occupy the same A) habitat. B) niche. C) territory. D) range. E) biome

B

All of the following describe possible results of competition between two species except A) competitive exclusion. B) aposematic coloration. C) resource partitioning. D) reduction in the population of one species. E) reduction in the populations of both species.

B

As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. Where their ranges overlap, however, the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory, their offspring behave in the same manner. You have discovered an example of A) mutualism. B) character displacement. C) Batesian mimicry. D) facultative commensalism. E) none of the above

B

Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees? A) mutualism B) parasitism C) commensalism D) facilitation E) competition

B

In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n) A) community facilitator. B) keystone species. C) herbivore. D) resource partitioner. E) mutualistic organism.

B

Resource partitioning is best described by which of the following statements? A) Competitive exclusion results in the success of the superior species. B) Slight variations in niche allow similar species to coexist. C) Two species can coevolve and share the same niche. D) Species diversity is maintained by switching between prey species. E) A climax community is reached when no new niches are available.

B

Resource partitioning would be most likely to occur between A) sympatric populations of a predator and its prey. B) sympatric populations of species with similar ecological niches. C) sympatric populations of a flowering plant and its specialized insect pollinator. D) allopatric populations of the same animal species. E) allopatric populations of species with similar ecological niches.

B

Species richness increases A) as one travels north from the equator. B) as one travels north from the South Pole. C) on islands as distance from the mainland increases. D) as rates of evapotranspiration decrease. E) as a community size decreases

B

The energetic hypothesis and dynamic stability hypothesis are explanations to account for A) plant defenses against herbivores. B) the length of food chains. C) the evolution of mutualism. D) resource partitioning. E) the competitive exclusion principle.

B

The oak tree pathogen Phytophthora ramorum migrated 650 km in ten years. West Nile virus spread from New York to 46 others states in five years. The difference in the rate of spread is probably related to A) how lethal each pathogen is. B) the mobility of their hosts. C) the fact that viruses are very small. D) innate resistance. E) none of the above

B

The rivet model of community structure suggests that A) damaged communities can be repaired if species are added. B) communities are tightly integrated units that may be seriously affected by changes in the abundance of only one species. C) most communities are robust in the face of disturbance. D) top-down regulation of communities is most important. E) if one species disappears, another will probably take its place.

B

To measure species diversity in a community, you need to know A) the number of species. B) the relative abundance of each species. C) the physical size of each species. D) both A and B E) A, B, and C

B

Which of the following interactions can correctly be labeled coevolution? A) the tendency of coyotes to respond to human habitat encroachment by including pet dogs and cats in their diets B) a genetic change in a virus that allows it to exploit a new host, which responds to virus-imposed selection by changing its genetically controlled habitat preferences C) a genetic change in foxes that allows them to tolerate human presence (and food) D) the adaptation of cockroaches to human habitation E) the ability of rats to survive in a variety of novel environments

B

Which of the following is not an example of a plant defense against herbivory? A) nicotine B) cryptic coloration C) spines D) thorns E) strychnine

B

Which of the following members of a marine food chain is most analogous to a grasshopper in a terrestrial food chain? A) phytoplankton B) zooplankton C) detritivore D) fish E) shark

B

Which of the following statements about the biogeographical aspects of diversity is not correct? A) The patterns of continental drift are important considerations in the study of the past and present distributions of species. B) The magnitude of photosynthesis is the factor that accounts for the major variations in species diversity over large areas of Earth. C) Species richness on an island reaches an equilibrium point when immigration equals extinction. D) A species may be limited to a particular range because it never dispersed beyond that range, or it dispersed but failed to survive in other locations. E) Island equilibrium theory applies to the relatively short period of time when colonization is the important process determining species composition; over a longer time, actual speciation affects the composition.

B

Which of the following terms best describes the interaction between termites and the protozoans that feed in their gut? A) commensalism B) mutualism C) competitive exclusion D) ectoparasitism E) endoparasitism

B

All of the following are terms that ecologists use to describe communities except for A) species richness. B) species diversity. C) Batesian diversity. D) trophic structure. E) stability.

C

An insect that has evolved to resemble a plant twig will probably be able to avoid A) parasitism. B) symbiosis. C) predation. D) competition. E) commensalism.

C

Elephants are not the most common species in African grasslands. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Elephants can be defined as what type of species in this community? A) redundant B) dominant C) keystone D) dominant and keystone E) none of the above

C

If you wanted to alter the structure of a bottom-up community, your best bet would be to A) remove the top predators. B) remove the trees and shrubs. C) add plenty of fertilizer. D) add more predators. E) reduce the number of primary producers.

C

When lichens grow on bare rock, they may eventually accumulate enough organic material around them to supply the foothold for later rooted vegetation. These early pioneering lichens can be said to do what to the later arrivals? A) tolerate B) inhibit C) facilitate D) exclude E) concentrate

C

Which of the following is an example of Batesian mimicry? A) an insect that resembles a twig B) a butterfly that resembles a leaf C) a nonvenomous snake that looks like a venomous snake D) a fawn with fur coloring that camouflages it in the forest environment E) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish

C

Which of the following statements about community interactions is not correct? A) Closely related species may be able to coexist if there is at least one significant difference in their niches. B) Plants can defend themselves against herbivores by the production of compounds that are irritating or toxic. C) Keystone predators reduce diversity in a community by holding down or wiping out prey populations. D) Mutualism is an important biotic interaction that occurs in communities. E) Some predators use mimicry to attract prey.

C

Which of the following statements about succession is correct? A) Secondary succession occurs where no soil exists. B) Primary succession occurs in areas where soil remains after a disturbance. C) Secondary succession can occur where a disturbance has left soil intact. D) Some cases of succession involve facilitation, a phenomenon in which local species inhibit the growth of newcomers. E) Through successional dynamics, most communities will eventually become more stable through time.

C

Which of the following statements is most consistent with F.E. Clements' integrated hypothesis? A) Species are distributed independently of other species. B) Communities lack discrete geographic boundaries. C) The community functions as an interactive unit. D) The composition of plant species seems to change on a continuum. E) The community is a chance assemblage of species.

C

Which of the following types of species interaction is incorrectly paired to its effects on the density of the two interacting populations? A) predation-one increases, one decreases B) parasitism-one increases, one decreases C) commensalism-both increase D) mutualism-both increase E) competition-both decrease

C

With a few exceptions, most of the food chains studied by ecologists have a maximum of how many links? A) 2 B) 3 C) 5 D) 10 E) 15

C

A biologist measures predation rates by crab spiders on flower-visiting insects in a particular field community. Then the biologist experimentally removes as many of the spiders as she can. She discovers that predation rates remain the same but that the major predators shift from spiders to ambush bugs. Which of the following community structure models is most consistent with her findings? A) individualistic B) integrated C) rivet D) redundancy E) manipulative

D

All of the following represent ways that animals defend themselves against predators except A) incorporating plant toxins into their tissues. B) cryptic coloration. C) mobbing. D) interspecific competition. E) hiding or fleeing.

D

Batesian mimicry systems involve all of the following except A) the models being noxious or disagreeable. B) the mimics having no defense mechanism. C) the ability of predators to "learn" characteristics of their prey. D) the models being cryptically colored. E) the models being easily recognized.

D

Communities can be linked by which of the following? I. predation II. systematics III. competition A) I only B) III only C) I and II only D) I and III only E) I, II, and III

D

Disturbances to ecological communities A) are frequently related to human activities. B) can remove organisms and alter resource availability. C) can create vacated ecological niches that other species can colonize. D) All of the above are true. E) Only A and B are true

D

Following clear-cutting of a broadleaf forest several hundred years ago, the land was colonized by herbaceous species that were replaced largely over time by shrubs, then by forest trees. Assuming the growth of the shrubs and trees was enhanced by the soil-holding properties of the herbaceous plants, which of the following processes best describe the progression from herbaceous plants to forest trees? A) primary succession; facilitation B) primary succession; inhibition C) primary succession; toleration D) secondary succession; facilitation E) secondary succession; inhibition

D

In a particular case of secondary succession, three species of wild grass all invaded a field. By the second season, a single species dominated the field. A possible factor in this secondary succession was A) equilibrium. B) facilitation. C) immigration. D) inhibition. E) mutualism.

D

In conservation biology, species-area curves for key taxa make it possible to predict A) the size of an area that needs to be sampled. B) the area that a keystone species will occupy. C) whether or not a redundancy model will apply to a given area. D) how the loss of a certain habitat area is likely to affect biodiversity. E) whether or not an area will reach equilibrium.

D

The dominant species in a community is A) characterized by very large individuals with long lives. B) the best competitor in the community. C) the best predator in the community. D) the population with the most biomass. E) the most energetically efficient species in the community.

D

The entire box shown in Figure 53.1 represents the niche of species A. Species A is biologically constrained from the striped area of its niche by species B. This is an example of A) dynamic stability. B) facilitation. C) commensalism. D) competitive exclusion. E) secondary succession.

D

There are more species in tropical areas than in places farther from the equator. .This is probably a result of A) fewer predators. B) a longer growing season. C) fewer major disturbances. D) B and C only E) all of the above as community size decreases.

D

Two species of insects from different geographic areas display characteristic black and red stripes. Which of the following is unlikely to be related to this phenomenon? A) aposematic coloration B) convergent evolution C) common ancestry D) mimicry E) d Which of the following is least likely to kill the organism it feeds on? A) herbivore B) predator C) seed eater D) carnivore E) parasite efense against a predator

D

Which of the following statements about the Yellowstone National Park fires of 1988 is false? A) Secondary succession followed the fires. B) The dominant lodgepole pines required fire to complete their normal life history. C) Human environmental policy increased the severity of the fires. D) It took years before new vegetation returned to the area. E) Severe drought helped to trigger the fires.

D

Which of the following statements is consistent with the competitive exclusion principle? A) Bird species generally do not compete for nesting sites. B) The density of one competing species will have a positive impact on the population growth of the other competing species. C) Two species with the same fundamental niche will exclude other competing species. D) Even a slight reproductive advantage will eventually lead to the elimination of inferior species. E) Evolution tends to increase competition between related species.

D

Which of the following traits does not characterize an individualistic community? A) discrete geographic boundaries B) strong abiotic influences on species distributions C) community composition changes along a gradient D) strong biotic influences on species distribution E) bottom-up organization

D

You are most likely to observe primary succession when you visit a(n) A) tropical rain forest. B) abandoned field. C) old riverbed. D) fairly recent volcanic island. E) deep sea vent

D

According to the nonequilibrium model, A) communities will remain in a state of equilibrium in the absence of human activities. B) community structure remains constant in the absence of interspecific competition. C) communities are assemblages of closely linked species that function as tightly integrated units. D) interspecific interactions induce changes in community composition over time. E) communities are constantly changing because of disturbances.

E

Consider a field plot containing 200 kg of plant material. Approximately how many kg of carnivore production can be supported? A) 200 B) 100 C) 20 D) 10 E) 2

E

Prairie dogs once covered the expanses of the Great Plains. Their grazing made the grass more nutritious for the huge herds of bison, and a variety of snakes, raptors, and mammals preyed on the rodents. In fact, the black-footed ferret (now endangered) specialized in prairie dog predation. Today, growing neighborhoods have covered many prairie dog towns. Which of the following statements about prairie dogs is not true? A) Their realized niche has diminished. B) They are commensals with bison. C) They are reasonably considered a keystone species. D) Their fundamental niche remains unaltered. E) Their fundamental niche has diminished.

E

The sum total of an organism's interaction with the biotic and abiotic resources of its environment is called its A) habitat. B) logistic growth. C) biotic potential. D) microclimax. E) ecological niche.

E

Which of the following is an example of cryptic coloration? A) bands on a coral snake B) brown color of tree bark C) markings of a viceroy butterfly D) colors of an insect-pollinated flower E) a "walking stick" insect that resembles a twig

E

Which of the following is least likely to kill the organism it feeds on? A) herbivore B) predator C) seed eater D) carnivore E) parasite

E

Which of the following statements about communities is not correct? A) Many plant species in communities seem to be independently distributed. B) Some animal species distributions within a community are linked to other species. C) The distribution of almost all organisms is probably affected, to some extent, by both abiotic gradients and interactions with other species. D) Ecologists refer to species richness as the number of species within a community. E) The trophic structure of a community describes abiotic factors such as rainfall and temperature affecting members of the community.

E

Which of the following statements concerning the control of community structure is false? A) A bottom-up community is controlled by nutrients. B) A top-down community is controlled by predators. C) Increasing the biomass of vegetation in a bottom-up community will increase herbivores. D) Increasing the biomass of vegetation in a bottom-up community will increase predators. E) Increasing the number of predators in a top-down community will decrease the biomass of vegetation.

E