Chapter 27

Woodpeckers and squirrels both nest in tree cavities. This is an example of an interspecific competition. True or False?

True

Why is the African elephant considered a keystone species? A) The removal of elephants from their community would result in drastic changes in the ecological structure of the community. B) It is the largest organism in its community. C) Elephants live in large cooperative herds that dominate other smaller groups within the community. D) Elephants eat more food than any other species in their community. E) Elephant populations are larger than the populations of any other organisms in their community.

A) The removal of elephants from their community would result in drastic changes in the ecological structure of the community.

If you find a brightly colored insect resting on a dead leaf, the insect is likely to A) be poisonous or distasteful. B) be prey for birds. C) be camouflaged. D) have startle coloration. E) have aggressive mimicry.

A) be poisonous or distasteful.

Two species that have a high degree of niche overlap will A) compete intensely. B) speciate. C) interbreed. D) be in a predator-prey relationship. E) coexist peacefully.

A) compete intensely.

The concept that two species cannot occupy the same ecological niche at the same time is called A) coevolution. B) mutualism. C) succession. D) the competitive exclusion principle. E) predation.

D) the competitive exclusion principle.

The first organisms to colonize a disturbed ecosystem are the climax species. True or False?

False

Organisms introduced as biocontrols for an invasive species can harm native species. True or False?

True

Parasites are generally smaller than their host. True or False?

True

Parasitism is a relationship in which one species benefits and the other does not benefit. True or False?

True

Some toxic animals are brightly colored, as a means of warning others of their danger. True or False?

True

The keystone species in the African savanna is the elephant. True or False?

True

The most common pioneer species are mosses and lichens. True or False?

True

A predator lures its prey nearby by looking like the prey's favorite food. This is referred to as ________ ________.

aggressive mimicry

The spotted brown and black coats of mountain lion cubs make it difficult for predators to find them. This is known as ________.

camouflage

The stable community that tends to persist in an area after succession is known as the ________ community.

climax

he productivity of an ecosystem usually ________ through succession.

increases

The bright coloration of toxic tree frogs is an example of ________ ________.

warning coloration

The physical home of a species is its ________.

habitat

An animal that only eats plants is a(n) ________.

herbivores

Many plants are mycorrhizal: Their roots are infected with a specialized fungus. The plant supplies carbon to the fungus, and the fungus supplies nutrients to the plant. The relationship between these plants and the mycorrhizal fungi is an example of a ________ association. A) mutualistic B) competitive C) parasitic D) successional E) predator -prey

A) mutualistic

Earthworms live in many grass and forest ecosystems, and they aerate the soil as they burrow. They also may mix soil layers as they ingest organic matter and travel between layers. These traits, taken collectively, make up the ________ of the earthworm. A) niche B) physical home C) community profile D) ecosystem profile E) resource partition profile

A) niche

Succession that begins on bare rock after glaciers have passed, or on newly formed volcanic islands, is A) primary. B) secondary. C) allogenic. D) pioneer. E) autogenic.

A) primary.

Ornithologists visiting an island find two species of birds that appear nearly identical except for bill size. Which of the following is the most likely explanation for their discovery? A) There is natural random variability. B) Coevolution of the two species has resulted in resource partitioning between the species. C) Mutations have resulted in an inferior species with defective bills. D) They aren't separate species. E) The birds need camouflage for protection from predators.

B) Coevolution of the two species has resulted in resource partitioning between the species.

Fleas feed on the blood of dogs, cats, and people. What is this ecological relationship called? A) Predation B) Parasitism C) Mutualism D) Resource partitioning E) Competition

B) Parasitism

Humans contract bacterial infections such as tuberculosis or syphilis. What is this ecological relationship called? A) Predation B) Parasitism C) Mutualism D) Resource partitioning E) Competition

B) Parasitism

Harmless king snakes mimic the color patterns of venomous coral snakes, which serve as models. If avoidance were based solely on prior predator experience with the model, what do you predict would happen in areas where coral snakes were never present? A) Predators would initially attack and eat king snakes but soon learn to avoid them. B) Predators would attack and eat king snakes. C) Predators would avoid king snakes. D) Predators would initially avoid king snakes but soon learn to attack and eat them. E) No predictions can be made based on the information given.

B) Predators would attack and eat king snakes.

After a forested area such as a national forest is clear-cut, what type of succession occurs? A) Primary B) Secondary C) Subclimax D) Climax E) Biome

B) Secondary

The process by which two interacting species act as agents of natural selection on one another is called A) mutualism. B) coevolution C) parasitism. D) mimicry. E) symbiosis.

B) coevolution

Over the course of their evolutionary histories, the timing of flowering, the spacing of plants, and the nectar rewards of flowering plants have influenced the foraging behavior of bees, which in turn has influenced the morphology of flowers. This process is an example of A) adaptive radiation. B) coevolution. C) competitive exclusion. D) convergent evolution. E) niche partitioning.

B) coevolution.

In ________, the interaction between two species harms both of them. A) coevolution B) competition C) mutualism D) parasitism E) symbiosis

B) competition

A species that is a mimic may A) produce chemicals that deter predators. B) have behavior similar to that of another species. C) resemble its surroundings. D) use bright colors to warn that it is harmful. E) produce "smoke screens."

B) have behavior similar to that of another species.

Competition between the members of two species is A) always very intense and is referred to as intraspecific. B) most intense when the species are most similar and is referred to as interspecific. C) unusual and is referred to as interspecific. D) very common and is referred to as intraspecific. E) least intense between similar species and is referred to as interspecific.

B) most intense when the species are most similar and is referred to as interspecific.

The biologist who studies interactions at the community level investigates interactions among A) organisms of one species. B) organisms of more than one species. C) animals of one species. D) social animals (such as insects). E) ecosystems.

B) organisms of more than one species.

Fleas on a dog are an example of A) predators. B) parasites. C) hosts. D) mutualists. E) prey.

B) parasites.

In the rain forests of Panama, scientists found a colony of tree-dwelling black ants where some individuals had red abdomens. When examined, the scientists determined that the ants with red abdomens were infected with roundworm eggs. Birds would prey on these ants, mistaking their red bellies for berries. In the interactions among the tree-dwelling black ants, the roundworms, and the birds, the roundworms are the A) predators. B) parasites. C) hosts. D) mutualists. E) prey.

B) parasites.

Insects that feed on plants without consuming them completely may be classified as A) predators. B) parasites. C) hosts. D) mutualists. E) prey.

B) parasites.

Mosquitoes are A) predators. B) parasites. C) hosts. D) mutualists. E) prey.

B) parasites.

When a community like the tallgrass prairie is maintained by recurring disturbances such as periodic fires set by Native Americans or by lightning, a ________ community exists. A) pine forest B) subclimax C) climax D) pioneer E) deciduous

B) subclimax

The next time you need to mow the grass, you can excuse yourself, saying that by mowing you are helping to maintain a man-made A) climax community. B) subclimax community. C) biome. D) ecosystem. E) population.

B) subclimax community.

Birds follow a herd of water buffalo to catch insects that are disturbed as the large herbivores walk through the grass. When large predators are near, the birds fly into the air and make warning calls. What is the ecological relationship between the birds and the herbivores called? A) Predation B) Parasitism C) Mutualism D) Resource partitioning E) Competition

C) Mutualism

Plants called legumes have chambers in their roots that house nitrogen-fixing bacteria. Nitrogen-fixing bacteria get both a place to live and energy while supplying nitrogen to a plant. What is this ecological relationship called? A) Predation B) Parasitism C) Mutualism D) Succession E) Competition

C) Mutualism

What ecological process causes a lake to change into a marsh over a long period of time? A) Eutrophication B) Competitive exclusion C) Succession D) Extinction E) Coevolution

C) Succession

A predator might use ________ to enable it to catch its prey. A) startle coloration B) warning coloration C) camouflage D) symbiosis E) coevolution

C) camouflage

In the Australian outback, emus (a relative of the ostrich) feeding in the open brush lands have coloration similar to the surrounding bushes. This is an example of A) warning coloration. B) mimicry. C) camouflage. D) coevolution. E) interspecies competition.

C) camouflage.

A certain species of animal represents just 3% of the biomass in its ecosystem. We might classify this as a keystone species if its removal A) allowed an even rarer species to increase in numbers and take its place. B) caused 2% of the other species in the community to disappear. C) caused the diversity of the plant community to decline by 40%. D) caused plant biomass to increase by 5%. E) had no effect on the community whatsoever.

C) caused the diversity of the plant community to decline by 40%.

Trees often produce secondary chemicals to deter herbivores from feeding on their leaves; in turn, many herbivores have developed ways of avoiding or detoxifying these chemicals. This is an example of A) competitive exclusion. B) predatory avoidance. C) coevolution. D) parasitic evolution. E) parasite predation.

C) coevolution.

In the rain forests of Panama, scientists found a colony of tree-dwelling black ants where some individuals had red abdomens. When examined, the scientists determined that the ants with red abdomens were infected with roundworm eggs. Birds would prey on these ants, mistaking their red bellies for berries. In the interactions among the tree-dwelling black ants, the roundworms, and the birds, the ants are the ________ for the roundworms. A) predators B) parasites C) hosts D) mutualists E) prey

C) hosts

An example of ________ is when birds feed on parasitic insects they pick off the skin of large animals such as elephants or bison. A) predation B) parasitism C) mutualism D) resource partitioning E) competition

C) mutualism

Clownfish live within the tentacles of sea anemones. The anemone protects the fish from predators, and the clownfish cleans the anemone. This relationship is an example of A) succession. B) competition. C) mutualism. D) parasitism. E) predation.

C) mutualism.

If similar species each occupy a smaller niche when they live together than they would if they lived alone, they are said to be A) involved in succession. B) involved in intraspecific competition. C) partitioning their resources. D) coevolving. E) increasing niche overlap.

C) partitioning their resources.

The biotic portion of an ecosystem includes the plants, animals, and water. True or False?

False

A species that plays a major role in determining the structure of its ecological community is A) a predator. B) a dominator species. C) the most abundant species in the community. D) a keystone species. E) the species with the largest size.

D) a keystone species.

An ecological niche A) is formed by the physical environment only. B) depends on the weather. C) is a constantly changing place. D) cannot be shared by two species. E) is the same thing as a habitat.

D) cannot be shared by two species.

The first community that forms on bare rock often has organisms such as A) herbs and conifers. B) grasses and weeds. C) broad-leaf trees and conifers. D) lichens and mosses. E) woody shrubs and conifers.

D) lichens and mosses.

A storm strips an island in Lake Superior down to bare rock. The first organisms to recolonize the island are most likely A) balsam firs. B) junipers. C) blueberries. D) lichens. E) yarrow.

D) lichens.

Intraspecific competition limits population size. True or False?

True

Predation is similar to ________ in that both types of relationship benefit one of the interacting species while harming the other. A) coevolution B) competition C) mutualism D) parasitism E) symbiosis

D) parasitism

The Masai people of Africa regularly consume the blood and milk of their cattle. Based on this information alone, we might classify the relationship between the Masai and cattle as A) coevolution. B) mutualism. C) competition. D) parasitism. E) predation.

D) parasitism.

Two species of buttercup are found in the same field in South Dakota, but they emerge at different times: One species emerges and flowers in early spring, and the other species does not emerge until late summer, after the first species has set seed. This is probably an example of A) habitat fragmentation. B) niche fragmentation. C) niche realignment. D) resource partitioning. E) intraspecific competition.

D) resource partitioning.

An effective, bright, and very distinct color pattern that a prey species can display suddenly to scare a predator is called A) modeling. B) aggressive mimicry. C) mimicry. D) startle coloration. E) camouflage.

D) startle coloration.

Over the past century, sagebrush has dramatically expanded its range over the Colorado plateau's grasslands. This development has been attributed to the overgrazing of the area's grasses by cattle and sheep. This example indicates that A) grazing has no effect on the distribution of plants. B) sagebrush could not exist anywhere in the absence of cattle and sheep. C) sagebrush is the dominant competitor over grasses. D) the range of sagebrush is normally limited by competition with grasses. E) the relationship between sagebrush and grasses is mutualistic.

D) the range of sagebrush is normally limited by competition with grasses.

Which behavioral response to the threat of predation is most likely to be selected for in a species that uses camouflage for protection from predators? A) A quick escape response B) Sudden display to startle the predator C) Cooperative behavior D) Behavior that mimics the behavior of the predator E) Motionless behavior

E) Motionless behavior

In the process called ________, interactions between species can limit population size, but can also influence the physical characteristics and behaviors of the interacting populations. A) succession B) mutualism C) camouflage D) symbiosis E) coevolution

E) coevolution

A caterpillar develops toxic spikes to deter the bird that preys on it. Over time the bird develops a digestive enzyme that neutralizes the toxin. This is an example of A) an invasive species. B) parasitism. C) mutualism. D) mimicry. E) coevolution.

E) coevolution.

If an insect eats the lettuce seedlings in your yard, it is acting most like a(n) A) omnivore. B) host. C) mutualist. D) carnivore. E) herbivore.

E) herbivore.

Two families of feral cats move into the same barn. One family preys on the mice; the other preys on the pigeons. This behavior is an example of A) parasitism. B) interspecific competition. C) mutualism. D) ecosystem profile. E) resource partitioning.

E) resource partitioning.

Shade-tolerant plant species are generally found early in succession and are replaced by hardier, shade-intolerant species. True or False?

False

Startle coloration is used to attract mates. True or False?

False

A keystone species is the most numerous species in an ecosystem. True or False?

False

Hawks that eat field mice are practicing mutualism. True or False?

False

In a mutualistic relationship, one species benefits and the other is harmed. True or False?

False

In a stable ecosystem, the number of predators is greater than the number of prey. True or False?

False

In all symbiotic relationships, both species involved benefit from the association. True or False?

False

In most environments, two or more organisms occupy identical niches. True or False?

False

In mutualistic interactions, one species is harmed, and one benefits. True or False?

False

Lichens are a symbiosis between a fungus and a plant. True or False?

False

Parasites kill their hosts, but predators do not kill their prey. True or False?

False

Invasive species outcompete native species because they lack predators and have high reproductive rates. True or False?

True

A lichen is a mutualistic relationship between a fungus and an alga. True or False?

True

In a process called coevolution, two species exert natural selection pressures on each other. True or False?

True

The rocks and weather that influence succession are examples of ________ factors.

abiotic

Similar climax communities distributed over a very large geographical area are known as ________.

biomes

The ________ ________ principle states that two species cannot occupy the same niche in the same habitat at the same time.

competitive exlusion

Bison are a ________ species in the prairie, helping to maintain the grasses, opening water holes and wallows, and creating the ecological framework for the prairie ecosystem.

keystone

A bat pollinates a plant while obtaining nectar from it. This behavior is an example of ________.

mutualism

A protist lives in the gut of a termite, breaking down the cellulose that the termite ingests and providing glucose to benefit both of them. This kind of relationship is called ________.

mutualism

Parasites act as agents of ________ ________, leading to changes in the host population that make it more resistant to the parasite.

natural selection

Every species occupies a unique ecological ________ that encompasses all aspects of its way of life.

niche

Succession in small ponds and lakes is usually dependent on the input of ________ from outside the ecosystem.

nutrients

A ________ feeds on another organism without killing it.

parasite

When all vegetation is removed from a site by human activity or by natural forces such as volcanic activity, ________ species are the first to recolonize the site.

pioneer

Succession after a catastrophic disturbance such as a volcanic eruption is referred to as ________ succession.

primary

Two weed species live in the same patch of ground. One has very deep roots to tap into ground water. The other has broad, shallow roots to take advantage of the frequent light rains that don't penetrate very deeply into the soil. This is an example of ________ ________.

resource partitioning

Along many southern bayous you can see the remnants of old plantations that have been reclaimed by the forest and swamp in a process known as ________ succession.

secondary

Succession after a disturbance such as forest harvest or a landslide is referred to as ________ succession.

secondary