Question 1

At a swim meet, all the swimmers in a race want to place first, but only the fastest swimmer can do so.The is an example of

Accepted Answer

A)  interspecific competition. 
B)  interference competition. 
C)  competitive exclusion. 
D)  resource partitioning. 
E)  exploitation competition.

Question 2

Which prey animal is using a morphological form of defense against predators?

Accepted Answer

A)  The frog that has a toxin in its skin 
B)  The katydid that looks like a dead leaf 
C)  Antelopes that remain together in herds 
D)  The opossum that "plays dead" 
E)  The octopus that shoots jets of ink to confuse predators

Question 3

Two snake species move into a new habitat.Both feed predominantly on crickets and grasshoppers.One species is able to feed both day and night, while the other is strictly diurnal.Over time, one of the species becomes locally extinct.This form of competition is known as _______.

Accepted Answer

The answer of Two snake species move into a new...

Question 4

Which interaction can correctly be labeled coevolution?

Accepted Answer

A)  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 
B)  The tendency of coyotes to respond to human habitat encroachment by including house pets in their diets 
C)  A genetic change in wolves that allows them to tolerate human presence and human food 
D)  The ability of termites to adapt to human habitations 
E)  The ability of mice to survive in a variety of novel environments

Question 5

African wild dogs avoid competition with lions by living in areas lions are unlikely to inhabit.A species might also be a fugitive species if it

Accepted Answer

A)  is a sessile species. 
B)  is an efficient predator. 
C)  uses different food resources. 
D)  is good at using camouflage. 
E)  is competitively subordinate to another species.

Question 6

The Rhode Island salt marsh experiments on the rush Juncus gerardii and the shrub Iva frutescens showed that Iva dominates and Juncus has a low biomass in the high intertidal zone.However, in the low intertidal, where salinity and waterlogging are greater, Iva depends on Juncus for survival.Which general statement best describes the cause of the change in this relationship?

Accepted Answer

A)  Stressful environments increase competition between species. 
B)  Stressful environments change mutualists or commensals into competitors. 
C)  Environmental variation is necessary to enable certain species to survive. 
D)  Environmental variation may cause communities to have a higher biodiversity. 
E)  Environmental variations may change competitors into mutualists or commensals.

Question 7

Which relationship is least likely to result in coevolution?

Accepted Answer

A)  Mutualism 
B)  Parasitism 
C)  Predation 
D)  Competition 
E)  Amensalism

Question 8

Many relatively large ectoparasites, such as leeches and mosquitoes, are only casually associated with their hosts; that is, they feed and then leave.However, whale lice spend their entire lives on one whale.A difference in _______ has most likely caused the evolution of this difference in ectoparasite life style.

Accepted Answer

A)  size (lice are smaller than most other ectoparasites) 
B)  species (lice have different basic needs than other ectoparasites) 
C)  habitat (in the ocean, lice would likely be unable to find a new host) 
D)  host behavior (whales are unable to remove lice by grooming) 
E)  disease (lice are less likely to cause disease than other ectoparasites)

Question 9

In coral reefs, the cells of the cylindrical coral polyp contain single-celled photosynthetic algae, or zooxanthellae.Coral polyps filter organic material from water and metabolize it, forming carbon dioxide and nitrogenous wastes that zooxanthellae use in photosynthesis.The oxygen and sugars they form in turn are used by coral polyps and dinoflagellates for metabolism.Many corals cannot feed successfully when they lose their zooxanthellae, but zooxanthellae can usually grow and reproduce outside of the corals.For zooxanthellae, this interaction is _______; for corals, it is _______.

Accepted Answer

A)  commensalism; mutualism 
B)  mutualism; commensalism 
C)  obligate mutualism; facultative mutualism 
D)  facultative mutualism; obligate mutualism 
E)  facultative mutualism; facultative mutualism

Question 10

Which interaction is a positive interaction?

Accepted Answer

A)  Parasitism 
B)  Predation 
C)  Herbivory 
D)  Competition 
E)  Mutualism

Question 11

The interaction of the ant and the acacia tree, in which the ant builds nests in the acacia's thorns and feeds on its nectar while also defending the acacia from herbivores, is most likely a product of

Accepted Answer

A)  chance. 
B)  coevolution. 
C)  competition. 
D)  favorable climates. 
E)  changing environments.

Question 12

The desert-dwelling yucca moth lays its eggs in the blossoms of the yucca plant and yucca seeds provide food for its larvae.The yucca plant depends on this moth for pollination.The two organisms are completely dependent on each other.In Great Britain, there are no yucca moths, and the yucca flowers produce no seeds.This highly specialized interaction likely evolved only in the desert environment because the two species

Accepted Answer

A)  exploited the best available resources in a high-diversity environment. 
B)  were not able to withstand the harsh environment of the British Isles. 
C)  were not compatible in Great Britain because the yucca did not produce seeds. 
D)  became interdependent because both could reliably be found even in the stressful desert environment. 
E)  were the only species available that provided the right nutrition and the right method of pollination required by the other.

Question 13

While pursuing its prey, a bear destroys a shrub.The relationship between the bear and the shrub would be described as

Accepted Answer

A)  herbivory. 
B)  competition. 
C)  amensalism. 
D)  commensalism. 
E)  predation.

Question 14

In Paine's classic study of sea star predation on mussel populations, he showed that in the absence of sea stars, experimental plots lost approximately half of the sessile invertebrate species usually present.This result suggests that

Accepted Answer

A)  mussels act as a keystone species in the rocky shore community. 
B)  high prey density is necessary to maintain community species diversity. 
C)  predators can maintain community species diversity by controlling prey density. 
D)  some sessile invertebrate species can survive only in the presence of mussels. 
E)  some sessile invertebrate species can survive only in the presence of sea stars.

Question 15

An "active pursuit" predator, such as a cheetah, is adapted to catching prey by having excellent eyesight and being extremely fast.The most effective type of defense a prey animal might use to avoid capture by this predator is likely

Accepted Answer

A)  mimicry. 
B)  warning coloration. 
C)  secreting a toxic chemical. 
D)  holding still or "playing possum." 
E)  having a hard shell or tough skin.

Question 16

Two species of barnacles, stellate and rock barnacles, occupy the rocky intertidal zone of the Scottish coast and illustrate factors that can determine species distribution in a community.Larvae of both species settle throughout the intertidal zone, but adult barnacles occupy specific zones.The smaller stellate barnacle lives only in higher zones, where the environment dries out between high tides.The larger, faster-reproducing rock barnacle lives only at lower zones.If rock barnacles were entirely removed from this community, what would most likely happen to the population of stellate barnacles?

Accepted Answer

A)  They would go extinct. 
B)  They would leave the community. 
C)  There would be little or no change in their population. 
D)  They would expand their range to include both the low and high areas. 
E)  They would remain at high levels, and their population would increase.

Question 17

Cheetahs are active-pursuit predators; they capture prey by chasing them down.Leopards, in contrast, are stealth or ambush predators; they watch their prey from a concealed location, and when the prey gets close, they execute a rapid surprise attack.What differences in body type, physiology, or behavior would you expect these two types of predators to have?

Accepted Answer

The answer of Cheetahs are active-pursuit predators; they capture prey...

Question 18

Photosynthetic single-celled dinoflagellates, called zooxanthellae, live within coral polyps.Zooxanthellae use CO2 and nitrogenous wastes from the polyps to form oxygen and sugars, which in turn are used by both polyps and zooxanthellae for metabolism.As water temperatures warm, polyps eject their zooxanthellae, causing the coral to turn a bleached white.Corals slowly starve without zooxanthellae.As climate change causes warmer waters, we may expect to see a(n) _______ in corals as the number of zooxanthellae _______.

Accepted Answer

A)  increase; increases 
B)  increase; decreases 
C)  decrease; decreases 
D)  decrease; increases 
E)  population stabilization; levels off

Question 19

In a mutualistic interaction between a sessile species and a motile species, the sessile partner often receives benefits that are only available because of the motile species.In a pollination interaction, the plant would be least likely to receive which benefit as a result of the interaction?

Accepted Answer

A)  Acquisition of nutrients 
B)  Reproduction 
C)  Increased sexual diversity 
D)  Possible dispersion to new habitats 
E)  Possible increased efficiency of seed production

Question 20

Refer to the graph below, showing population cycles of snowshoe hares and their predator, Canada lynx.Population numbers were collected when both populations were trapped for the fur trade.  Assuming minimal variations in environment over the period of the study, which statement best represents the interaction of the hare and lynx?

Accepted Answer

A)  For several years after 1900, the populations of hare and lynx were almost equal. 
B)  The peak hare population was almost 160,000; the peak lynx population was about 6,000. 
C)  The peak hare population was almost 160,000; the peak lynx population was about 80,000. 
D)  When the lynx population neared zero, the hare population neared zero shortly thereafter. 
E)  Lynx populations are consistently lower, and their peaks precede those of hare populations by several years.

Exam 55: Species Interactions