Exam 55: Species Interactions

Black bears are most likely acting as mutualists when they eat

In an experiment involving two annual plants that grow in disturbed habitats, equal numbers of seedlings of the two species were grown together.Plant A grew much larger than plant B during the same time period.Would this interaction be considered asymmetrical? Why or why not?

Many interactions between plants and insects result in pollination.How does coevolution play a role in the development of these interactions?

Kangaroo rats live in the desert and forage at night.When there is bright moonlight, they forage in more covered areas.This strategy of defense against predators could best be described as

A forest is destroyed by fire, and then plant species begin to recolonize the burned site.Which types of species are likely to compete best in this environment?

Two species compete for a shared set of limiting resources.Over time, one of them declines in population size and becomes locally extinct.All factors are at work in this community except

Refer to the graph below showing one of the results from G.F.Gause's classic competition experiment on three species of Paramecium.Both of these species, P.aurelia and P.caudatum, feed on floating bacteria. Which statement best describes the relationship between the two species?

Several lizards of the genus Anolis live on Caribbean islands.They all feed on insects, but they feed in different areas of the habitat.For example, some live in leaf litter, others in tree branches, and still others on tree trunks or in surrounding shrubs.This variation in habitat and feeding locations enables various species of Anolis to share a habitat because of

A chimpanzee has a serious parasite infestation.She responds to this infestation by seeking out members of her troop and sitting with them while they groom her.She is most likely infested with

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.Differences in the distribution of larval and adult barnacles suggest that stellate barnacles are primarily restricted by _______ and rock barnacles are restricted by _______.

A small population of Canada lynx feeds on Arctic hares.Then snowshoe hares (the lynx's favorite prey) are introduced.The snowshoe hares reproduce rapidly, and their population explodes.Based on your knowledge of predatorprey interactions, what changes would you expect in the lynx population and in the population of Arctic hares, the lynx's previous prey?

The interaction in which fleas live on a dog and feed on its blood is best described as _______.

Refer to the figures showing results of laboratory experiments that grew two species of Paramecium together. What types of competition are occurring in each of the two graphs?

Two plant species live along a gradient, from a rich temperate valley floor to halfway up a mountain slope.In the valley, the two plants are competitors, but going up the gradient their relationship changes and becomes more and more commensal.This change in their relationship is most likely the result of

If the removal of a predator results in expansion of a spider's range, it is likely that the spider's _______ niche is larger than its realized niche in the presence of predators.

The partnership between plants and mycorrhizal fungi is best described as _______ mutualism.

When two species, such as Paramecium caudatum and P.bursaria, live in a limited environment and share resources, enabling both to coexist, their populations level off and both eventually reach their _______ for that environment.

Competition between coexisting species can be either direct or indirect.In which of these examples is the competition indirect (exploitative)?

The roots of many plants are connected to the hyphal strands of fungi.The fungi supply necessary water and minerals to the plants, and the plants supply carbohydrate nutrients to the fungi.This interaction is an example of

Two similar species of lemurs exist in Madagascar.One species eats leaves from the understory of trees, and the other eats leaves from the tops of those trees.This phenomenon would be described as