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Ecology Final IRSC
Ch. 13-18, 20-21, 27-29
Question | Answer |
---|---|
True or false: As a symbiotic relationship evolves, a mutualistic relationship is believed to evolve into a parasite-host relationship | false |
is a relationship between two species where both species experience a negative or adverse effect | competition |
A guild is defined as | species that carry out similar functions or exploit the same resource |
Parasitism | is where a parasite feeds off the host |
A community is a group of species whose environmental tolerances form consistent and integrated associations in space and time. Here, communities are well-defined with distinct edges. This view of a community is known as | Clements organismal concept |
According to the classical, but simplistic, Lotka-Volterra models, which of the following scenarios are true about predator-prey population cycling? | Changes in a predator population typically lag behind changes in the prey populations |
Which of the following is a true statement about comparing cannibalism and predation | Cannibals gain energy and reduce intraspecific competition; predators only gain energy. |
Each of the following is an environmental factor that may cause exclusion of an organism from a habitat, except... | abundant food |
the competitive exclusion principle | states that species that compete for all their resources can not coexist in the same habitat |
during the late spring and early summer, magnolia flowers open in large number. Honeybees that usually visit clover flowers for nectar begin to visit magnolia flowers for nectar instead. This is an example of... | prey switching |
each of the following statements about competition is true except | competition only occurs between closely-related species |
species richness is defined as | a number of species |
In a simple community food web, various species of grasses are eaten by grasshoppers and mice. The grasshoppers are eaten sparrows. Both the mice and sparrows are eaten by hawks. In this community, the grasshoppers are considered _____ | intermediate species |
changes in species composition and community structure along some environmental gradient is known as... | zonation |
Which of the following is a functional response by a predator, toward its prey? As the population of field mice increases, rat snakes | focus more on capturing field mice, ignoring cotton rats |
Dominant species within a community may be defined as | A) those that take up the most space. B) the most numerous. C) those with the most biomass. |
why are field experiments testing competitive interactions difficult to perform | most pollinators are generalists, feeding on many plant species, though they may focuz on one species at a given time |
____ is a means one individual attempts to alert others of the presence of a predator | an alarm call |
an ectoparasite would be most likely to be found in the ____ of a host | feathers |
According to the Lotka-Volterra models of interspecific competition | two competing species can coexist, or one will replace the other, depending on the carrying capacity and the effects of each species on the other. |
the competitive exclusion principle | states that complete competitors can not coexist in the same habitat |
compared to microparasites, macroparasites | have a longer duration of infects, are more persistent, have longer generation times |
The bright colors of the poisonous coral snake, with their bands of red, yellow and black, are an example of | warning coloration |
An example of a density-dependent type of a parasitic infection would be | a parasite that infects more individuals during times when the hosts gather together in groups. |
Which of the following layers of a terrestrial community absorbs the least sunlight | herb layer |
A grizzly bear catching and eating salmon moving upstream in a river is an example of ____ | carnivory |
In the Type III functional response curve of predation, the curves is a sigmoid or "S-shaped" curve. This may be caused by | A) a threshold of security of the prey. B) the predator developing a search image. C) predator switching to the more abundant prey. |
_____ is due to a parasite that has had a major impact on human populations | A) AIDS B) Bubonic plague C) Smallpox |
Though many factors are important in characterizing a terrestrial community, which of the following is the single most important variable in determining the structure and function of a terrestrial community? | the plants species present |
Which of the following statements about community structure is true | Some species may be considered dominant because their activities may affect the structure of the entire community |
Ecologists use diversity indexes to better quantify diversity communities so that they may be compared more easily. Diversity indexes take into account _____ within the community | both the number and relative abundance of species |
an example of a macroparasite is a _____ | flea |
The range of common usage of a single resource by two competing species is known as ____ | niche overlap |
Adult bacterial spirochetes responsible for Lyme disease are spread between mice and deer by the black-legged tick. The tick is an example of ____. | a vector |
Which of the following is a characteristic of early successional species | A) slow to mature B) disperse widely C) short lifespan |
____ is the term used for recycling of nutrients within an ecosystem involving processes of assimilation and decomposition | internal cycling |
bycatch is a major problem for fisheries because | A) it often includes juveniles and undersized individuals. B) it impacts many other species other than the target species. C) it is discarded, wasting valuable biomass |
during the latest stages of succession, diversity typically... | decreases |
the silvicultural technique in which only a few mature trees are removed from a given area is called... | selection sutting |
why does the primary productivity of agricultural lands rival or exceed most natural ecosystems | the very high nutrient input into agricultural systems |
Which of the following is an example of an output of nutrients, where nutrients can leave an ecosystem | A) harvesting of a crop B) organic matter carried by a stream C) carbon, in the form of carbon dioxide, released via respiration |
succession involves... | both autotrophic and heterotrophic species |
during the succession process, the highest species diversity is typically... | during the intermediate or middle stages |
Which combination of the environmental conditions would most decrease the rate of decomposition? | cool and dry conditions |
_____ is the process when a community changes over time | succession |
the amount of resource harvested per unit time is called... | yield |
decomposers... | mechanically and chemically breakdown organic material |
14. The process by which decomposers transform nutrients from an organic form into a mineral or inorganic form such that they are available to plants is known as ____ | mineralization |
When a predator enhances the success of inferior competitors by suppressing a superior competitor, the interaction is called... | keystone predation |
n a typical ecosystem, which of the following statements about ecological pyramids is true | in terrestrial ecosystems, autotrophs typically have the greatest biomass |
an ecosystem includes | A) the autotrophic of components of the environment. B) the consumers of the environment. C) the physical components of the environment |
Succession that occurs on a site that was previously occupied by a community is called ________ succession. | secondary |
Upwelling affects nutrient cycling in marine ecosystems by... | wind-driven water flow moving nutrient-rich bottom water toward the surface. |
Which of the following is a characteristic of swidden agriculture or shifting cultivation? | A) Productivity declines with each successive crop. B) Ash from fires is high in mineral nutrients. D) Felled trees and brush are burned to clear land for planting. |
________ is an economics technique employed to add and compare costs and benefits that occur at different points in time. | benefit-cost analysis |
primary succession would occur in which of the following situations? | a glacier recedes exposing the ground for the first time in 10,00 years |
an example of first level consumer is | white-tailed deer |
Increasing nutrient availability tends to ________ plant diversity in a community | increase or decrease (depending on initial conditions) |
Perhaps the greatest problem with models of sustainable harvest of fish is that they fail to incorporate ________ | economics |
In a lake, one species of sunfish is a superior competitor over another sunfish species. However, the gar is a predator that prevents the superior sunfish from competitvely excluding the second sunfish. This is an example of... | keystone predation |
When chemical fertilizers such as nitrates and phosphates move from agricultural fields to adjacent streams, they cause accelerated nutrient enrichment and related ecological effects, called... | cultural eutrophication |
The ____ is based on energy flow between trophic levels where the original source of energy is directly from living plant biomass moving to living animal biomass. | grazing food chain |
Which of the following interactions between species can alter the environment and affect the presence of other species. | A) competition B) mutualism C) predation |
Groups of sites within an area that are at different stages of succession are known as... | chronosequences |
True or False: Disturbances, such as fire, can sometimes increase coexistence between species and increase diversity. | true |
Which type of disturbance will most likely have the longest lasting effects on an ecosystem? | Harvesting timber by clear-cutting |
In a food web, an example of top-down control would be that.. | herbivores limit the primary producers |
_____ is the process by which decomposer organisms incorporate nutrients into organic forms to use for their own metabolism, growth and reproduction. | immobilization |
a null model in community ecology... | A) assumes that species are able to fully exploit their fundemental niche. B) assumes that species only interact with the physical environment. C) is a starting hypothesis to compare real communities. |