60 terms

APES ch 6 study guide

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the organisms that represent all of the different interacting species within an ecosystem make up a...
community
which type of population distribution can enhance protection from predators
clumped distribution
which individuals are found to be distributed evenly throughout an ecosystem it is often because
they are territorial
animals are sometimes randomly distributed across an ecosystem within a population because of...
the fact that resources are not limiting
which of the following is true?
1. some populations grow without restraint as long as resources are not limiting
2. the size of some pop. tends to remain relatively constant over time
3. in some populations, size fluctuates in a cyclical pattern
4. population size may vary sporadically in response to environmental changes
all of them
if a population of 100 birds increases to 120 birds the following year, r=________
0.20
a population of river otters has a growth rate of (r) of 0.2 per year. If the population starts out with 50 individuals and there is no migration, how many would you expect after one year? After 2 years?
60; 72
at the start of a study, there were 200 spotted salamanders in an old growth forest patch in western Oregon. Over the next year, a biologist tracking the salamanders saw that 25 new salamanders hatched and 5 died. Thus, r for this year was...
0.1
which is true?
1. under ideal conditions, bacteria and eagle populations both grow exponentially
2. populations of bacteria, which grow much faster than eagles, show exponential growth, where eagles do not
3. bc eagles grow to a larger size than bacteria, they have a j-shaped growth curve
4. growth curve of bacteria is never constrained by K
5. eagles are r-selected species, which bacteria are k selected species
under ideal conditions, bacteria and eagle populations both grow exponentially
the intrinsic growth rate of a population...
is the maximum rate at which a population may increase
an ecosystem's carrying capacity for a population is determined by all of the following factors except...
a. space
b. energy
c. water
d. food
e. climatic events, such as tornadoes
climatic events, such as tornadoes
a population of rabbits, introduced to an island, has rapid growth for a few years; then its growth slows. The pop becomes stable bc...
the carrying capacity has been reached
Some predators feed preferentially on the most abundant prey. This type of predation is...
density dependent
an exotic species is one that ______________ an ecosystem
is foreign to
rapid growth may be temporarily observed in a population in response to all of these except...
a.elimination of pollutant
b. elimination of predators
c. increase in food supply
d. introduction of a new parasite
e. introduction into a new habitat
introduction of a new parasite
during the winter of 1999, minimum temperatures did not get much below freezing in an oregon pond, and the following summer, large mosquito populations were observed. In the winter of 2000, frost came early, and most ponds froze ofr 3 months. In the following summer, very low mosquito populations were observed. This is an ex of....
density-independent regulation
a laboratory experiment followed the growth of a flour beetle pop over time. At first, the pop increased dramatically but later growth slowed and the pop size leveled off. While food was abundant, it was noticed that flour beetles resorted to eating their own eggs when densities got high. What can we conclude about cannibalism in this species?
is serves as a density-dependent means of population control
populations of predators increase when populations of prey are high because...
a.predators' nutrition is better
b. it is easier to find prey
c. prey population may be weakened by competition for resources
d. reproductive output may increase
e. all of the above
all of the above
an important density-independent factor limiting population size is...
weather
rabbits were introduced to Australia about 100 years ago for hunting. They have been multiplying, eating up the native vegetation, and destroying the native habitat of other small animals. in the 1950s, in order to control rabbit pop, gov scientists released the myxomatosis virus. The virus, which reduced pop, is an example of....
a parasite
when mosquitoes are very abundant, purple martins flock to the area and specialize on them. When mosquito populations are not large, purple martins are similarly scarce and feed on other insects. This is an example of....
density-dependent regulation
most parasites have evolved to ___________ their host
only weaken
a study conducted in the laboratory used wasps as predators and bean weevils as prey. The wasps lay their eggs on weevil larvae, which provide food for the newly hatched wasps. What would be the most likely hypothesis for the outcome of this experiment
the predator population increased and decreased slightly later than the prey population
which of the following is a density-independent event that could limit the size of a population?
the accidental spill of a pesticide that causes the pop to decrease
which of the following is not a type of interspecific interaction
speciation
the biologist who studies interactions at the community level investigates interactions between
populations of more than one species
predation is similar to ___________ in that both types of relationship benefit one of the interacting species while the other is harmed
parasitism
if you were studying the niche of a species of bird, you might study....
all of the above
two species that have a high degree of niche overlap will
compete intensely
if similar species each occupy a smaller niche when they live together than they would if they live alone, they are said to be....
partitioning resources
which of these outcomes is likely in a natural situation when two closely related species compete for resources in the same habitat
population size and distribution of each species may be reduced
the concept that two species cannot occupy the same ecological niche is called
competitive exclusion
when interspecific competition occurs between two species with similar niches....
both species are harmed because access to resources is reduced
earthworms live in many grass and forest ecosystems and aerate soil as they burrow. They ingest organic matter and travel between soil horizons. These traits refer to the _______________ of the earthworm
niche
over the past century, sagebrush has dramatically expanded its range over the colorado plateau's grasslands. This has been attributed to the overgrazing of the area's grasses by cattle and sheep. This example indicates....
the range of sagebrush is normally limited by competition with grasses
if an insect eats the lettuce seedlings in your yard, it is acting most like a
herbivore
if you find a brightly colored insect resting on a leaf, it is most likely to be....
poisonous or distasteful
which of the following statements best describes the reason why bright coloration is an effective defense against predators?
the predators can see the color and, either through natural selection or learning, avoid the prey
a species that is a mimic often....
behaves similarly to another species
which of these might a predator use to better enable it to catch its prey
camouflage
which behavioral response to the threat of predation is most likely to be selected for in a species that uses camouflage for protection?
a motionless behavior
a close interaction between 2 different species, in which one species benefits and the other is unaffected, is....
commensalism
the term "symbiosis" included which of the following relationships between organisms of two different species?
mutualism, commensalism, parasitism
which of the following is not an example of 2 organisms in a mutualistic relationship
humans and the protozoa that cause malaria
which of the following is not an example of 2 organisms in a parasitic relationship
a carnivorous plant and the insect it captures and digests
what characteristic best distinguishes predators from parasites
parasites live on or within their prey
tapeworms in the human gut are an example of....
parasites
many plants have their roots infected with a specialized fungus. The plant supplies carbon to the fungus and the fungus supplies nutrients to the plant. This is an example of ________________ association
mutualistic
a species that plays a major role in determining the structure of its ecological community is....
a keystone species
the black rhinoceros is considered to be a keystone species because...
removal of rhinoceroses from their community would result in drastic changes in the ecological structure of the community
a certain species of animal represents just 3% of the biomass in its ecosystem. We might classify this as a keystone species if its elimination...
caused the diversity of the plant community to sharply decrease
when all vegetation is removed from a site by human activity or by natural forces such as volcanic activity, ____________ species are the first to colonize the site
pioneer
which of the following is not true of the general pattern of succession, from a recently disturbed terrestrial site to stable, self-sustaining forest community?
total biomass tends to decrease
____________ succession begins on bare rock after glaciers have passed, or on newly formed volcanic islands
primary
the first plant community that forms on bare rock often includes organisms such as...
lichens and mosses
after a forested area such as a national forest is clear cut, what type of succession occurs
secondary
which of the following is not likely to characterize pioneer plant species involved in primary succession
slow growing, long lived perennial
all of the following are factors that influence species richness of a community except...
succession
which of the following statements is correct in reference to species richness
species richness is greatest in latitudes near the equator
habitat size and community distances are the basis for
island biogeography