APES Chapter 6 Exam Review

The organisms that represent all of the different interacting species within an ecosystem make up a

• Population
• Community
• Trophic Level
• Biosphere

When individuals are found to be distributed evenly throughout an ecosystem it is often because

• they are interbreeding.
• resources are not limiting.
• they mate for life.
• they are territorial.

If a population of 100 birds increases to 120 birds the following year, r=__.

• 0.16
• 0.20
• 1.2
• 2

The intrinsic growth rate of a population

• directly affects environmental resistance.
• causes changes in birth rates without affecting death rates.
• causes changes in death rates without affecting birth rates.
• 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

• energy.
• water.
• food.
• climatic events, such as tornadoes.

An exotic species is one which ___ an ecosystem.

• is rare in
• is foreign to
• does not interact with other species in
• is the most dominant species in

Rapid growth may be temporarily be observed in a population in response to all of these EXCEPT

• elimination of a pollutant.
• elimination of predators.
• increase in food supply.
• introduction of a new parasite.

A laboratory experiment followed the growth of a flour beetle population over time.  At first the population increased dramatically but later growth slowed and the population 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?

• It has no effect on the growth of the population, as food scarcity is clearly the limiting factor here.
• It is clearly maladaptive as populations always do best when their densities rise as high as possible.
• It serves as a density-dependent means of population control.
• It serves as a density-independent means of population control.

Rabbits were introduced to Australia about 100 years ago for the purpose of hunting.  They have been multiplying, eating up the native vegetation, and destroying the native habitat of other small animals, ever since.  In the 1950's, in order to control the rabbit population, government scientists released the myxomatosis virus.  The virus, which dramatically reduced the rabbit population, is an example of

• a predator.
• a parasite.
• a cyclical pattern of growth.
• the effect of migration on growth.

Most parasites have evolved to ___ their host.

• kill
• only weaken
• have no effect on
• strengthen