Unit 5 Review • MHR 541Short Answers
In your notebook, write a sentence or a short
paragraph to answer each of the following questions.
11.Describe some features of the ecological niche
of the panda. Is the panda a generalist or a
specialist? Explain your answer.
12.Describe the phenomenon of biological
magnification. Give an example of a substance
that seems to have had an effect on other
organisms as a result of this phenomenon.
13.Define the term “demography.”
14.What four processes affect the size of
populations?
15.A random sample of 100 mice from an island
population are captured, marked, and released.
Two weeks later, a second random sample of
150 mice is captured, of which 25 are
recaptured marked individuals. Estimate the
size of the mouse population on this island.
16.The birth rate for a population of 100 mice
is 2.5 individuals per individual per month,
and the death rate for this same population is
1.3 individuals per individual per month. What
will be the size of this population one year
from now?
17.The replacement rate for a population of
annual plants is four individuals per
individual per year. If we start studying this
population when it consists of 100 plants, how
big will it be five years from now (assuming
environmental conditions remain constant)?
18.Examine the graph shown here and describe
what is happening in the portions of the curve
labelled (a), (b), and (c). Explain why growth is
slow or fast in each of these regions of the curve.
19.The carrying capacity for deer in a particular
environment is 500. What does this mean?
20.Why do introduced (exotic) species, such as
the zebra mussel, tend to display exponential
growth? Give two other examples of introduced
species.
21.Describe how density-independent and
density-dependent factors might interact to
limit the size of a moose population. Give
examples of each type of factor.
22.Many populations, such as those of lynx and
snowshoe hare, have cyclical population
densities. What does this mean? What are some
of the suggested explanations for the cycling of
snowshoe hare populations?
23.Differentiate between interspecific and
intraspecific competition, and describe the
effects of each on populations.
24.Using the following three terms in a short
paragraph, show the relationships among them:
biotic potential, environmental resistance,
carrying capacity.
25.What is survivorship? Describe three general
patterns of survivorship and give an example
of an organism that tends to fit each of these
patterns.
26.Distinguish between opportunistic (r-selected)
and equilibrial (K-selected) life histories with
respect to patterns of age-specific fecundity and
age-specific mortality. Give two examples of
organisms with each type of life history.
27.What type of environment tends to favour an
opportunistic (r-selected) life history? Why?
28.Describe the four stages of a demographic
transition in terms of how the birth rate, death
rate, and size of a population tend to change as
it passes through each stage.
29.Are all human populations in which fertility
rates are at or below replacement level
characterized by zero population growth?
Explain your answer.
30.Distinguish between perpetual, non-renewable,
and renewable resources, giving an example
of each.
31.Define the term “pollutant.” Give five examples
of pollutants.
32.In what way might deforestation enhance
global warming?
33.What is ozone? Describe how it benefits
humans and other organisms in some
circumstances and harms them in others.0
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