Choose the Best Answer
1. Ecology is often defined as the study of interactions between living things and
their physical environment. Which of the following is not a question of direct
interest to ecologists?
a. What factors influence abundance?
b. How is matter and energy passed from one living thing to another?
c. Why is a particular species no longer found in a given place?
d. Why is a particular plant or animal species found in one place but not in
another?
e. Why are some traits inherited from both parents and others from only
one parent?
2. Lichens, mosses, grass and sedges are conspicuous and abundant. Shrubs
are stunted and trees are absent. Long, cold winters; short, cool summers.
Average annual precipitation is from 5 to 45 inches. Which biome best matches
this description?
a. Deciduous (Temperate) Forest.
.
b. (Temperate) Grassland.
c. Coniferous (Boreal) Forest. d. (Subtropical) Desert. e. (Artic) Tundra.
Questions 3-5. A biology student studied the abundance and dispersion of 4
species in his own community of prairie plants that was divided into 35 plots by a
wire grid.
3. The student counted 25 individual Virginia wild rye plants in an unbiased
sample of 7 plots. What is the estimated number of Virginia wild rye in the
community?
a. 50.
b. 125.
c. 175.
d. 875.
e. none of these.
4. He completed his study of abundance and found: 35 plants of wild bergamot
in 5 plots; 120 plants of rattlesnake master in 20 plots; and 140 plants of tall
coreopsis in the entire community. Which species shows the highest density in
this community?
a. Wild Bergamot. b. Rattlesnake Master. c. Tall Coreopsis.
d. can’t be determined since the exact areas of the plots are not known.
5. He noted that the Wild Bergamot seedlings were close to a parent plant; where
as Virginia wild rye plants were scattered with no regularity or affinity. Thus, he
concluded that dispersion of Virginia wild rye was ________ and wild bergamot
was _________.
a. uniform; random.
b. random; clumped.
c. clumped; uniform.
d. clumped; random.
e. uniform; clumped.
6. 185 whooping cranes were counted in 2002 and a record population of 189
was counted in 2003. What was the finite rate of increase ()?
a. -0.022
b. 0.978
c. 1.021
d. 2.659
e. 4
7. A biologist decided to estimate how many largemouth bass were present in
Joe’s pond. He caught and marked 50 largemouth's and returned them to the
pond. Two days later he captured 90 bass of which 30 were marked. Assuming
that the sampling technique was not biased, how many largemouth bass are
likely to be living in the pond?
a. 110
b. 150
c. 170
d. 250
e. none of these
Questions 8 & 9. A biology student studied a population of woodcocks in a 40acre savanna. In 1990, she determined that natality was 55 per year, mortality 45
per year, immigration 15 per year, and emigration 5 per year.
8. If the initial population in 1990 was 20 woodcocks, what was the population
size at the end of the year?
a. 35
b. 40
c. 45
d. 50
e. none of these
9. In 1993, the population increased from 30 to 50. How does the finite rate of
increase () in 1990 compare with that in 1993?
a.  was greater in 1993.
c. Both are the same.
b.  was greater in 1990.
d. Can’t be determined.
Questions 10 & 11 refer to a population of duckweed (Lemna) that inhabits an
aquarium. A student interested in studying exponential population growth placed
10 plants in the aquarium. A week later she returned and counted 20 plants. The
following week there were 40 plants.
10. Assuming that growth continues at this rate, how many plants will be present
in
another two weeks?
a.
60
b.
80
c.
160
d.
320
e.
640
11. Since she had no way of counting all the plants when their numbers reached
more than a thousand, she simply estimated the proportion of the water surface
that was covered with duckweed. She determined that the aquarium was
covered with duckweed in 22 weeks. Assuming the growth rate she observed in
her earlier experiment applies, when was the aquarium half covered?
a. 11 weeks.
b. 17 weeks.
c. 20 weeks.
d. 21 weeks.
12. In humans and other species with high survivorship in most age classes,
rates of population growth are extremely sensitive to changes in age-specific
fecundity. Based on this result, programs to control human population growth
focus on:
a. Increasing mortality among the earliest age classes.
b. Lowering fertility rates through the use of birth control.
c. Delaying the age of first reproduction by improving access to education.
d. Both a and b are correct.
e. Both b and c are correct.
Questions 13 - 15. The population data for the human species, as well as six
geographical regions of the earth, is given below. This data is for mid-2004 as
reported by Population Reference Bureau.
Population estimate Rate of natural increase Doubling time
(In millions)
(% Per year)
(years)
World
Africa
North America
Latin America
Asia
Europe
Oceania
6,396
885
326
540
3,875
728
31
1.3
2.4
0.5
1.7
1.3
- 0.2
1.0
53
29
139
41
53
---62
13. The almost impossible rate of growth humankind is experiencing today is
seen by projecting out nearly 100 years into the future. If this doubling time is
maintained, the projected human population in the year 2110 will be over:
a. 7 billion.
b. 12 billion. c. 24 billion. d. 48 billion. e. 96 billion.
14. The doubling time for Africa is 29 years and the doubling time for Latin
America is 41 years. As a consequence of this difference in doubling times,
which statement is true?
a. Africa has a larger population.
b. Latin America has a larger population.
c. The average age in Africa is more than Latin America.
d. The average age in Latin America is more than Africa.
15. Based on the above data the population of Asia is expected to increase in a
year (mid-2004 --> mid-2005) by about:
a. 5,040,000
b. 50,400,000
c. 504,000,000
d. 5,040,000,000
16. The concept of demographic transition illustrates how changes in birth rates
and death rates have given rise to increased population growth in many countries
during the last century. For example, the population growth rate in Mexico
increased dramatically from 1930 through 1970. This is primarily due to a:
a. greater increase in per capita birth rate.
b. greater increase in per capita death rate.
c. greater decrease in per capita death rate.
d. greater decrease in per capita birth rate.
17. If most individuals in a population are young, why is the population likely to
grow rapidly in the future?
a. Many individuals will begin to reproduce soon.
b. The population has a skewed age distribution.
c. Immigration and emigration can be ignored.
d. Death rates will be low.
18. A student in laboratory used data from the Waldeim-Forest Home Cemetery
to compare survivorship around the turn of the century (1890-1920) with that
near the end of the century (1960-1990). The data indicated that mortality at an
early age (0-20 years) was:
a. lower in 1890-1920.
b. lower in 1960-1990
c. same in both time periods
Questions 19 & 20 refer to the following survivorship curves. Each curve may be
used once, more than once, or not at all.
a. Type I Survivorship. Very low mortality early in life that abruptly increases to
a very high level at the end of the life span.
b. Type II Survivorship. A constant mortality rate through the life span.
c. Type III Survivorship. Very high mortality early in life with low mortality in late
life.
19. ______ is the survivorship pattern for long-lived tree populations that have
many ungerminated seeds and small seedlings or saplings and that once mature
are protected by large size with little chance of death.
20. Most mortality is senescent mortality. This is the goal of public health. ______
21. Whooping cranes, sea turtles, and many other endangered species are
_______ lived and have _____ adult mortality, and _____ fecundity.
a. short, low, low
b. short, high, high.
c. long, low, low.
d. long, high, high.
e. long, low, high.
Questions 22 - 24 refer to the maternity table for a Uinta ground squirrel
population in a lawn in Utah.
x
D(x)
S(x)
l(x)
m(x)
l(x)m(x)
0-1
1-2
2-3
3-4
4-5
5-6
6-7
7
?
169
101
48
22
10
9
1000
359
190
89
41
19
9
0
1.000
0.359
?
0.089
0.041
0.019
0.009
0
1.75
2.76
2.76
2.76
2.76
2.76
0
0.628
0.524
?
0.113
0.052
0.025
0
22. How many ground squirrels died before their first birthday, i.e. what is D(0)?
a. 100
b. 169
c. 359
d. 641
e. 810
23. What is the net reproductive rate, i.e. what is Ro?
a. 1.34
b. 1.58
c. 1.75
d. 2.76
e. 15.55
24. If all Uinta ground squirrels 4 years old and older were removed before they
could reproduce, the population would immediately decline and then:
a. decrease slowly to extinction.
b. decrease rapidly to extinction.
c. increase more rapidly than before. d. increase less rapidly than before.
e. remains relatively unchanged.
25. A number of European countries such as Poland, Austria, Greece and
Portugal have birth rates equal to death rates. If this trend continues then the age
structures should have:
a. age groups that are relatively uniform in number.
b. a high proportion of younger relative to older age groups.
c. a high proportion of older relative to younger age groups.
d. a large number of individuals who are 100 years old or older.
e. very few middle aged individuals (those between the age 35-55).
Questions 26 - 28. Populations interact with one another . Five categories of
interaction are:
a. competition
b. mutualism c. predation d. commensalism e. parasitism
The above categories may be used once, more than once, or not at all.
26. A population interaction in which one population is benefited and the other is
not affected.
27. The roots of some legume species are infected by nitrogen fixing bacteria.
The bacteria are provided sugars and other nutrients. The plants are able to use
some of the nitrogen fixed by the bacteria. This is an example of _________.
28. A primary cause of the population cycles of the red grouse in British
moorlands.
29. Rhizobium, a prokaryote forming nodules in legumes, is primarily associated
with:
a. nitrogen fixation.
e. plant disease.
b. denitrification.
c. ammonification. d. decomposition.
30. The observation that per plant biomass is higher when Indian Grass is grown
at low density rather than high density is most likely an example of __________.
a. intraspecific competition.
b. interspecific competition.
c. intraspecific cooperation.
d. interspecific cooperation.
31. How do parasites differ from predators?
a. Parasites do not affect the density of their host species, but predators
affect thedensity of their prey.
b. Parasites tend to be very small relative to their host, and eat only
certain tissues.
c. Predators kill their prey more quickly and consume all of it.
d. Both a and b are correct.
e. Both b and c are correct.
Questions 32 & 33 refer to studies of the 10 year cycle of snowshoe hare and
lynx population in northern Canada.
32. A predator hypothesis states that at high density lynx eat so many hare that
the prey population crashes and shortly thereafter many lynx starve. Which of the
following observations support this hypothesis?
a. 95% of radio-collared snowshoe hare deaths are due to predation.
b. Predator exclusion nearly eliminated the decline phase of hare cycle.
c. Snowshoe hare populations show same fluctuations on an island where
lynxes are absent.
d. Both a and b support the predator hypothesis.
e. Both b and c support the predator hypothesis.
33. Recently, most population ecologists have reached a consensus that trophic
interactions are likely to generate these population cycles. Which of the following
best explains these trophic interactions?
a. Hare populations are unlimited by food supply and lynx kill more than
enough hare to account for the decline.
b. Food consumption increases as hare density increases, but all of the
available food is consumed and the hare starve; shortly thereafter the lynx
starve.
c. Lynx populations reach high density in response to increases in hare
density; at this density they eat so many hare that the prey population crashes.
d. Hare populations increase to such high levels that they run out of food,
but by that time the lynx population is so full that they migrate to other areas.
34. In a local old field, white-footed deer mice provide the major food source for
a small fox population. This predator-prey interaction has obvious advantages
for the fox population. What is the possible advantage for the mouse population?
a. Foxes are likely to eat other predators.
b. More fox pups are likely to survive when mice are abundant.
c. Since foxes eat mice, there is no possible advantage to mouse
populations.
d. Predation may act to keep mouse populations from exceeding their
food supply or some other critical environmental resource.
35. Of the four most abundant elements in living things, which do producers
procure directly from the atmosphere?
a. H and N
b. C and N
c. H and O
d. C and O
e. H and C
36. Net Primary Production (NPP) is highest in:
a. Desert.
b. Tundra.
d. Deciduous Forest.
c. Coniferous Forest.
e. Grassland.
37. Nitrogen is an important macronutrient and is a major ingredient of “plant
food” (fertilizer). Experiments with soil nitrogen and plant biomass indicate that:
a. all plant species respond to increased soil nitrogen in exactly the same way.
b. plant biomass increases with increases in soil nitrogen and then levels off.
c. increasing the amount of fertilizer added to soil increases plant biomass.
d. very high levels of nitrogen in the soil result in plants with yellow leaves.
e. plants do best when levels of nitrogen in the soil are low.
38. Herbivores are animals that receive most, if not all, of their nutrition from
plants. Much of recent research on herbivory has focused on this question: why
don’t herbivores consume more plants than they do. Which of the following is not
an explanation that biologists have routinely considered?
a. Herbivores commonly kill the plants they eat, thus they could be limiting their
own populations.
b. Herbivores could be kept in check by predation and disease.
c. Plant tissues could offer poor or incomplete nutrition.
d. Plants could defend themselves against attach by producing indigestible
wood or potent poisons.
39. When the newts are absent in artificial ponds, spade foot toad survival is
much higher than spring peepers. When the density of newts increases, spade
foot survival is lower than spring peepers. Predation is affecting a second type of
species interaction. This interaction is _____________.
a. mutualism b. commensalism c. competition d. parasitism
e. predation
40. What distinguishes a keystone predator?
a. It is extremely abundant.
b. It regulates its prey below the carrying capacity of the habitat.
c. It is a specialist, meaning that it preys on only one species.
d. It has a large impact on the community, even though it is not particularly
abundant.