KEY
Ecology Pre-Test on Part A
Use the following diagram to answer questions #1 – 14:
1. The correct sequence of the food chain involving these organisms is
A. A-B-C
B. B-C-A
C. B-A-C
D. C-A-B
2. Which organism is part of a population having the least total biomass? B
3. Which organism is part of a population having the greatest total biomass? C
4. Which organism is a first-order consumer? A
5. Which organism is a second-order consumer? B
6. Which organism would be present in the greatest numbers? C
7. Which organism would be present in the fewest numbers? B
8. Which organism is an herbivore? A
9. Which organism is a carnivore? B
10. Upon which organism do the others ultimately depend for energy? C
11. Which organism has the least energy available to it? B
12. Which organism is on top of the pyramid of numbers? (has the fewest number of organisms) B
13. Which organism is on the lowest level of the pyramid of numbers? (has the highest number) C
14. Which organism is on the lowest level of the pyramid of energy? (has the most energy) C
15. If the total weight (biomass) of producers in an ecosystem was 100 tons, what would you expect the total
weight of secondary consumers to be?
A. 0.1 ton
B. 1 ton
C. 10 tons
D. 100 tons
E. 1,000 tons
16. Action of decomposers leads to recycling of
A. nitrogen
B. water
C. carbon dioxide
D. all of these
17. In most food chains,
A. there is less usable energy at the herbivore level than at the carnivore level
B. there are fewer individuals at the top carnivore level than at the second trophic level
C. there are few individuals at the decomposer level
D. there is less usable energy at the producer level than at the carnivore level
18. Of the total amount of energy in the biomass that passes from one trophic level to another in a food chain,
about 90 percent is
A. transpired
B. “burned” in respiration
C. stored in body tissue
The diagram below shows a particular food web. Each letter represents a different species. Arrows indicate the
flow of energy and materials. Use the diagram to answer the next 3 questions (#19-22).
19. Which of the following would most likely have the greatest total biomass?
A. F
B. J
C. K
D. M
E. H
20. Which of the following species is probably a carnivore?
A. J
B. M
C. L
D. G
21. Which of the following species is a decomposer?
A. F
B. G
C. H
D. K
E. L
22. As we go from one level to the next level above it in a typical pyramid of energy,
A. the amount of biomass increases
B. the amount of usable energy increases 10 times
C. the amount of usable energy is about 10 percent of the preceding level
D. the biomass is about the same, but the energy decreases
23. To an ecologist, an “interbreeding group of individuals that occupies a specific geographic area” is a(n)
A. population
B. species
C. community
D. ecosystem
24. Which represents a community?
A. all the same frog species in a pond
B. the abiotic factors in Lake Michigan
C. all the interacting populations in a forest
D. the concentration of minerals in soil
25. A natural community interacting with its abiotic environment is
A. population
B. an organ system
C. an organism
D. an ecosystem
26. Which sequence shows increasing complexity of levels of ecological organization?
A. biosphere, ecosystem, community
B. biosphere, community, ecosystem
C. community, ecosystem, biosphere
D. ecosystem, biosphere, community
27. When two kinds of organisms both use a resource that is in short supply, the usual end result is that
A. both species modify their needs and use some substitute
B. both species survive as long as possible, and then die out
C. one species will win out and eliminate the other
D. the amount of the resource expands to fill the need
E. the two species cooperate and share what is available
Ecology Pre-Test on Part B
1. The carbon dioxide that is released during cell respiration is recycled, and can be used by which
organism(s)?
A. plants
B. animals
C. fungi
D. A and C
E. A, B, and C
2. The oxygen that is released in photosynthesis is recycled, and can be used by which organism(s)?
A. plants
B. animals
C. fungi
D. A and B
E. A,B and C
3. In an ecosystem, energy is
A. lost as heat
C. transferred from level to level
B. recycled
D. all of the above
E. 2 of the above
Match the lettered items in the illustration of the nitrogen cycle with the items below(#4-8).
4.
5.
6.
7.
8.
Nitrogen gas in the atmosphere E
Nitrifying bacteria convert ammonia to nitrites B
Denitrifying bacteria convert nitrates to nitrogen gas (denitrification) D
Ammonification by soil bacteria A
Nitrogen-fixatio AB
Use the following map for Questions #9-15:
9. Large range between night and day temperatures, 25 cm or fewer of rain per year E
10. Little annual change in high temperature and heavy precipitation D
11. Permanently frozen subsoil, short growing season restrict size of plants
A
12. Numerous rootless epiphytes, and tree-dwelling animal species
D
13. Great expanses in all continents, mainly converted to agriculture
AB
14. Many species are nocturnal, escaping the heat in burrows and other cover during daylight hours
E
15. Shedding of leaves by plants and migration or hibernation by animals are common adaptations to cold
C
16. An aquarium in which the only living organisms are algae can be maintained for a longer period of time than an
aquarium in which the only living organisms are protozoa. Which is the best explanation for this?
A. the algae are able to carry on photosynthesis
B. the protozoa do not produce carbon dioxide
C. the protozoa produce carbohydrates
D. the algae are able to live in water
17. An important contributor to the increase in CO2 in the earth’s atmosphere, which may cause a greenhouse
effect, is
A. combustion of fossil fuels, such as coal
B. evaporation of CO2 from the surface of the oceans
C. increased use of CO2 by tropical rain forest trees
D. respiration of all the earth’s living things
E. use of carbon in plastics and other synthetic compounds
18. Which of the following represents the correct order of event in the water cycle?
A. runoff, precipitation, transpiration, plant uptake
B. evaporation, condensation, precipitation, plant uptake, transpiration
C. runoff, groundwater, transpiration, plant uptake
D. condensation, evaporation, plant uptake, precipitation, transpiration
Ecology Pre-Test on Part C
1. The appearance of new kinds of organisms during ecological succession
A. depends upon new kinds of organisms previously inhabiting the community
B. has no relationship to the presence of other organisms
C. affects the kind of organisms that later inhabit the community
D. both A and C are correct
2. Eutrophication in lakes is frequently the direct result of
A. nutrient enrichment
C. a diminished supply of nitrates
B. air pollution
D. decreased light penetration
E. an increase in predators
3. Which of the following statements is false?
A. Increase in the size of a predator population is accompanied by a decrease in the size of the prey
population.
B. No two species can occupy the same ecological niche.
C. Density-dependent limiting factors are not related to number of organisms per given area.
D. The carrying capacity of a given environment may change.
E. If two different species of birds compete for exactly the same food source, one species will
eventually be eliminated.
Answer Choices for Questions #4-7:
A. density-dependent factor
B. density-independent factor
C. J-shaped curve
D. S-shaped (sigmoid) curve
b 4. With the context of population growth, climate is an example.
a 5. Within the context of population growth, competition, parasites, and predators are examples.
c 6. Exponential growth of a population is best represented by this.
d 7. This is the most likely representation of growth in a population. The rate of increase is
exponential, and then changes as the carrying capacity is reached.
8. Primary succession may begin with
A. simple animals
B. bare rock
C. algae
D. small plants
9. The beginning of soil formation from bare rock involves
A. shrubs
B. decomposers
C. lichens
D. both B and C
10. Secondary succession may begin after an
A. forest fire
B. earthquake
C. flood
D. all of these
11. The best description of a climax community is
A. stable and simple
C. changing and complex
B. constantly changing
D. stable and complex
Questions #12-14: The following shows the change over time, in the vegetation of a farmed area
which was left alone for many years.
12. The above diagram illustrates
A. primary succession
B. secondary succession
C. tertiary succession
D. pioneer plants
E. evolution of pine trees
13. The stage which is most likely to be the most stable is
A. the herb community
C. the dense shrub community
B. the shrub community
D. the pine community
E. the fir, birch, white spruce community
14. The most diversity would be expected to be in the
A. the herb community
C. the dense shrub community
B. the shrub community
D. the pine community
E. the fir, birch, white spruce community
15. Biological magnification is
A. the increase in size of organisms at higher trophic levels
B. the increase in number of organisms at higher trophic levels
C. the concentration of stable, nonexcretable chemicals in organisms at higher trophic levels
D. the concentration of nitrates and phosphates in a polluted lake
E. the capture of small organisms by larger organisms at higher trophic levels.
16. DDT has been more of a problem in predatory birds such as the peregrine falcon than in
seed–eating birds. This is because
A. seed–eating birds are smaller
C. DDT is absorbed by animals, but not plants
B. predatory birds are larger
D. the peregrine falcon eats seed-eating birds
Base your answers to the next three questions on the graph below and your knowledge of biology.
The graph represents the relationship between the carrying capacity of the range or grassland that
supports the deer and number of deer actually living on the range, and time (#17-19).
17. In what year was the number of deer living on the range equal to the carrying capacity of the
range?
A. 1905
B. 1915
D. 1920
D. 1930
18. What is the most likely reason why the capacity of the range to support deer decreased
between 1920 and 1930?
A. The deer population became too large.
B. The number of predators increased between 1915 and 1925.
C. The deer population decreased in 1919.
D. An unusually cold winter occurred in 1918.
19. What might be one reason why the number of deer began to increase in 1910?
A. the deer’s natural enemies were killed.
B. The capacity of the range increased.
C. The available vegetation of the area decreased.
D. The winter was longer than normal in 1905.