1. Ecosystems are organized with populations making up species, which make up communities. 2. The lowest level of environmental complexity that includes living and nonliving factors is the ecosystem. 3. Ecologists study the living world through methods like experimenting and observing.

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EOC ECOLOGY SAMPLE QUESTIONS
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 1. Which of the following descriptions about the organization of an ecosystem is correct?
a. Communities make up species, which make up populations.
b. Populations make up species, which make up communities.
c. Species make up communities, which make up populations.
d. Species make up populations, which make up communities.
_____ 2. The lowest level of environmental complexity that includes living and nonliving factors is
the
a. biome. c. ecosystem.
b. community. d. biosphere.
_____ 3. Which of the following is NOT a basic method used by ecologists to study the living world?
a. experimenting c. modeling
b. animal training d. observing
_____ 4. Plants are
a. primary producers. c. herbivores.
b. primary consumers. d. omnivores.
_____ 5. Compared to land, the open oceans
a. have less zooplankton. c. are nutrient-poor environments.
b. contain unlimited nitrogen. d. are rich in silica and iron.
_____ 6. All the interconnected feeding relationships in an ecosystem make up a food
a. interaction. c. network.
b. chain. d. web.
_____ 7. The total amount of living tissue within a given trophic level is called the
a. organic mass. c. energy mass.
b. trophic mass. d. biomass.
_____ 8. A word that means the same thing as consumer is
a. producer. c. heterotroph.
b. autotroph. d. carbohydrate.
_____ 9. Matter can recycle through the biosphere because
a. matter does not change into new compounds.
b. matter is assembled into chemical compounds.
c. biological systems do not use up matter, they transform it.
d. biological systems use only carbon, oxygen, hydrogen, and nitrogen.

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_____10. What is happening to water at D in Figure 3–1?
a. Water is falling to the ground as precipitation.
b. Water is evaporating from the ocean.
c. Water is being taken up by plants through transpiration.
d. Water is seeping into the ground to become groundwater.
_____11. Nitrogen fixation is carried out primarily by
a. humans. c. bacteria.
b. plants. d. consumers.
_____12. The movements of energy and nutrients through living systems are different because
a. energy flows in one direction, and nutrients recycle.
b. energy is limited in the biosphere, and nutrients are always available.
c. nutrients flow in two directions, and energy recycles.
d. energy forms chemical compounds, and nutrients are lost as heat.
_____13. Animals that get energy by eating the carcasses of other animals that have been killed by
predators or have died of natural causes are called
a. scavengers. c. heterotrophs.
b. omnivores. d. detritivores.
_____14. Each of the following is an abiotic factor in the environment EXCEPT
a. plant life. c. rainfall.
b. soil type. d. temperature.
_____15. The branch of biology dealing with interactions among organisms and between organisms
and their environment is called
a. economy. c. recycling.
b. modeling. d. ecology
16. What events typically contribute to an algal bloom in a lake or ocean?
17. Describe the flow of energy to a third-level consumer if the producers provide 1500 calories of
energy to the first-level consumers.
Figure 3-1

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Using Science Skills
18. Interpret Visuals What is the longest food chain in
Figure 3–5 that contains grass as a producer?
19. Interpret Visuals What are the primary producers in
Figure 3–5?
20. Draw Conclusions Are there any omnivores in Figure 3–5? Explain your answer.
21. Draw Conclusions Which species would be MOST affected if a disease killed off most of the
trees in the ecosystem shown in Figure 3–5? What other species might be affected? Explain your
answers.
22. Apply Concepts Would the snake obtain a greater percentage of energy from the grass after eating
a frog or a grasshopper in Figure 3–5? Explain your answer.
Figure 4-1
_____ 23. Figure 4–1 shows succession in an ecosystem. What organisms are found in the climax
community for this ecosystem?
a. lichens and moss c. weeds and grasses
b. trees and shrubs d. volcanoes and soil
_____ 24. Which biome is characterized by very low temperatures, little precipitation, and permafrost?
a. desert c. tundra
b. temperate forest d. tropical dry forest
Figure 3–5

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_____ 25. The greenhouse effect is
a. something that has only occurred for the last 50 years.
b. a natural phenomenon that maintains Earth’s temperature range.
c. the result of the differences in the angle of the sun’s rays.
d. an unnatural phenomenon that causes heat energy to be radiated back into the
atmosphere.
_____ 26. Which of the following is a biological aspect of an organism’s niche?
a. the water in the area c. the way it gets food
b. amount of sunlight d. composition of soil
_____ 27. Several species of warblers can live in the same spruce tree ONLY because they
a. have different habitats within the tree.
b. don’t eat food from the tree.
c. occupy different niches within the tree.
d. can find different temperatures within the tree.
_____ 28. An interaction in which an animal feeds on plants is called
a. carnivory. c. predation.
b. herbivory. d. symbiosis.
_____ 29. A symbiotic relationship in which both species benefit is
a. commensalism. c. predation.
b. mutualism. d. parasitism.
_____ 30. Primary succession would most likely occur after
a. a forest fire. c. farm land is abandoned.
b. a lava flow. d. a severe storm.
_____ 31. The nutrient availability of aquatic ecosystems is the
a. amount of nitrogen, oxygen, and other elements dissolved in the water.
b. number of other organisms present in the water.
c. amount of rainfall the water receives.
d. number of different animal species living in the water.
_____ 32. Freshwater ecosystems that often originate from underground sources in mountains or hills
are
a. estuaries. c. lakes and ponds.
b. rivers and streams. d. wetlands.
_____ 33. A wetland that contains a mixture of fresh water and salt water is called
a. an estuary. c. a river.
b. a stream. d. a pond.
_____ 34. Which of the following statements is NOT true about the open ocean?
a. The open ocean has low levels of nutrients.
b. Organisms in the deep ocean are exposed to frigid temperatures and total darkness.
c. The open ocean begins at the low-tide mark and extends to the end of the continental
shelf.
d. Most of the photosynthetic activity on Earth occurs in the open ocean within the photic
zone.

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Using Science Skills
Use the diagram below to answer the following questions on the lines provided.
Figure 4–3
Characteristics of Different Biomes
Biome Temperatures Precipitation Soil Quality
Tropical Rain Forest hot year-round wet year-round thin, nutrient-poor
Tropical Dry Forest warm year-round alternating wet and dry
seasons
rich
Tropical Grassland/
Savanna/Shrubland
warm seasonal rainfall compact
Desert variable low precipitation rich in minerals but poor
in organic material
Temperate Grassland warm to hot summers;
cold winters
moderate and seasonal fertile
Temperate Woodland
and Shrubland
hot summers, cool
winters
dry summers; moist
winters
thin, nutrient-poor
Temperate Forest warm summers; cold to
moderate winters
stable year-round fertile
Northwestern
Coniferous Forest
mild temperatures dry summers; abundant
precipitation in the fall,
winter, and spring
rocky, acidic
Boreal Forest short mild summers;
long cold winters
moderate precipitation acidic, nutrient-poor
Tundra short summers; long,
cold, dark winters
low precipitation poorly developed
35. Interpret Tables Which biomes in Figure 4–3 have a relatively stable amount of precipitation all
year long?
36. Analyze Data Which biomes in Figure 4–3 have little variation in temperatures during the year?
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 37. There are 150 Saguaro cactus plants per square kilometer in a certain area of Arizona
desert. To which population characteristic does this information refer?
a. growth rate c. age structure
b. geographic range d. population density
_____ 38. What does the range of a population tell you that density does not?
a. the number that live in an area c. the births per unit area
b. the areas inhabited by a population d. the deaths per unit area

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_____ 39. The movement of organisms into a range is called
a. immigration. c. population shift.
b. emigration. d. carrying capacity.
_____ 40. Which are two ways a population can decrease in size?
a. immigration and emigration
b. increased death rate and immigration
c. decreased birthrate and emigration
d. emigration and increased birthrate
Figure 5–1
_____ 41. The graph in Figure 5–1 shows the growth of a bacterial population. Which of the
following correctly describes the growth curve?
a. logistic c. demographic
b. limiting d. exponential
_____ 42. During some kinds of population growth, the size of each generation of offspring is larger
than the generation before it. So, as the population gets larger, it grows more quickly. This
situation is called
a. logistic growth. c. exponential growth.
b. growth density. d. multiple growth.
_____ 43. The various growth phases through which most populations go are represented on
a. a logistic growth curve. c. a normal curve.
b. an exponential growth curve. d. a population curve.
_____ 44. For most populations that are growing, as resources start to become less available, the
population
a. declines rapidly. c. reaches carrying capacity.
b. increases more rapidly. d. enters a phase of exponential growth.
_____ 45. Sea otters live in the ocean. Which of the following is NOT likely to be a limiting factor
on the sea otter population?
a. disease c. drought
b. competition d. predation

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_____ 46. Which will reduce competition within a species’ population?
a. fewer individuals c. fewer resources
b. higher birthrate d. higher population density
_____ 47. Each of the following is a density-dependent limiting factor EXCEPT
a. competition. c. crowding.
b. temperature. d. disease.
_____ 48. Which of the following is a density-independent limiting factor?
a. earthquake c. emigration
b. disease d. parasitism
_____ 49. Demography is the scientific study of
a. parasitism and disease. c. human populations.
b. modernized countries. d. none of the above
_____ 50. Demographic transition is change from high birthrates and high death rates to
a. exponential growth.
b. low birthrates and low death rates.
c. low birthrates and high death rates.
d. indefinite growth.
_____ 51. Most of the worldwide human population is growing exponentially because
a. human populations have not reached their exponential curve.
b. most countries have not yet completed the demographic transition.
c. human populations do not conform to the logistic model.
d. the food supply is limitless.
Using Science Skills
Use the table below to answer the following questions on the lines provided.
Population Statistics in the United States From 1900 to 1990
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990
Live births per
thousand
32.3 30.1 27.7 21.3 19.4 24.1 23.7 18.4 15.9 15.6
Deaths per thousand 17.1 14.7 13.0 11.3 10.8 9.6 9.5 9.5 8.8 8.7
Number of births
over deaths
15.2 15.4 14.7 10.0 8.6 14.5 14.2 8.9 7.1 6.9
Life expectancy at
birth (yrs)
47.3 50.0 54.1 59.7 62.9 68.2 69.7 70.8 73.7 74.8
Increase in longevity
since 1900 (yrs)
2.7 6.8 12.4 15.6 20.9 22.4 23.5 26.4 27.5
Figure 5–2
52. Interpret Tables According to Figure 5–2, which year had the highest number of live births per
thousand of population?
53. Analyze Data Compare the number of deaths per thousand in 1960 and 1970 as shown in Figure
5–2.

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54. Interpret Tables In which year was the number of births over deaths at its lowest point, according
to Figure 5–2?
55. Draw Conclusions Examine the data in Figure 5–2. Does the number of births over deaths since
1950 increase or decrease?
56. Draw Conclusions How does the life expectancy at birth affect the deaths per thousands? Use
Figure 5–2 to explain your answer.
Short Answer
57. What is a limiting factor? Give three examples.
58. Why is a drought a density-independent limiting factor?
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 59. Imported plants and animals in Hawaii have
a. caused native species to die out.
b. increased the native bird species.
c. improved soil fertility.
d. increased crop yields.
_____ 60. An example of a renewable resource is
a. oil. c. coal.
b. natural gas. d. trees.
_____ 61. When farming, overgrazing, climate change, and/or seasonal drought change farmland into
land that cannot support plant life, it is called
a. desertification. c. deforestation.
b. depletion. d. monoculture.
_____ 62. Farmers can reduce soil erosion by
a. increasing irrigation. c. grazing cattle on the land.
b. contour plowing. d. plowing up roots.
_____ 63. The gray-brown haze often found over large cities is called
a. acid rain. c. particulates.
b. greenhouse gases. d. smog.

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_____ 64. Air and water pollution have been reduced by
a. using fossil fuels in factories. c. raising more cattle for food.
b. using only unleaded gasoline. d. increasing biological magnification.
_____ 65. Which of the terms best describes the number of different species in the biosphere or in a
particular area?
a. biodiversity c. genetic diversity
b. ecosystem diversity d. species diversity
_____ 66. Introduced species can threaten biodiversity because they can
a. cause desertification. c. crowd out native species.
b. cause biological magnification. d. reduce the amount of fertile land.
_____ 67. All of the following are threats to biodiversity EXCEPT
a. biological magnification of toxic compounds.
b. habitat fragmentation.
c. desertification.
d. habitat preservation.
_____ 68. The goals of biodiversity conservation include all of the following EXCEPT
a. protecting individual species.
b. introducing exotic species into new environments.
c. preserving habitats and ecosystems.
d. making sure local people benefit from conservation efforts.
_____ 69. The land and water ecosystems that provide the resources that a person uses and that
neutralize that person’s wastes is part of that person’s
a. biodiversity.
b. ecological footprint.
c. habitat.
d. ecological sustainability.
_____ 70. The data in the graph in Figure 6–1 above
helped ecologists identify which
environmental problem?
a. the hole in the ozone layer
b. global warming
c. habitat fragmentation
d. desertification Figure 6–1

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Using Science Skills
Use the tables below to answer the following questions on the lines provided.
Existing Species and Endangered Organisms
Table I. How Many Species Are
There?
Table II. Organisms Listed as
Endangered in the United States
Groups of
Species
Number Type of Organisms
Number of
Endangered
Species
Plants 250,000 Mammals 63
Roundworms more than 15,000 Birds 78
Mollusks 50,000–200,000 Reptiles 14
Crustaceans 40,000 Amphibians 10
Spiders, mites 75,000 Fishes 70
Insects more than 1,000,000 Snails 20
Vertebrates 60,000 Clams 61
Crustaceans 18
Insects 33
Spiders 12
Flowering plants 565
Conifers 2
Ferns and other plants 24
Figure 6–2
71. Compare and Contrast Which group in Figure 6–2, Table I is the most diverse?
72. Interpret Tables Which group in Figure 6–2, Table II has the most endangered species?
73. Analyze Data Which table in Figure 6–2 tells you about the numbers of species whose population
size is declining in a way that places it in danger of extinction?
74. Predict After 10 years, if conservation efforts to protect entire ecosystems succeed, how would
Table II in Figure 6–2 likely change?
Short Answer
75. Using the systems diagram model, explain how removing the Elwha Dam will support our
sustainability goal in Washington State?