Unit 2 Test Review
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. The branch of biology dealing with interactions among organisms and between organisms and their
environment is called
Figure 3–4
2. Give an example of a food chain in the food web shown in Figure 3–4?
3. The lowest level of environmental complexity that includes living and nonliving factors is the
a. community.
c. biosphere.
b. biome.
d. ecosystem.
4. Organisms that obtain nutrients by breaking down dead and decaying plants and animals are called
5. What is at the base of all ecological pyramids?
6. 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. geographic distribution
c. age structure
b. population density
d. growth rate
7. Polar bears live in the arctic. The arctic is their
Figure 3–3
8. What is happening to water at D in Figure 3–3?
Figure 4–1
9. What would happen if the population of the bird species shown in the ecosystem in Figure 4–1 were
to suddenly decrease?
10. The goals of conservation biology include
11. Which is a biotic factor that affects the size of a population in a specific ecosystem?
a. number and kinds of predators in the ecosystem
b. average temperature of the ecosystem
c. type of soil in the ecosystem
d. concentration of oxygen in the ecosystem
12. An example of a renewable resource is
13. Which are two ways a population can decrease in size?
14. Demographic transition is change from high birthrates and high death rates to
15. All of the following are threats to biodiversity EXCEPT
a. habitat fragmentation.
b. species preservation.
c. biological magnification of toxic compounds.
d. invasive species.
16. Which of the following is NOT recycled in the biosphere?
a. carbon
c. water
b. nitrogen
d. energy
17. The sum total of the genetically based variety of living organisms in the biosphere is called
18. As resources in a population become less available, the population
a. reaches carrying capacity.
c. increases slowly.
b. enters a phase of exponential
d. declines rapidly.
growth.
19. The symbiotic relationship between a flower and the insect that feeds on its nectar is an
example of
20. The combined portions of Earth in which all living things exist is called the
21. How does an area’s weather differ from the area’s climate?
22. How is carbon stored in the biosphere?
Figure 6–5
23. The data in the graph in Figure 6–5 above helped ecologists identify which environmental problem?
a. the hole in the ozone layer
b. global warming
c. habitat fragmentation
d. desertification
24. An organism that uses energy to produce its own food supply from inorganic compounds is
called a(an)
25. Demography is the scientific study of
26. Introduced species can threaten biodiversity because they can
27. Which of the following is true about nonrenewable resources?
a. Using them up will help keep the environment healthy.
b. There are plenty for people to use for a very long time.
c. They can be replaced through sustainable development.
d. They cannot be replaced after they are used up.
28. Which of the following gives you information about a population’s age structure?
a. Individuals live in rain forests in tropical South America.
b. There are 25 individuals with a square kilometer.
c. There are 10 males and 15 females under the age of two.
d. All individuals are found at least 10 meters away from others.
29. The chemistry of aquatic ecosystems is determined by the
30. The human population experienced exponential growth after
a. plowing and irrigation began.
c. agriculture began.
b. the Industrial Revolution began.
d. the bubonic plague began.
31. What is the term for each step in the transfer of energy and matter within a food web?
32. A biome is identified by its particular set of abiotic factors and its
a. specific geographical location.
b. characteristic ecological community.
c. distance from the equator.
d. average precipitation and temperature.
33. How is parasitism different from commensalism?
Figure 3–2
34. What goes in Box 5 of the food web in Figure 3–2?
35. When organisms move out of the population, this is known as
36. Overexposure to UV radiation can
37. Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of
the remaining energy, some is used for the organism’s life processes, and the rest is
38. Primary succession can begin after
a. a lava flow.
b. farm land is abandoned.
c. a severe storm.
d. a forest fire.
39. Earth has three main climate zones because of the differences in latitude and, thus,
a. ocean currents.
c. angle of heating.
b. prevailing winds.
d. amount of precipitation received.
40.What is one difference between primary and secondary succession?
41. Which of the following graphs is a graph showing exponential growth?
a.
c.
b.
d.
42. What is the original source of almost all the energy in most ecosystems?
43. A mountain can affect climate by
a. causing precipitation to fall mostly on one side of the mountain.
b. interfering with air currents and affecting Earth’s rotation.
c. absorbing more solar energy at the peak than at the base of the mountain.
d. pushing a cool air mass back out over the ocean.
44. An organism’s niche is
45. One of the greatest threats today to biological diversity is
a. monoculture.
c. old-growth forests.
b. ozone depletion.
d. habitat destruction.
46. Which of the following descriptions about the organization of an ecosystem is correct?
a. Populations make up species, which make up communities.
b. Species make up communities, which make up populations.
c. Species make up populations, which make up communities.
d. Communities make up species, which make up populations.
47. The number of different species in the biosphere or in a particular area is called
48.When erosion and other factors cause soil to lose its ability to hold water and other nutrients and to
support plant life, it is called
49. Which of the following is a density-independent limiting factor?
a. a struggle for food, water, space, or sunlight
b. the eruption of a volcano
c. predator/prey relationships
d. parasitism and disease
50. Ideally, sustainable development should
51. Temperatures on Earth remain within a suitable range for life as we know it because of the
a. loss of heat to space.
b. radiation of sunlight back into the atmosphere.
c. unequal heating of Earth’s surface.
d. greenhouse effect.
52. Why is an organism’s niche like a person’s occupation?
53. Most of the energy available to a consumer trophic level is used by organisms for
a. transfer to the next trophic level.
b. respiration, movement, and reproduction.
c. producing inorganic chemical compounds.
d. performing photosynthesis.
54. A snake that eats a frog that has eaten an insect that fed on a plant is a
a. second-level producer.
c. first-level producer.
b. third-level consumer.
d. first-level consumer.
55. As DDT moves up the trophic levels in food chains or food webs its concentration
56. Aquatic ecosystems are classified by all of the following EXCEPT
a. depth and flow of the water.
c. organisms that live there.
b. temperature of the water.
d. chemistry of the water.
57. A developer wants to build new a new housing development in or around a large city. Which of the
following plans would be LEAST harmful to the environment?
a. Filling a wetland area and building oceanfront condominiums.
b. Building apartments at the site of an abandoned factory in the city.
c. Building a neighborhood in a meadow at the edge of the city.
d. Clearing a forested area outside of the city to build houses.
58. Different species can share the same habitat, but competition among them is reduced if they
a. eat less.
c. occupy different niches.
b. increase their populations.
d. reproduce at different times.
59. The anticipated human population by the year 2050 is about
60. A wolf pack hunts, kills, and feeds on a moose. In this interaction, the wolves are
61. Something that controls the growth or size of a population is
a. the carrying capacity.
b. a limiting factor.
c. the growth rate.
d. a growth factor.
62. Carbon dioxide is released into the atmosphere by
63. What factors contribute to Earth’s climate
64. Which is an example of how biotic and abiotic factors interact?
a. Tree roots split apart rocks in the ground.
b. Humidity in the air forms fog in a valley.
c. Water and soil mix together to make mud.
d. Sunlight increases the temperature of pond water.
Figure 6–2
65. The green revolution has doubled food production over the last 50 years. Starting in 1965, in what
year did the amount of chemical fertilizers used worldwide double, according to Figure 6–2?
Figure 3–4
66. Figure 3–4 shows a food web arranged into trophic levels. How many energy-transferring steps
away from the sun is the deer?
67. The movements of energy and nutrients through living systems are different because
a. nutrients flow in one direction, and energy recycles.
b. energy flows in one direction, and nutrients recycle.
c. energy is limited in the biosphere, and nutrients are always available.
d. energy forms chemical compounds, and nutrients are lost as heat.
68. A disease resulting in the deaths of one third of a dense population of bats in a cave would be a
69. A bird stalks, kills, and then eats an insect. Based on its behavior, which ecological terms describe
the bird?
a. carnivore, consumer
c. producer, heterotroph
b. autotroph, herbivore
d. herbivore, decomposer