Name: ________________________ Class: ___________________ Date: __________
ID: B
Biology Chapter 3 Test
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Which of the following descriptions about the organization of an ecosystem is correct?
a. Species make up communities, which make up populations.
b. Species are grouped in populations, which make up communities.
c. Communities make up species, which make up populations.
d. Populations make up species, which make up communities.
____
2. The simplest grouping of more than one kind of organism in the biosphere is a(an)
a. species.
c. community.
b. population.
d. ecosystem.
____
3. Which ecological inquiry method is an ecologist using when he or she enters an area periodically to count the
population numbers of a certain species?
a. modeling
c. observing
b. questioning
d. experimenting
Figure 3-1
____
4. The algae at the beginning of the food chain in Figure 3-1 are
a. heterotrophs.
c. consumers.
b. producers.
d. decomposers.
____
5. An organism that uses energy to produce its own food supply from inorganic compounds is called a(an)
a. detritivore.
c. heterotroph.
b. consumer.
d. autotroph.
____
6. Which of the following organisms does NOT require sunlight to live?
a. chemosynthetic bacteria
c. algae
b. photosynthetic bacteria
d. trees
____
7. The total amount of living tissue within a given trophic level is called the
a. biomass.
c. energy mass.
b. organic mass.
d. trophic mass.
____
8. What animals eat both producers and consumers?
a. omnivores
c.
b. autotrophs
d.
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chemotrophs
herbivores
Name: ________________________
____
ID: B
9. A snake that eats a frog that has eaten an insect that fed on a plant is a
a. first-level producer.
c. second-level producer.
b. first-level consumer.
d. third-level consumer.
Figure 3–2
____ 10. The trophic levels in Figure 3-2 illustrate
a. the amount of living organic matter.
b. the relative amount of energy.
c. that producers outnumber first-level consumers.
d. the relative number of individual organisms.
____ 11. 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
a. used in reproduction.
c. stored as body tissue.
b. stored as fat.
d. eliminated as heat.
____ 12. What is the process by which bacteria convert nitrogen gas in the air to ammonia?
a. decomposition
c. denitrification
b. nitrogen fixation
d. excretion
____ 13. Carbon cycles through the biosphere in all of the following processes EXCEPT
a. respiration.
c. photosynthesis.
b. transpiration.
d. decomposition.
____ 14. The movements of energy and nutrients through living systems are different because
a. nutrients flow in one direction and energy recycles.
b. energy is limited in the biosphere and nutrients are always available.
c. energy forms chemical compounds and nutrients are lost as heat.
d. energy flows in one direction and nutrients recycle.
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Name: ________________________
ID: B
____ 15. Which is most likely to be a limiting nutrient in a freshwater pond?
a. potassium
c. nitrogen
b. phosphorus
d. carbon
Completion
Complete each statement.
16. Autotrophs capture energy from sunlight or ____________________ to produce food.
17. Organisms that break down organic matter and return it to the environment are called
____________________.
Figure 3-1
18. Of the organisms represented in Figure 3-1, the organisms in the oceans with the smallest total biomass are
most likely the ____________________.
19. Water can enter the atmosphere through the processes of evaporation and ____________________.
20. Living organisms require nitrogen to make ____________________, which are used to build proteins.
Short Answer: Answer ONE question for FIVE points. Additional correct answers are worth ONE point extra
credit.
21. Describe the role of algae in ocean food chains.
22. Describe the flow of energy among the following members of an ecosystem: decomposers, autotrophs,
heterotrophs, and the sun.
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Name: ________________________
ID: B
Figure 3–2
23. Describe the flow of energy to the owl in Figure 3-2 if the tree provides 1500 calories of energy to the insects.
24. What is the most likely explanation for why Figure 3-2 shows only one organism at its base? In what way
would an energy diagram be different?
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Name: ________________________
ID: B
Figure 3–3
25. Explain how seepage and transpiration in Figure 3-3 are related.
26. Describe the two sources of energy that fuel life on Earth.
27. How does a food web differ from a food chain?
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Name: ________________________
ID: B
28. Describe the three types of ecological pyramids.
29. Describe the roles of bacteria in the nitrogen cycle.
30. How might a large input of phosphorus affect a freshwater lake over time?
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Name: ________________________
ID: B
Other: Answer ONE question for FIVE points. Additional correct answers are worth ONE point each.
USING SCIENCE SKILLS
Figure 3–4
31. Predicting How might a large omnivore change the flow of energy in Figure 3-4, diagram II?
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Name: ________________________
ID: B
32. Inferring If a limiting nutrient is supplied to the producers in Figure 3-4, diagram II, what effect could it have
on the birds?
33. Interpreting Graphics How many kilocalories (kcal) can the top carnivore in Figure 3-4, diagram I, store?
Explain.
34. Applying Concepts What three scientific approaches do ecologists use to explain complex relationships, such
as in the energy pyramid in Figure 3-4?
35. Applying Concepts Describe how chemosynthesis could contribute to the energy represented by Figure 3-4,
diagram I.
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ID: B
Biology Chapter 3 Test
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
ANS:
ANS:
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ANS:
ANS:
ANS:
ANS:
B
C
C
B
D
A
A
A
D
D
D
B
B
D
B
PTS:
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1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
REF:
REF:
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COMPLETION
16. ANS: chemicals
PTS: 1
17. ANS:
decomposers
detritivores
REF: p. 67
PTS: 1
18. ANS: sharks
REF: p. 69
PTS: 1
REF: p. 72
19. ANS: transpiration
PTS: 1
20. ANS: amino acids
PTS: 1
REF: p. 75
REF: p. 78
1
p. 64
p. 64
p. 65
p. 67
p. 67
p. 68
p. 72
p. 69
p. 70
p. 70
p. 72
p. 78
p. 76 | p. 77
p. 74
p. 80
ID: B
SHORT ANSWER
21. ANS:
The algae are autotrophs, the producers at the base of the food chain.
PTS: 1
REF: p. 67
22. ANS:
Energy flows from the sun to the autotrophs, and from the autotrophs to the heterotrophs. Energy also flows
from the autotrophs and the heterotrophs to the decomposers.
PTS: 1
REF: p. 67 | p. 68 | p. 69
23. ANS:
The insects would provide 10 percent (one tenth) of 1500 calories, or 150 calories, of energy to the shrews.
The shrews would provide one tenth of 150 calories, or 15 calories to the owl.
PTS: 1
REF: p. 72
24. ANS:
The tree at the base has much more available energy than all the insects that live in it. An energy diagram
would be broad at the base like a typical pyramid.
PTS: 1
REF: p. 72
25. ANS:
Water seeps through soil and into the ground water. Roots of trees and plants take the water up through their
roots. Plants release the water through the process of transpiration. Both seepage and transpiration are parts of
the water cycle.
PTS: 1
REF: p. 75
ESSAY
26. ANS:
Sunlight is the main energy source for life on Earth. Less than 3 percent of all the sun’s energy that reaches
Earth is used by living things. Inorganic chemical compounds also provide energy for life on Earth. Plants,
some algae, and certain bacteria can capture energy from sunlight or chemicals and use that energy to produce
food.
PTS: 1
REF: p. 67
27. ANS:
A food chain is a series of steps in which organisms transfer energy by eating and being eaten. A food web is
a feeding relationship among the various organisms in an ecosystem that forms a network of complex
interactions. A food web links together all the food chains in an ecosystem.
PTS: 1
REF: p. 69 | p. 70
28. ANS:
An energy pyramid is a diagram that shows the relative amounts of energy contained within each trophic level
in a food chain or web. A biomass pyramid represents the amount of living tissue within each trophic level. A
pyramid of numbers shows the relative number of organisms at each trophic level.
PTS: 1
REF: p. 72 | p. 73
2
ID: B
29. ANS:
Certain types of bacteria are able to use nitrogen gas directly. These bacteria, which live in the soil and on the
roots of legumes, convert nitrogen gas to ammonia during the process of nitrogen fixation. Other bacteria in
the soil convert ammonia into nitrates and nitrites, which are also taken up directly by producers. Still other
soil bacteria convert nitrates into nitrogen gas during the process of denitrification, returning the nitrogen to
the atmosphere.
PTS: 1
REF: p. 78
30. ANS:
The growth of producers in a water environment like a lake is slowed by lack of a limiting nutrient.
Phosphorus is a limiting nutrient in most freshwater environments. If phosphorus is added in large amounts,
such as from runoff from heavily fertilized fields, an immediate rise in the amount of algae and other
producers can occur. This result is called an algal bloom. If an algal bloom in a lake gets too extensive, it may
cover the surface of the water.
PTS: 1
REF: p. 80
OTHER
31. ANS:
Possible answer: A large omnivore would consume energy at every trophic level, reducing the amount of
energy available to each level above the producers.
PTS: 1
REF: p. 72
32. ANS:
The producers are the bluegrass. Adding a limiting nutrient to the grass would increase the amount of primary
productivity. The result would be an increased amount of biomass at the producer level, and increasing
biomass and available energy at each successive level. The number of birds could increase, because there
would be more for them to eat.
PTS: 1
REF: p. 80
33. ANS:
The bass is the top carnivore. It has 100 kcal available to it from the trophic level below it. The bass will use
part of that energy for its life processes, lose some as heat, and be able to store only about 10 percent, or 10
kcal.
PTS: 1
REF: p. 72
34. ANS:
observing, experimenting, and modeling
PTS: 1
REF: p. 65
35. ANS:
Certain bacteria are chemosynthetic autotrophs and live in tidal marshes along the coast. They are producers
that use inorganic molecules to produce food. The energy they produce would add to the total amount
produced by plants to supply energy to the ecosystem.
PTS: 1
REF: p. 68
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