Name: 
 

CH. 22 Populations and Communities



Modified True/False
Indicate whether the sentence or statement is true or false.  If false, change the identified word or phrase to make the sentence or statement true.
 

1. 

A tapeworm living inside a wolf's body is a predator. _________________________

 

2. 

All of the members of a community belong to the same species. _________________________

 

3. 

Bees and flowers are biotic factors in an ecosystem. _________________________

 

4. 

Individuals decrease the size of a population when they emigrate from it. _________________________

 

5. 

The population density decreases as the number of individuals in an area increases. _________________________

 

6. 

Population size generally increases if the birth rate is greater than the death rate. _________________________

 

7. 

The carrying capacity is the smallest number of individuals in a population that can live in one area. _________________________

 

8. 

An organism's specific role, or how it makes its living, is its habitat. _________________________

 

9. 

In predation, the organism that kills another organism for food is the prey. _________________________

 

10. 

Both species benefit in the type of symbiosis called mutualism. _________________________

 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

11. 

Which of the following is a biotic factor in the prairie ecosystem?
a.
water
b.
sunlight
c.
soil
d.
grass
 

12. 

An organism's habitat must provide all of the following EXCEPT
a.
food.
b.
water.
c.
predators.
d.
shelter.
 

13. 

The nonliving parts of an ecosystem are called
a.
populations.
b.
organisms.
c.
biotic factors.
d.
abiotic factors.
 

14. 

The place where an organism lives and that provides the things the organism needs is called its
a.
habitat.
b.
population.
c.
species.
d.
community.
 

15. 

To carry out photosynthesis, algae and plants use the abiotic factors sunlight, carbon dioxide, and
a.
soil.
b.
salt.
c.
water.
d.
bacteria.
 

16. 

All the different populations that live together in an area make up a(n)
a.
organism.
b.
community.
c.
species.
d.
ecosystem.
 

17. 

The smallest unit of ecological organization is a single
a.
population.
b.
community.
c.
organism.
d.
ecosystem.
 

18. 

The study of how things interact with each other and with their environment is called
a.
ecology.
b.
photosynthesis.
c.
community.
d.
biotic studies.
 

19. 

Which of the following is an example of a population?
a.
the cats and dogs in your neighborhood
b.
the bushes and grass in a park
c.
the rocks in a rock collection
d.
the gray wolves in a forest
 

20. 

Population density is defined as
a.
an approximation of a number, based on reasonable assumptions.
b.
the number of individuals of a population in a specific area.
c.
the number of individuals moving into a population.
d.
the smallest level of ecological organization.
 

21. 

If you count 20 beetles in a garden measuring 5 square meters, the population density of the beetles is
a.
100 beetles per square meter.
b.
20 beetles per square meter.
c.
5 beetles per square meter.
d.
4 beetles per square meter.
 

22. 

Counting the number of organisms in a small area and multiplying to estimate the number in a larger area is called
a.
direct observation.
b.
mark and recapture.
c.
population density.
d.
sampling.
 

23. 

The major way in which new individuals are added to a population is through
a.
sampling.
b.
the birth of offspring.
c.
mark and recapture.
d.
emigration.
 

24. 

A group of antelope leaving the herd in search of better grassland is an example of
a.
immigration.
b.
emigration.
c.
increasing birth rate.
d.
decreasing death rate.
 

25. 

Which term refers to an environmental factor that prevents a population from increasing?
a.
biotic factor
b.
abiotic factor
c.
immigration
d.
limiting factor
 

26. 

The largest population that an environment can support is called its
a.
carrying capacity.
b.
limiting factor.
c.
birth rate.
d.
death rate.
 

27. 

An early winter frost preventing further growth in a tomato garden is an example of
a.
carrying capacity.
b.
a limiting factor.
c.
a biotic factor.
d.
indirect observation.
 

28. 

All of the following are examples of limiting factors EXCEPT
a.
food.
b.
soil.
c.
space.
d.
weather conditions.
 

29. 

An organism's particular role, or how it makes its living, is called its
a.
carrying capacity.
b.
ecosystem.
c.
competition.
d.
niche.
 

30. 

The behaviors and physical characteristics of species that allow them to live successfully in their environment are called
a.
habitats.
b.
limiting factors.
c.
biotic factors.
d.
adaptations.
 

31. 

The struggle between organisms to survive in a habitat with limited resources is called
a.
competition.
b.
predation.
c.
symbiosis.
d.
parasitism.
 

32. 

By hunting at different times of day, the hawk and owl are able to reduce
a.
predation.
b.
competition.
c.
adaptation.
d.
parasitism.
 

33. 

Which of the following describes an interaction in which one organism kills and eats another?
a.
competition
b.
symbiosis
c.
predation
d.
mutualism
 

34. 

Which of the following is an example of a predator adaptation?
a.
a porcupine's needles
b.
a shark's powerful jaws
c.
a frog's bright colors
d.
a plant's poisonous chemicals
 

35. 

When a jellyfish paralyzes a tiny fish with its poisonous tentacles, the fish is the
a.
predator.
b.
prey.
c.
host.
d.
parasite.
 

36. 

A close relationship between two species that benefits at least one of the species is called
a.
natural selection.
b.
symbiosis.
c.
adaptation.
d.
competition.
 

37. 

When a flea is living on a dog, the dog is the
a.
parasite.
b.
host.
c.
predator.
d.
prey.
 

38. 

Mutualism, commensalism, and parasitism are the three types of
a.
symbiotic relationships.
b.
predation.
c.
competition.
d.
prey adaptations.
 

39. 

A hawk building its nest on an arm of the saguaro cactus is an example of
a.
commensalism.
b.
mutualism.
c.
parasitism.
d.
predation.
 

40. 

The Escherichia coli that live in your intestine and help break down food are an example of which type of interaction?
a.
competition.
b.
mutualism.
c.
parasitism.
d.
predation.
 

Completion
Complete each sentence or statement.
 

41. 

The part of an ecosystem where an organism lives and feeds is called the organism's ____________________.
 

 

42. 

All the biotic and abiotic factors in an area together make up a(n) ____________________.
 

 

43. 

Prairie dogs, snakes, and grass make up a level of ecological organization called a(n) ____________________.
 

 

44. 

All the prairie dogs in one area are an example of a(n) ____________________.
 

 

45. 

Water, sunlight, and soil are ____________________ factors in an ecosystem.
 

 

46. 

Two abiotic factors that are needed for photosynthesis are sunlight and ____________________.
 

 

47. 

The study of how living things interact with one another and with their environment is called ____________________.
 

 

48. 

Scientists who study how living things interact with the environment are called ____________________.
 

 

49. 

The ____________________ method of estimating involves multiplying the number of organisms in a small area to find the number in a larger area.
 

 

50. 

Observing animal tracks is an example of ____________________ observation, which is used to estimate population size.
 

 

51. 

A group of zebras breaking off from a herd decreases the size of the herd population through ____________________.
 

 

52. 

The major way that populations increase in size is through the ____________________ of offspring.
 

 

53. 

If food is scarce, it becomes a ____________________ factor that prevents population growth.
 

 

54. 

A lack of places to build nests is an example of ____________________ as a limiting factor for a population of birds.
 

 

55. 

The thick fur of a polar bear is a(n) ____________________ that allows the bear to live successfully in its environment.
 

 

56. 

Ticks feed on the blood of mice in a symbiotic relationship called ____________________.
 

 

57. 

A close relationship between two species that benefits at least one of the species is known as ____________________.
 

 

58. 

The struggle of two species to occupy a certain niche in an ecosystem is an example of ____________________.
 

 

59. 

A hawk building a nest on the arm of a cactus without hurting the cactus is an example of the symbiotic relationship called ____________________.
 

 

60. 

A flea is a parasite that lives on a(n) ____________________ such as a dog.
 

 

Short Answer
 
 
ch-_22_populations__files/i0650000.jpg
 

61. 

Describe two things the prairie dogs need to live that they obtain from their habitat.
 

62. 

What is the smallest unit of organization in an ecosystem? Give two examples from the diagram.
 

63. 

Describe one of the prairie dog's adaptations and how it helps the prairie dog to survive.
 

64. 

What level of ecological organization do all of the owls in a certain area represent?
 

65. 

Is the prairie soil a biotic factor or an abiotic factor? Explain your answer.
 

66. 

Describe three factors that could limit the growth of the prairie dog population.
 
 
ch-_22_populations__files/i0720000.jpg
 

67. 

How was the pheasant population changing at Point A?
 

68. 

Which letter marks the peak of the pheasant population?
 

69. 

What happened to the pheasant population between Point B and Point C?
 

70. 

What are some possible explanations for the change in pheasant population between Point B and Point C?
 

71. 

In 1990, a large resort hotel was built on the island where these pheasants live. Explain how this might have affected the pheasant population.
 

72. 

What was the density of pheasants in 1968, 1976, and 1990?
 

Essay
 

73. 

Explain why two different species in an ecosystem can share the same habitat but not the same niche.
 

74. 

Explain the difference between a population and a community.
 

75. 

Explain the difference between predation and parasitism.
 

76. 

An ecologist counts 75 cardinals in an area measuring 15 square kilometers. What is the population density of the cardinals?
 

77. 

Explain the difference between direct and indirect observation in determining population size.
 

78. 

Define abiotic factor and give four examples.
 

79. 

Explain why the populations of a predator and its prey often follow regular cycles.
 

80. 

Classify these examples of symbiosis by type and explain your choice: 1) Inside a human's intestine live bacteria that make vitamin K; 2) A human picks up bacteria on his or her hands. The bacteria do not cause disease but do feed on the human's dead skin cells; 3) A tick attaches itself to a human and feeds on the human's blood.
 



 
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