Environmental Science 120

Name:

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

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.

The combined portions of Earth in which all living things exist is called the

a.	biome.	c.	ecosystem.
b.	community.	d.	biosphere.

All of the members of a particular species that live in one area are called a(an)

a.	biome.	c.	community.
b.	population.	d.	ecosystem.

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.	questioning	c.	experimenting
b.	observing	d.	modeling

Figure 3–1

The algae at the beginning of the food chain in Figure 3–1 are

a.	consumers.	c.	producers.
b.	decomposers.	d.	heterotrophs.

Compared to land, the open oceans

a.	are nutrient-rich environments.	c.	are nutrient-poor environments.
b.	contain unlimited nitrogen.	d.	are rich in silica and iron.

Investigating a pond, you note that snails in the pond have thin, weak shells. This is most likely the result of a(an)

a.	ammonia deficiency.	c.	oxygen deficiency.
b.	phosphorus deficiency.	d.	calcium carbonate deficiency.

What is an ecological model of the relationships that form a network of complex interactions among organisms in a community from producers to decomposers?

a.	food web	c.	food chain
b.	an ecosystem	d.	a population

What animals eat both producers and consumers?

a.	herbivores	c.	chemotrophs
b.	omnivores	d.	autotrophs

10.

What is the term for each step in the transfer of energy and matter within a food web?

a.	energy path	c.	trophic level
b.	food chain	d.	food pyramid

11.

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

12.

The trophic levels in Figure 3–2 illustrate

a.	the relative amount of energy at each level.
b.	the amount of living organic matter at each level.
c.	the relative number of individual organisms at each level.
d.	that the producers outnumber first-level consumers.

13.

In which way does Figure 3–2 differ from a typical model of trophic levels?

a.	Second-level consumers outnumber first-level consumers.
b.	Third-level consumers outnumber second-level consumers.
c.	First-level consumers outnumber producers.
d.	First-level consumers outnumber second-level consumers.

14.

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 fat.
b.	stored as body tissue.	d.	eliminated as heat.

15.

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.

16.

Matter can recycle through the biosphere because

a.	matter is passed out of the body as waste.
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.

17.

The repeated movement of water between Earth’s surface and the atmosphere is called

a.	the water cycle.	c.	precipitation.
b.	the condensation cycle.	d.	evaporation.

18.

What is the process by which bacteria convert nitrogen gas in the air to ammonia?

a.	nitrogen fixation	c.	decomposition
b.	excretion	d.	denitrification

19.

How is carbon stored in the biosphere?

a.	in the atmosphere as carbon dioxide
b.	underground as fossil fuels and calcium carbonate rock
c.	in the oceans as dissolved carbon dioxide
d.	all of the above

20.

What can happen after a lake receives a large input of a limiting nutrient?

a.	An algal bloom occurs.
b.	Algae begin to die and decomposers take over.
c.	Nitrogen compounds are recycled.
d.	The concentration of oxygen drops below the necessary level.

21.

If a nutrient is in such short supply in an ecosystem that it affects an animal’s growth, the

a.	animal becomes a decomposer.	c.	nutrient leaves the food chain.
b.	substance is a limiting nutrient.	d.	ecosystem will not survive.

22.

The loss of heat to space is slowed by

a.	radiation entering the atmosphere.	c.	solar energy.
b.	atmospheric gases.	d.	the biosphere.

23.

The greenhouse effect is

a.	the result of an excess of carbon dioxide in the atmosphere.
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.

24.

Earth has three main climate zones because of the differences in latitude and, thus,

a.	amount of precipitation received.	c.	ocean currents.
b.	angle of heating.	d.	prevailing winds.

25.

Each of the following is an abiotic factor in the environment EXCEPT

a.	plant life.	c.	rainfall.
b.	soil type.	d.	temperature.

26.

Which is a biotic factor that affects the size of a population in a specific ecosystem?

a.	average temperature of the ecosystem
b.	type of soil in the ecosystem
c.	number and kinds of predators in the ecosystem
d.	concentration of oxygen in the ecosystem

27.

Several species of warblers can live in the same spruce tree ONLY because they

a.	have different habitats within the tree.
b.	eat different foods within the tree.
c.	occupy different niches within the tree.
d.	can find different temperatures within the tree.

28.

A wolf pack hunts, kills, and feeds on a moose. In this interaction, the wolves are

a.	hosts.	c.	mutualists.
b.	prey.	d.	predators.

29.

Different species can share the same habitat, but competition among them is reduced if they

a.	reproduce at different times.	c.	increase their populations.
b.	eat less.	d.	occupy different niches.

30.

No two species can occupy the same niche in the same habitat at the same time

a.	because of the interactions that shape the ecosystem.
b.	unless the species require different abiotic factors.
c.	because of the competitive exclusion principle.
d.	unless the species require different biotic factors.

31.

The symbiotic relationship between a flower and the insect that feeds on its nectar is an example of

a.	mutualism because the flower provides the insect with food and the insect pollinates the flower.
b.	parasitism because the insect lives off the nectar from the flower.
c.	commensalism because the insect does not harm the flower and the flower does not benefit from the relationship.
d.	predation because the insect feeds on the flower.

32.

Which factor(s) can influence continual change in an ecosystem?

a.	further disturbances	c.	introduction of nonnative species
b.	long-term climate changes	d.	all of the above

33.

Climate conditions in a small area that differ significantly from the climate of the surrounding area are called

a.	natural features.	c.	biomes.
b.	microclimates.	d.	ecosystems.

34.

Which biome is characterized by very low temperatures, little precipitation, and permafrost?

a.	desert	c.	tundra
b.	temperate forest	d.	tropical dry forest

35.

Ponds and lakes are

a.	flowing-water ecosystems.	c.	standing-water ecosystems.
b.	wetlands.	d.	estuaries.

36.

Which is NOT an adaptation that organisms have for living in flowing water?

a.	hooks	c.	streamlined bodies
b.	tentacles	d.	suckers

37.

Which is one way a wetland ecosystem differs from a standing-water ecosystem?

a.	Water circulates in a standing-water ecosystem but not in a wetland.
b.	Wetlands are nesting areas for birds, but standing-water ecosystems are not.
c.	Water does not always cover a wetland as it does a standing-water ecosystem.
d.	Wetlands are salty, but standing-water ecosystems are fresh.

38.

Which organism lives where it is sometimes submerged and routinely exposed to air, heat, battering waves, and strong currents?

a.	sea star	c.	dolphin
b.	tube worm	d.	whale

39.

Which of the following is NOT one of the factors that play a role in population growth rate?

a.	immigration	c.	emigration
b.	death rate	d.	demography

40.

Sea otters are important to the populations of

a.	kelp.	c.	killer whales.
b.	sea urchins.	d.	all of the above

41.

A small farming community in Texas covers 14 square kilometers. There are 420 individuals who live within the town limits. What is the population density of this community?

a.	0.03 individuals per square kilometer
b.	53 individuals per square kilometer
c.	30 individuals per square kilometer
d.	10.24 individuals per square kilometer

42.

The movement of organisms into a given area from another area is called

a.	immigration.	c.	population shift.
b.	emigration.	d.	carrying capacity.

43.

When organisms move out of the population, this is known as

a.	emigration.	c.	immigration.
b.	abandonment.	d.	succession.

44.

What must occur in a population for it to grow?

a.	The birthrate becomes higher than the death rate.
b.	The birthrate stays the same and the death rate increases.
c.	The birthrate becomes lower than the death rate.
d.	The birthrate and the death rate remain the same.

45.

What is happening in a population as it decreases?

a.	The birthrate and the death rate remain the same.
b.	The death rate becomes lower than the birthrate.
c.	The death rate stays the same and the birthrate increases.
d.	The death rate becomes higher than the birthrate.

46.

If immigration and emigration numbers remain equal, which is the most important contributing factor to a slowed growth rate?

a.	increased birthrate	c.	decreased birthrate
b.	constant death rate	d.	constant birthrate

47.

Which are two ways a population can decrease in size?

a.	immigration and emigration	c.	decreased birthrate and emigration
b.	increased death rate and immigration	d.	emigration and increased birthrate

48.

When individuals in a population reproduce at a constant rate, it is called

a.	logistic growth.	c.	exponential growth.
b.	growth density.	d.	multiple growth.

49.

As resources in a population become less available, the population

a.	declines rapidly.	c.	reaches carrying capacity.
b.	increases slowly.	d.	enters a phase of exponential growth.

50.

When the exponential phase of a logistic growth curve of a population ceases,

a.	the size of the population drops.
b.	the size of the population stays the same.
c.	population growth begins to slow down.
d.	population growth begins to speed up.

51.

All of the following are limiting factors EXCEPT

a.	immigration.	c.	predation.
b.	competition.	d.	human disturbances.

52.

Which will reduce competition within a species’ population?

a.	fewer individuals	c.	fewer resources
b.	higher birthrate	d.	higher population density

53.

A limiting nutrient is to ecosystem productivity as a limiting factor is to population

a.	birthrate.	c.	growth rate.
b.	density.	d.	immigration.

54.

Which would be least likely to be affected by a density-dependent limiting factor?

a.	a small, scattered population
b.	a population with a high birthrate
c.	a large, dense population
d.	a population with a high immigration rate

55.

Which of the following would NOT be a limiting factor related to population density?

a.	a struggle for food, water, space, or sunlight
b.	predator/prey relationships
c.	the eruption of a volcano
d.	parasitism and disease

56.

About 500 years ago, the world’s population started

a.	decreasing.	c.	growing more rapidly.
b.	to reach carrying capacity.	d.	to level off.

57.

Countries in the first stage of demographic transition have

a.	a low death rate and a high birthrate.	c.	a slowly growing population.
b.	a high death rate and a low birthrate.	d.	more old people than young people.

58.

Demographic transition begins with changes in society that

a.	lower the birthrate.	c.	lower the death rate.
b.	increase the birthrate.	d.	increase the death rate.

59.

Which country has not yet completed the demographic transition?

a.	United States	c.	Great Britain
b.	India	d.	Japan

60.

The anticipated human population by the year 2050 is about

a.	7.8 billion.	c.	9 trillion.
b.	9 billion.	d.	78 billion.

61.

In Rwanda, there are more young children than teenagers, and more teenagers than adults. This age structure indicates a population that

a.	has stopped growing.	c.	has a steady growth rate.
b.	will double in 30 years.	d.	will decrease in 30 years.

62.

In countries like India, the human population is growing

a.	exponentially.	c.	logistically.
b.	transitionally.	d.	demographically.

63.

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.

64.

How can a diagram of a population’s age structure predict how it can grow?

a.	It shows how many people are at reproductive ages.
b.	It shows how many people will probably die within a few years.
c.	It shows how many people are entering the population by birth.
d.	all of the above

65.

In the very distant past, most people

a.	lived in small groups.	c.	did not gather plants.
b.	lived in permanent settlements.	d.	did not hunt animals.

66.

The Americans, Europeans, and Asians who settled in the islands of Hawaii changed the islands by

a.	clearing vast areas for the growth of sugar cane.
b.	using large amounts of water.
c.	introducing nonnative crop plants.
d.	all of the above

67.

An environmental problem that resulted from the green revolution was

a.	overpopulation.	c.	starvation.
b.	failed crops.	d.	depleted water supplies.

68.

Land is a resource that provides

a.	space for cities and suburbs.	c.	soil for growing crops.
b.	raw materials for industry.	d.	all of the above

69.

An old-growth forest is

a.	a renewable resource.	c.	a microclimate.
b.	a nonrenewable resource.	d.	poor in biodiversity.

70.

Why are fossil fuels nonrenewable?

a.	They require hundreds of millions of years to form.
b.	Their ecosystems change forever when they are burned.
c.	They are converted to carbon dioxide when they are burned.
d.	They exist in a very small supply.

71.

Using renewable resources while ensuring that they are not depleted is a practice called

a.	sustainable development.	c.	biological magnification.
b.	monoculture.	d.	subsistence hunting.

72.

An example of a sustainable-development practice is the use of beneficial insects like ladybugs to

a.	harm natural resources.	c.	control unwanted pests.
b.	pollinate plants.	d.	eat unwanted plants.

73.

The sulfur and nitrogen compounds in smog combine with water to form

a.	ozone.	c.	acid rain.
b.	ammonia.	d.	chlorofluorocarbons.

74.

Farmers can reduce soil erosion by

a.	increasing irrigation.	c.	grazing cattle on the land.
b.	contour plowing.	d.	plowing up roots.

75.

Which is a way to limit deforestation?

a.	use more wood products	c.	increase carbon dioxide levels
b.	plant and harvest trees on tree farms	d.	fertilize the soil

76.

The number of different species in the biosphere is called

a.	biodiversity.	c.	genetic diversity.
b.	ecosystem diversity.	d.	species diversity.

77.

Biodiversity is important to human society because it

a.	is a natural resource.	c.	provides medicines.
b.	provides food and goods.	d.	all of the above

78.

How are species diversity and genetic diversity different?

a.	Species diversity is counted only in ecosystems, while genetic diversity is counted through the entire biosphere.
b.	Species diversity measures the number of species in the biosphere, while genetic diversity measures the variety of genes in the biosphere, including genetic variation within species.
c.	Species diversity measures the number of individuals of a species, while genetic diversity measures the total variety of species.
d.	Conservation biology is concerned with species diversity, but not with genetic diversity.

79.

Biodiversity is valuable in the biosphere because it

a.	gives us interesting things to look at.
b.	tells us about many other species.
c.	is the biological life-support system of our planet.
d.	provides humans with resistance to disease.

80.

Human well-being is tied to biodiversity because

a.	humans love to look at beautiful things.
b.	humans are part of the food webs and energy cycles that a great variety of organisms share.
c.	less biodiversity makes humans vulnerable to extinction.
d.	humans need a wide variety of animal species for hunting and wildlife products.

81.

One property that makes DDT hazardous over the long run is that DDT is

a.	an insecticide.	c.	nonbiodegradable.
b.	a perfect pesticide.	d.	deadly to herbivores.

82.

One of the greatest threats today to biological diversity is

a.	old-growth forests.	c.	habitat destruction.
b.	ozone depletion.	d.	monoculture.

83.

As DDT moves up the trophic levels in food chains, or food webs, its concentration

a.	stays the same.	c.	decreases.
b.	increases.	d.	is eliminated.

84.

An ecological “hot spot” is an area where

a.	habitats and species are healthy.
b.	hunting is encouraged.
c.	diverse habitats and species are at high risk of extinction.
d.	species diversity is too high.

85.

The goals of conservation biology include all of the following EXCEPT

a.	wise management of natural resources.
b.	introducing foreign species into new environments.
c.	preservation of habitats and wildlife.
d.	protection of biodiversity.

86.

The “hot spot” strategy seeks to protect species in danger of extinction due to

a.	captive breeding programs.	c.	human activity.
b.	expanding national parks.	d.	all of the above

87.

Protecting an entire ecosystem will ensure that

a.	captive breeding programs will succeed.
b.	existing parks and reserves will expand.
c.	governments will set aside land.
d.	natural habitats and the interactions of many different species will be preserved.

88.

Some scientists think that global warming may be

a.	a natural variation in climate.	c.	melting the polar ice caps.
b.	a result of human activities.	d.	all of the above

89.

What would be the most likely effect of an increase in the use of CFCs?

a.	The ozone layer would suddenly disappear.
b.	The ozone holes would get smaller.
c.	The ozone holes would get larger.
d.	There would be no effect on ozone in the atmosphere.

90.

Carbon dioxide is released into the atmosphere by all of the following EXCEPT the

a.	burning of fossil fuels.	c.	burning of trees and forests.
b.	depletion of the ozone layer.	d.	burning of gasoline

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

91.

Ecologists use tools such as binoculars and microscopes to model changes in the environment. _________________________

92.

In an ecological pyramid, the biomass of organisms increases at each successive level. _________________________

93.

Only about 10 percent of the energy in a trophic level is available to organisms at the next trophic level. _________________________

94.

Carbon dioxide is essential to ecosystem productivity because it is used by plants during photosynethsis. _________________________

95.

Scientists classify the nitrogen, carbon, and water cycles as biogeochemical cycles. _________________________

96.

Aquatic ecosystems can receive a large input of a limiting nutrient from the runoff from heavily fertilized fields. _________________________

97.

Earth’s natural “insulating blanket” is the biosphere. _________________________

98.

Weather is the average, year-after-year conditions of temperature and precipitation in a particular region. ____________________

99.

Carbon dioxide, methane, and water vapor trap light energy. _________________________

100.

The tropical rain forest is characterized by a wet season and a dry season. _________________________

101.

As a flowing-water ecosystem travels downhill from its origin, the water flow typically changes from a turbulent current to slow meanders. _________________________

102.

There are about four million births per year in the United States. This statistic is a population dynamic called growth rate. _________________________

103.

Logistic growth occurs when a population’s growth slows or stops, following a period of rapid growth. _________________________

104.

The exponential model of population growth accounts for the influence of carrying capacity. _________________________

105.

One of the best-known mechanisms of population control is the parasite-host relationship. _________________________

106.

Predators can limit the size of populations by weakening their hosts, resulting in disease or death. _________________________

107.

Human activities, such as damming rivers, are density-independent limiting factors. _________________________

108.

Resource shortages triggered by increasing population size are density-independent limiting factors. _________________________

109.

The human population grew slowly from the beginning of human existence, and then began to grow exponentially about 200 years ago. _________________________

110.

The population of a country whose age structure has many more children than people over 40 years of age will probably decrease rapidly in the future. _________________________

111.

An indication that a country has completed the demographic transition is a low birthrate and a low death rate. _________________________

112.

The intensive farming practices of the green revolution led to the use of beneficial insecticides. _________________________

113.

By the end of the last ice age, humans began the practice of agriculture. _________________________

114.

According to the principles of conservation biology, a sustainable system is efficient when it consumes as little energy and material as possible. ______________________________

115.

Acidic gases are released into the air by combustion processes such as the burning of fossil fuels. _________________________

116.

One of the values of biological magnification is its potential as a source for material that is beneficial to humankind. _________________________

117.

Biodiversity is important to humankind because we are part of it and dependent on it for our own survival. _________________________

118.

An introduced species can drive an invasive species to extinction. _________________________

119.

Conservation goals must be weighed against economic costs. _________________________

120.

A result of global warming might be a rise in sea level. _________________________

Completion
Complete each statement.

121.

The study of interactions among organisms and between organisms and their physical surroundings is called ____________________.

Figure 3–3

122.

Ecologists make ____________________ to study large-scale phenomena, such as Earth’s water cycle shown in Figure 3–3.

123.

The water shown flowing over land in Figure 3–3 is called ____________________.

124.

Organisms that break down organic matter and return it to the environment are called ____________________.

125.

In a four-level energy pyramid, if the first level contains 500 calories of energy, the third level will contain approximately ____________________ calories.

126.

Phosphorus is a key ingredient of ____________________ because farmers know that it forms part of the energy-producing molecules that plants require in order to grow.

127.

Average year-after-year conditions are to climate as day-to-day atmospheric conditions are to _________________.

128.

Atmospheric gases that trap heat inside Earth’s atmosphere are called ____________________ gases.

Figure 4–1

129.

According to Figure 4–1, the north polar zone lies above ____________________ latitude.

130.

An abiotic factor that is used to determine climate but not to categorize aquatic ecosystems is ____________________.

131.

If an entire wolf population dies, the moose population on which it preys will grow to the environment’s ____________________.

132.

The change in growth rate that results from the change in birthrates and death rates is known as a ______________________________.

133.

To prevent certain fish populations from collapsing, certain ____________________ have been temporarily closed.

134.

Microscopic particles, such as dust and ash, that can enter the nose, mouth, and lungs are called ____________________.

135.

Any species that is threatened with extinction is a(an) ____________________ species.

136.

Excessive levels of DDT in a small algae-eating fish is an example of ______________________________.

137.

Top-level carnivores are at greatest risk from ______________________________ because they have the highest concentration of toxic compounds in their tissues.

138.

Zoos have established _________________________ programs, in which young animals are raised in protected surroundings until the population is stable and are later returned to the wild.

139.

Conservation biology integrates information from other scientific disciplines, such as ____________________, geography, and natural resource management.

140.

The ____________________ acts as Earth’s sunscreen.