Deck 23: Ecosystems and Populations

Question 1

A scientist is studying the flow of energy into and out of a rain forest as well as the usage of energy by the organisms that inhabit that area. This study would be at the level of a(n)

A) population.
B) biosphere.
C) community.
D) species.
E) ecosystem.

Answer 1

E

Question 2

In a graphical representation of an organism's population growth in a given habitat, the growth rate for an organism whose population is increasing according to its biotic potential is best represented by a(n)

A) line with a negative slope.
B) S-shaped curve.
C) flat line (no slope) set at the carrying capacity of the environment.
D) exponential growth curve.
E) flat line (no slope) set at the equilibrium point of environmental resistance versus biotic growth potential.

Answer 2

D

Question 3

Which one of the following statements accurately reflects the nature of mature communities?

A) Mature communities have more consumers than producers, because the producers are so efficient.
B) Mature communities develop very quickly.
C) Succession begins once a mature community has been established.
D) Mature communities are so well established that when disturbed, they quickly recover.
E) Mature communities are the most efficient in terms of energy utilization and exhibit the greatest species diversity.

Answer 3

E

Question 4

Regular, consistent intervention, such as some modern logging practices, may create which type of stable community?

A) immature
B) evergreen
C) forest
D) recovered
E) varied

Question 5

Organisms that feed on detritus are known as

A) omnivores.
B) primary consumers.
C) herbivores.
D) decomposers.
E) autotrophs.

Question 6

A species' biotic potential is intrinsically determined by all of the following EXCEPT which one?

A) the number of members of reproductive age
B) the number of offspring produced by each reproducing member
C) the time span before offspring reach reproductive maturity
D) the ratio of males to females
E) the presence of competing species in the same habitat

Question 7

Population sizes begin to stabilize near the carrying capacity when

A) zero population is achieved.
B) the number of species in the environment begins to decrease.
C) environmental resistance begins to limit the population's biotic potential.
D) the replacement fertility rate reaches 2.1.
E) a population's biotic potential becomes unlimited.

Question 8

The total living component of an ecosystem is its

A) niche.
B) biotic potential.
C) carrying capacity.
D) biomass.
E) geographic range.

Question 9

Herbivores may also be referred to as

A) producers.
B) quaternary consumers.
C) primary consumers.
D) carbohydrate consumers.
E) autotrophs.

Question 10

Approximately ________% of the stored energy of an organism at one level of a food web is transferred to the tissues of the organism that consumes it at the next level of the food web.

A) 1
B) 10
C) 25
D) 50
E) 100

Question 11

Which one of the following is TRUE regarding the flow of energy through an ecosystem?

A) Energy flows from the sun to consumers and then to producers.
B) Energy flows in multiple directions through an ecosystem.
C) Energy is cycled through an ecosystem and rarely lost as heat.
D) Energy flows from the sun to producers and then to consumers.
E) As energy flows through an ecosystem, it does not change form.

Question 12

Omnivores differ from carnivores in that omnivores derive their energy from

A) green plants.
B) plants and animals.
C) detritus.
D) animals only.
E) plants, animals, and photosynthesis.

Question 13

Populations of species that occupy the same geographic area and interact with each other are collectively called a(n)

A) population.
B) ecosystem.
C) drift.
D) biosphere.
E) community.

Question 14

If an owl is moved from a mature evergreen forest to a mature hedgerow in a suburban neighborhood, the owl's ________ has been changed.

A) biosphere
B) habitat
C) range
D) environmental resistance
E) niche

Question 15

The population of a particular species that an ecosystem can sustain indefinitely is called its

A) climax community.
B) growth rate.
C) carrying capacity.
D) environmental range.
E) habitat distribution.

Question 16

Succession leads to the establishment of a(n)

A) community that consists of only one or two dominant species.
B) mature community.
C) ecosystem.
D) community that has a limited number of natural resources.
E) community that is inefficient in terms of its use of energy and nutrients.

Question 17

During photosynthesis, high-energy carbohydrates are produced at the end of

A) light absorption by chlorophyll.
B) cellular respiration.
C) the light reactions.
D) the Calvin cycle.
E) the electron transport pathway.

Question 18

All of the red squirrels living on a college campus would be a(n)

A) genus.
B) family.
C) population.
D) ecosystem.
E) community.

Question 19

Woodpeckers, insects, bacteria, hawks, and raccoons are found to reside in the same forest. Studies of the interactions between these organisms would be at the level of a

A) community.
B) species.
C) biosphere.
D) population.
E) niche.

Question 20

Trees undergoing photosynthesis in a mature forest can best be described as

A) primary consumers.
B) secondary consumers.
C) chemoautotrophs.
D) primary producers.
E) heterotrophs.

Question 21

The rapid growth of the human population still seen today began in the

A) 1200s.
B) 1400s.
C) 1700s.
D) 1800s.
E) 1900s.

Question 22

Human population began to rise rapidly following the

A) Industrial Revolution.
B) end of World War I.
C) period known as the Black Death.
D) end of the 20th century.
E) end of the Ice Age.

Question 23

The average fertility rate required to achieve long-term zero population growth is referred to as the

A) fertility rate.
B) fertility growth rate.
C) human carrying capacity.
D) stabilization fertility rate.
E) replacement fertility rate.

Question 24

The figure above shows an ecological pyramid. Which level of this pyramid contains the primary producers?

A) A
B) B
C) C
D) D
E) C and D

Question 25

Most precipitation reaching land results from

A) evaporation of surface water over land.
B) upwelling of freshwater.
C) atmospheric synthesis of water.
D) evaporation of water from oceans.
E) evaporation of water from plants during photosynthesis.

Question 26

Under natural conditions, the amount of nitrogen gas returned to the atmosphere by denitrification approximately equals

A) phosphorus cycling.
B) evaporation.
C) nitrogen fixation.
D) sublimation.
E) photosynthesis.

Question 27

Which one of the following is TRUE regarding an ecological pyramid?

A) An ecological pyramid can depict either the total amount of energy stored at each level of an ecosystem or the total biomass at each level.
B) The population of producers depends largely on the populations of consumers below it.
C) The amount of energy represented by tertiary consumers is greater than the amount of energy represented by primary consumers.
D) Animals such as wolves and eagles would be located at the base of the pyramid.
E) The amount of energy represented by producers is equivalent to the amount of energy represented by the secondary consumers.

Question 28

The process of converting nitrogen gas to ammonium is called

A) biogeochemical processing.
B) sublimation.
C) nitrogen fixation.
D) evaporation.
E) nitrification.

Question 29

A population is composed of one or more species of organisms that may interact but do not interbreed.

Question 30

In plants, ammonium is often converted to nitrate before it can be used by the plant. This process is known as

A) nitrogen fixation.
B) photosynthesis.
C) decarboxylation.
D) nitrification.
E) denitrification.

Question 31

If the population age structure of a country resembles a pyramid, with the pre-reproductive age group the largest proportion of the population, and the post-reproductive age group the smallest, this country can most likely be classified as one of the

A) stable populations.
B) least developed countries.
C) most developed countries.
D) steady-state populations.
E) expanding populations.

Question 32

Once populations exceed the carrying capacity of the environment, environmental resistance increases.

Question 33

Which statement describes the expected population growth in the next 50 years?

A) The population growth will be relatively equal throughout the world.
B) The greatest population growth is likely to occur in the more industrialized countries, including the United States and Europe.
C) Most countries worldwide will achieve zero population growth in the next 10 years.
D) The greatest population growth is likely to occur in the least industrialized countries.
E) There will be a net decline of population, with the United States and other industrialized countries contributing most to the population decline.

Question 34

Which one of the following statements is TRUE regarding the nitrogen cycle?

A) Nitrogen fixation results in the production of nitrogen from carbon.
B) Atmospheric nitrogen is unavailable to living organisms because two nitrogen atoms are held tightly together by a triple covalent bond.
C) Plants take up ammonia directly from the atmosphere.
D) Once nitrogen is "fixed," it must then be converted to nitrogen gas before living organisms can use it.
E) In a balanced ecosystem, nitrogen fixation occurs more often than denitrification.

Question 35

A progression of population changes that are tied to a region's industrial development and the economic well-being of its citizens is referred to as

A) replacement rate.
B) succession.
C) MICs.
D) population resistance.
E) demographic transition.

Question 36

The biosphere is so large that, unlike the case of the more simple ecosystems, it is impossible to disturb the balances that exist in this ecosystem.

Question 37

A species moving into a new habitat will be able to adapt only if there is genetic change in the population.

Question 38

The phosphorus cycle is unique from nitrogen and carbon in that it

A) forms the most layers of sediment.
B) is found only in aquatic environments.
C) is restricted to ocean habitats.
D) can be found anywhere.
E) never enters the atmosphere.

Question 39

Slow weathering of sedimentary rock makes "new" ________ available in the exchange pool found in soil.

A) phosphorus
B) nitrogen
C) high-energy carbohydrates
D) PCBs
E) oxygen

Question 40

Which one of the following is represented by the calculation: (number of births - number of deaths)/total population?

A) fertility rate
B) birth rate
C) population growth rate
D) replacement fertility rate
E) zero population growth

Question 41

According to the second law of thermodynamics, when energy is converted from one form to another, some of that energy is transformed into heat energy, which is generally released from the "system."

Question 42

As soon as a population achieves the replacement fertility rate of 2.1, the population will stop growing.

Question 43

Nutrients cycle most rapidly with the reservoir pool of a biogeochemical cycle and least rapidly with the biomass pool.

Question 44

Match each term to its definition.

A) habitat
B) ecosystem
C) geographic range
D) niche
E) community
all populations of all species occupying the same geographical area

Question 45

Match each term to its definition.

A) habitat
B) ecosystem
C) geographic range
D) niche
E) community
the role of an organism in its community

Question 46

With the exception of lipids, plants are capable of producing all the organic molecules they need using water and minerals from the soil and energy stored in the sugar molecules they make through photosynthesis.

Question 47

Match each term to its definition.

A) habitat
B) ecosystem
C) geographic range
D) niche
E) community
a community of organisms and the physical environment in which they live

Question 48

Because a food chain underestimates the degree of complexity in most ecosystems, a food web is a more accurate depiction of the feeding relationships in an ecosystem.

Question 49

Modern farming practices have advanced to the point where they have little impact on the balance of existing ecosystems in the area.

Question 50

The introduction of invasive species may increase the environmental resistance for a native species.

Question 51

Match each term to its definition.

A) habitat
B) ecosystem
C) geographic range
D) niche
E) community
the location of a particular organism; characterized by certain chemical and physical features

Question 52

Match the following.

A) herbivore
B) decomposer, carnivore
C) omnivore
D) producer
a blow fly feeding on a corpse

Question 53

The majority of precipitation reaching land is derived from evaporation of oceanic waters.

Question 54

Major end products from photosynthesis include oxygen gas and simple, high-energy carbohydrates.

Question 55

Match the following.

A) herbivore
B) decomposer, carnivore
C) omnivore
D) producer
a bee drinking nectar from a flower

Question 56

A population that is increasing at a rate of 10% a year will double in 7.2 years.

Question 57

Match each term to its definition.

A) habitat
B) ecosystem
C) geographic range
D) niche
E) community
area in which the species is distributed

Question 58

Mature communities generally exhibit the greatest species diversity.

Question 59

Chemicals that make up living organisms are constantly recycled between organisms and the Earth.

Question 60

A niche is the location within an environment where a species lives.

Question 61

Each chemical element cycles between three different pools of the biogeochemical cycle: the exchange pool, biomass, and reservoir. Match each of the following to the pool in which it would be classified. Answers may be used more than once.

A) exchange pool
B) biomass
C) reservoir
minerals in solid rock

Question 62

Match the following.

A) herbivore
B) decomposer, carnivore
C) omnivore
D) producer
a cow feeding on grass in a field

Question 63

Each chemical element cycles between three different pools of the biogeochemical cycle: the exchange pool, biomass, and reservoir. Match each of the following to the pool in which it would be classified. Answers may be used more than once.

A) exchange pool
B) biomass
C) reservoir
carbon dioxide in the atmosphere

Question 64

Match the following.

A) herbivore
B) decomposer, carnivore
C) omnivore
D) producer
a human eating a dinner of broccoli, baked potatoes, and steak

Question 65

Each chemical element cycles between three different pools of the biogeochemical cycle: the exchange pool, biomass, and reservoir. Match each of the following to the pool in which it would be classified. Answers may be used more than once.

A) exchange pool
B) biomass
C) reservoir
a deer eating grass

Question 66

The size of a population of a given species that can be indefinitely sustained by an ecosystem is its ________.

Question 67

The number of offspring produced by each reproducing member of a species, the ratio of males to females, and the time it takes offspring to become reproductively mature are determinants of the ________ of a population.

Question 68

The point at which the number of births equals the number of deaths is called ________.

Question 69

The study of the relationship between living organisms and their physical environment is called ________.

Question 70

Biogeochemical cycles that involve exchange between living organisms and atmospheric gases are called ________ cycles.

Question 71

The type of location where a species lives is its ________.

Question 72

During photosynthesis, high-energy carbohydrates are produced during the ________.

Question 73

The process by which there is a natural sequence of change in the type of organisms within a particular community is called ________.

Question 74

The ________ is an organism's role in its community.

Question 75

Factors in the environment that limit the ability of a species to meet its biotic potential are known as ________ factors.

Question 76

In a given geographic location, the combination of all living organisms plus the physical environment in which they live is termed a(n) ________.

Question 77

Excess sugar produced by plants is stored in the form of ________ in cells of their seeds, fruits, or roots.

Question 78

Each chemical element cycles between three different pools of the biogeochemical cycle: the exchange pool, biomass, and reservoir. Match each of the following to the pool in which it would be classified. Answers may be used more than once.

A) exchange pool
B) biomass
C) reservoir
carbon-containing compounds in fossil fuels

Question 79

Match the following.

A) herbivore
B) decomposer, carnivore
C) omnivore
D) producer
a plant producing high-energy carbohydrates from carbon dioxide and water, using energy from the sun

Question 80

For an organism reaching its biotic potential, the growth rate is characterized by a(n) ________ curve.