Final Review
LCHS
2013
Which type of rock listed below covers the
majority of the Earth’s land surface?
I. Igneous
II. Metamorphic
III. Sedimentary
A. I only
B. II only
C. III only
D. I and II
E. II and III
C
Igneous rocks are formed when magma (molten rock
deep within the Earth) cools and hardens.
Sometimes the magma cools inside the Earth, and
other times it erupts onto the surface from volcanoes
as lava. Examples of this rock type include basalt
and obsidian.
Metamorphic rocks are formed under the surface of
the Earth from the change that occurs due to intense
heat and pressure. The rocks that result from these
processes often have ribbon-like layers and may
have shiny crystals formed by minerals growing
slowly over time on their surface. Examples of this
rock type include gneiss and marble.
Which of the following statements is NOT true
regarding clumped distribution patterns?
A. It is the most common type of dispersion found in
nature.
B. The distance between neighboring individuals is
maximized.
C. It is found in environments that are characterized by
patch resources.
D. Organisms that usually serve as prey form clumped
distributions in areas where they can hide.
E. It can serve as a mechanism against predation as
well as an efficient mechanism to trap or corner prey.
B: Clumped distribution is the most common type of
dispersion found in nature. In clumped distribution, the
distance between neighboring individuals is minimized.
This type of distribution is found in environments that are
characterized by patchy resources. Clumped distribution is
the most common type of dispersion found in nature because
animals need certain resources to survive, and when these
resources become rare during certain parts of the year,
animals tend to "clump" together around these crucial
resources. Individuals might be clustered together in an area
due to social factors such as herding and family groups.
Organisms that usually serve as prey form clumped
distributions in areas where they can hide and detect
predators easily.
Canada's net population growth was 0.9%
in 2006. What was its approximate
doubling time?
A. 9 years
B. 19 years
C. 42 years
D. 58 years
E. 78 years
E
The population doubling time is the period of time
required for a country to double in the number of people.
When the relative growth rate is constant, the quantity
undergoes exponential growth and has a constant doubling
time or period that can be calculated directly from the
growth rate. This time can be approximated by dividing 70
(more accurately by 72) by the percentage growth rate.
Doubling time = 70/0.9 = 78 years
Thus if the growth rate remains constant, Canada's
population would double from its 2006 population of 33
million to 66 million by the year 2084
Which country listed below ranks largest
in their percent of global agricultural
output?
A. United States
B. China
C. India
D. Russia
E. European Union
B
Agriculture is a vital industry in China, employing over
300 million farmers. China ranks first in worldwide farm
output, primarily producing rice, wheat, potatoes, sorghum,
peanuts, tea, millet, barley, cotton, oilseed, pork, and fish.
Beginning in about 7700 BCE with millet agriculture,
China's development of farming over the course of its
history has played a key role in supporting the growth of
what is now the largest population in the world.
Although China's agricultural output is the largest in the
world, only about 15% of its total land area can be
cultivated. China's arable land, which represents 10% of the
total arable land in the world, supports over 20% of the
world's population. Only about 1.2% of all arable land in
China permanently supports crops.
Which of the following is most likely to occur
in a forested region that has been recently clearcut?
(A) The concentration of nitrates in streams
running through the region will increase.
(B) The average depth of topsoil will increase.
(C) The water temperature in streams running
through the region will decrease.
(D) Volume of runoff after rains will decrease.
(E) The frequency of landslides will decrease.
Which specific air pollutant do CAFE
standards NOT address?
A. Carbon monoxide
B. Carbon dioxide
C. NOx
D. SOx
E. Formaldehyde
B–
First enacted by Congress in 1975, the purpose of Corporate Average
Fuel Economy (CAFE) is to reduce energy consumption by increasing the
fuel economy of cars and light trucks.
The National Highway Traffic Safety Administration (NHTSA) sets fuel
economy standards for cars and light trucks sold in the United States and
administers the CAFE program, while the Environmental Protection Agency
(EPA) provides the fuel economy data and manages emissions standards
although state and local governments may enact stricter regulations.
Currently there are three sets, or "tiers," of emission standards for light-duty
vehicles in the United States. These standards specifically restrict emissions
of carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter
(PM), formaldehyde (HCHO), non-methane organic gases (NMOG), and
non-methane hydrocarbons (NMHC) and the amount of sulfur allowed in
gasoline and diesel fuel, since sulfur can interfere with the operation of
advanced exhaust treatment systems such as selective catalytic converters
and particulate filters. Federal emission regulations addressed through CAFE
standards do not cover the primary component of vehicle exhaust, carbon
dioxide (CO2) since CO2 emissions are proportional to the amount of fuel
used.
A senior-citizen housing development agency
in a large, metropolitan area decided to
incorporate the latest hurricane-resistant
design features into a new housing project
even though the area was not prone to
frequent hurricanes. This is an example of
A. cost overrun
B. mitigation
C. remediation
D. preservation
E. restoration
B - Mitigation is the elimination or reduction
of the frequency, magnitude, or severity of
exposure to risks, or minimization of the
potential impact of a threat or warning.
Preservation includes activities designed to
perpetuate existing facilities in their
original condition. Restoration involves
activities designed to repair existing
facilities. Remediation involves activities in
correcting a fault or deficiency in an
existing facility.
The climatogram would be typical for a
A. coniferous forest
B. tropical rainforest
C. grassland
D. desert
E. taiga
A - Between the tundra to the north and the deciduous forest
to the south lies the large area of coniferous forest. One type of
coniferous forest, the northern boreal forest, is found between
50° to 60°N latitudes. Another type, the temperate coniferous
forests, grows in lower latitudes of North America, Europe, and
Asia, in the high elevations of mountains.
Coniferous forests consist mostly of conifers, trees that grow
needles instead of leaves and cones instead of flowers. Conifers
tend to be evergreen, that is, they bear needles all year long.
These adaptations help conifers survive in areas that are very
cold or dry. Some of the more common conifers are spruces,
pines, and firs.
Precipitation in coniferous forests varies from 12" to 35" (300
to 900 mm) annually, with some temperate coniferous forests
receiving up to 80" (2,000 mm). The amount of precipitation
depends on the forest location. In the northern boreal forests, the
winters are long, cold, and dry, whereas the short summers are
moderately warm and moist. In the lower latitudes, precipitation
is more evenly distributed throughout the year.
As the population of current developing countries undergo a
demographic transition, which of the following are most
likely to occur?
I. Urban populations will increase as people migrate to cities
to find employment.
II. Rural populations will increase as larger populations will
require more food.
III. Food shortages and famine will decrease as an increase
in urban populations increases the efficiency of food
distribution and supply.
A. I only
B. II only
C. III only
D. I and III
E. I, II, and III
B - Pollutants can be classified as primary or secondary. Primary pollutants are directly emitted from a process, such as ash from a
volcanic eruption, carbon monoxide gas from a motor vehicle exhaust, or sulfur dioxide from factories. Secondary pollutants are
not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary
pollutant is ground level (tropospheric) ozone—one of the many secondary pollutants that make up photochemical smog. Some
pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.
Primary pollutants
• Sulfur dioxide (SO2) is produced from burning coal mainly in thermal power plants. It causes smog and acid rain.
• Nitrogen oxides (NOx) cause smog and acid rain. It is produced from burning fuels including petrol, diesel, and coal.
• Carbon monoxide (CO) is a product of incomplete combustion of fuel such as natural gas, coal, or wood.
• Chlorofluorocarbons (CFCs), released mainly from refrigeration, combine with a few other gases. This combination leads to a
reduction of the ozone layer, which protects the Earth from the harmful ultraviolet rays of the sun.
• Carbon dioxide (CO2) is a greenhouse gas emitted from combustion.
• Particulate matter (PMx) includes smoke, dust, and vapor that can remain suspended for extended periods and can be
introduced in the environment as primary as well as secondary pollutants.
• Toxic metals, such as lead, cadmium, and copper, can enter to the environment through petrol, hair dye products, paints,
batteries, etc.
• Volatile organic compounds (VOC) include hydrocarbon fuel vapors and solvents.
• Ammonia (NH3) is emitted from agricultural processes.
• Odors emanate from garbage, sewage, and industrial processes.
• Radioactive pollutants are produced by nuclear explosions and war explosives, as well as by natural processes such as radon.
Secondary pollutants
• Particulate matter is formed from gaseous primary pollutants and compounds in photochemical smog, such as nitrogen dioxide.
• Ground level ozone (O3) is formed from NOx and VOCs.
• Peroxyacetyl nitrate (PAN) is similarly formed from NO2 and VOCs.
A - The human population has lived a rural lifestyle through most of history. The world’s
population, however, is quickly becoming urbanized as people migrate to the cities. In 1950, less
than 30% of the world’s population lived in cities. The urban population grew to 47% in the year
2000, and it is expected to grow to over 60% by the year 2030.
Developed nations have a higher percentage of urban residents than less-developed countries.
However, urbanization is occurring rapidly in many less-developed countries, and it is expected that
most urban growth will occur in less-developed countries during the next decades.
The rapid growth of urban areas is the result of two factors: natural increase in population and
migration to urban areas.
Migration is often explained in terms of either "push factors"—conditions in the place of origin
that are perceived by migrants as detrimental to their well-being or economic security—and "pull
factors"—the circumstances in new places that attract individuals to move there. Examples of push
factors include high unemployment and political persecution, while examples of pull factors include
increased job opportunities or greater educational opportunities.
Governmental policies also foster internal migration in many developing countries. For
example, in order to pay foreign debt and to be more competitive in international markets, national
governments have encouraged the export of national resources and agricultural products. Such
products become natural resource capital that can be traded to bolster the national economies of
developing countries. In order to produce agricultural products quickly, efficiently, and at lower
prices, national governments often look to decrease the number of small producers and turn
agricultural production and resource extraction over to larger enterprises, with larger production
facilities and a lower per-unit cost of production. These policies turn land into a commodity that can
be bought and sold, and it is viewed only in terms of its productive capabilities.
In 1995 a certain model of car had a rating of
20.0 miles per gallon. In 2010, the same
model had a rating of 30.0 miles per gallon.
What was the percentage change in car fuel
mileage?
A. 25%
B. 33%
C. 50%
D. 66%
E. 133%
C – The general equation for
percentage change is
(Nfinal – N initial) × 100 = % change
N initial
(30 – 20) × 100 = 50.0%
20
Which of the following air pollutants
is classified as a "secondary" air
pollutant?
A. SOx
B. Tropospheric ozone
C. NOx
D. Stratospheric ozone
E. VOC
Zero population growth is associated with
(A) phase I only
(B) phase II only
(C) phase III only
(D) phase IV only
(E) phases I and IV
The rate of population
growth starts to slow
down at which point?
(A) The end of phase I
(B) The middle of phase II
(C) The beginning of phase III
(D) The end of phase III
(E) The middle of phase IV
Which of the following
is most likely the primary
cause of high death rates
in phase I?
(A) Loss of breeding-age males due to warfare
(B) Loss of breeding-age females due to disease
(C) Large percentage of elderly individuals in
the population
(D) Infant and childhood mortality
(E) General starvation due to famine
Which of the following graphs shows
human population growth over the last
1,000 years?
A.
B.
C.
D.
E.
A.
The human population has dramatically increased in recent times. Two thousand years
ago, the Earth had approximately 300 million humans, about the population of the United
States today. Two hundred years ago, the world population was about three times that
number. Today, it is now more than 6 billion and growing rapidly. If current trends
continue, there will be an additional 1 billion added to the world population every 13 or
14 years.
This explosive growth came about because death rates fell faster than birth rates. The
availability of antibiotics, immunizations, clean water, and increased food production
yielded tremendous improvements in infant and child mortality. A rise in average life
expectancy has also contributed to the surge in human numbers.
Fertility is a key factor in determining population growth over the long term. In order
to maintain a stable population size, a total fertility rate (TFR) of 2.1 is needed and
represents the total number of children an average woman will bear over her lifetime.
The worldwide average TFR is 2.9, with the United States having a TFR of 2.1. Even
with a TFR of 2.1, the United States and similar countries will still see its population
increase, as children born in previous years reach adulthood and begin having offspring.
Only after TFR values have remained low for a generation or longer will population size
level off or decrease.
Approximately what percentage of the
world’s fresh water is readily available for
human use?
A. 0.00003
B. 0.003
C. 0.3
D. 3
E. 30
B. Approximately 97% of Earth’s water is
found in the oceans, with only 3% of all
water on Earth being fresh water. Of this
fresh water, more than 68% is trapped and
frozen in icecaps and glaciers, and about
1% is readily accessible in surface waters.
Only 0.003% of Earth’s water is readily
available and usable for human daily needs.
To put this into perspective, if all the water
on Earth could fit in a 26-gallon barrel, only
1 teaspoon of it would be fresh water
readily available for human use.
The problem of bioaccumulation of
pesticides was first brought to the public’s
attention by
A. John Muir
B. Aldo Leopold
C. Henry David Thoreau
D. Rachel Carson
E. Garrett Hardin
D - Silent Spring written by Rachel Carson is widely
credited with helping launch the environmental movement.
When the book Silent Spring was published, Rachel Carson
was already a well-known writer on natural history, but she
had not previously been a social critic. The book was widely
read and inspired widespread public concerns with
pesticides and pollution of the environment. Silent Spring
facilitated the ban of the pesticide DDT in 1972 in the
United States. The book documented detrimental effects of
pesticides on the environment, particularly on birds. Carson
accused the chemical industry of spreading disinformation,
and public officials of accepting industry claims uncritically.
Noise pollution can cause all of the
following EXCEPT
A. stress
B. increased respiration rate
C. increased heart rate
D. tinnitus
E. aggression
B - Noise pollution is excessive, displeasing human, animal, or machine-created environmental noise
that disrupts the activity or balance of human or animal life. High noise levels can contribute to
cardiovascular effects in humans, a rise in blood pressure, an increase in stress and vasoconstriction, and
an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by
altering predator or prey detection and avoidance, interfere with reproduction and navigation, and
contribute to permanent hearing loss.
Noise pollution affects both health and behavior. Unwanted sound (noise) can also damage
physiological and psychological health. Noise pollution can cause annoyance and aggression,
hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects.
Furthermore, stress and hypertension are the leading causes of health problems.
Chronic exposure to noise may cause noise-induced hearing loss. Older males exposed to significant
occupational noise demonstrate significantly reduced hearing sensitivity than their non-exposed peers,
though differences in hearing sensitivity decrease with time, and the two groups are indistinguishable by
age 79.
High noise levels can contribute to cardiovascular effects, and exposure to moderately high levels
during a single eight-hour period causes a statistical rise in blood pressure of five to ten points and an
increase in stress and vasoconstriction leading to the increased blood pressure noted above as well as to
increased incidence of coronary artery disease.
Noise can have a detrimental effect on animals, increasing the risk of death by changing the delicate
balance in predator or prey detection and avoidance and interfering with the use of the sounds in
communication especially in relation to reproduction and in navigation. Overexposure can lead to
temporary or permanent loss of hearing.
An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which
in the case of endangered species may be part of the path to extinction. Noise pollution has caused the
death of certain species of whales that beached themselves after being exposed to the loud sound of
military sonar.
The Surface Mining Control and Reclamation Act
of 1977
I. Requires restoration of mined land to its
former condition.
II. Regulates the mining methods to be used.
III. Grants free access to individuals to
prospect for minerals on public land.
A. I only
B. II only
C. III only
D. II and III
E. I, II, and III
A - The Surface Mining Control and Reclamation Act of 1977 (SMCRA) is the
primary federal law that regulates the environmental effects of coal mining in the
United States.
The regulation of active mines under SMCRA has several major components:
Sets environmental standards that mines must follow while operating and achieve
when reclaiming mined land;
Requires mining companies to obtain permits before conducting surface mining
on all land in the United States. Permit applications must describe what the premining environmental conditions and land use are, what the proposed mining and
reclamation will be, how the mine will meet the SMCRA performance standards, and
how the land will be used after reclamation is complete;
Requires that mining companies post a bond sufficient to cover the cost of
reclaiming the site;
Gives government regulators the authority to inspect mining operations and to
punish companies that violate SMCRA or an equivalent state statute; and
Gives government regulators the authority to prohibit surface mining on certain
lands, such as in National Parks and wilderness areas and allows citizens to
challenge proposed surface mining operations on the ground that it will cause too
much environmental harm
Exposure to small doses of a toxic
chemical over a long period of time is
known as
A. acute exposure
B. chronic exposure
C. hazardous exposure
D. sustained exposure
E. toxicity
B - Toxicity is the ability of a substance to produce an unwanted effect when the
chemical has reached a sufficient concentration. The more toxic a material is, the
smaller the amount of it necessary to be absorbed before harmful effects are caused
(i.e., the lower the toxicity, the greater the quantity of it necessary to be absorbed}.
Hazardous is the probability that this concentration will occur while toxicity is an
inherent property of the material. A material may be very toxic, but not hazardous, if
it is handled properly and is not absorbed into the body. On the other hand, a
material may have a very low toxicity but be very hazardous. Example: An open
container of an acid is much more hazardous than a closed container of the same
material. The toxicity of the material is the same, but the closed container is less
hazardous as the probability of it causing harm is decreased.
Exposure can be classified as chronic or acute. In chronic exposures, the dose is
delivered at some frequency over a period of time. In acute exposures, the dose is
delivered in a single event, and absorption is rapid. Usually, a chronic exposure
occurs at low concentration, and acute exposure at high concentration. Some
materials may only cause harm if given acutely, not having any effect in the long
term, whereas other materials may not exhibit an effect in the short term but may
cause problems after prolonged exposure.
Approximately what percentage of all
species of life that have ever lived on
Earth are now extinct?
A. 0.1%
B. 5%
C.25%
D. 50%
E. 99%
E
Most species of life that have existed on Earth have vanished as a result of normal or
background extinction, which fluctuates from 1 million years with mammals through 11 million
years with some marine invertebrates. Besides normal, background extinction, animal life has
experienced five mass extinctions, resulting in 50 to 95% of life disappearing within a limited time
period. The first mass extinction occurred 440 million years ago, at the end of Ordovician, as a
result of temperature fall and the resulting decrease in ocean levels. The second wave took place
during the late Devonian, again due to temperature fall and ocean level lowering. During the third
wave of extinction, at the end of Permian, approximately 250 million years ago, 95% of marine
species and nearly 70% of terrestrial species disappeared due to active reconstruction of the Earth's
crust and change of climate during the formation of the supercontinent Pangaea. The fourth
extinction happened in the late Triassic, and the fifth and most recent one—resulting in the
disappearance of dinosaurs—appeared about 65 million years ago. It was most likely due to the
Earth colliding with an asteroid, resulting in cataclysmic tsunamis, acid rains, and the sea being
covered by enormous amount of soil and organic matter, with only 12% of the then-existing species
surviving on land.
The predicted sixth extinction will be anthropogenic in nature, or due to the activities of
humans.
A recent analysis, published in the journal Nature, shows that it takes 10 million years before
biological diversity even begins to approach what existed before a die-off. More than 10,000
scientists in the World Conservation Union have compiled data showing that currently 51% of
known reptiles and insects and 73% of known flowering plants are in danger, as are many
mammals, birds, and amphibians. It is likely that some species will become extinct before they are
even discovered, before any medicinal use or other important features can be assessed. Given the
current average extinction rate of 40 species a day, it would take only 16 thousand years for the
extinction of 96% of all Earth’s current life forms.
Which of the following plant nutrients
would most likely be a limiting
factor?
A. Nitrogen
B. Sulfur
C. Phosphorus
D. Calcium
E. Compost
C – All plants have specific requirements for 17 basic
nutrients. Of those 17 nutrients, 14 (including the primary
nutrients of nitrogen, phosphorus, and potassium) are
derived from the soil. Phosphorus is an essential nutrient
and available for plants and animals in the form of the
phosphate ion PO43−. It can be found in DNA molecules,
molecules that store energy (ATP and ADP), and the fats of
cell membranes. Phosphorus is also essential for certain
parts of the human and animal body, such as the bones and
teeth.
Phosphorus can be found on the Earth in water and soil. It
is mainly cycling through water, soil, and sediments.
Phosphorus moves slowly from deposits on land and in
sediments, to living organisms, and much more slowly back
into the soil and water sediment. The phosphorus cycle is
the slowest one of the matter cycles.
Humans in developed countries would
typically have what type of survivorship
curve?
A. I
B. II
C. III
D.I and II
E. II and III
Examples of populations with Type I
survivorship include humans in developed
countries and animals in zoos. A lot of effort
is invested in each individual, resulting in
high survivorship throughout the life cycle
and a state where most individuals die of old
age. In general, this is more typical of Kselected species, which tend to grow in stable
environments where intense competition
between individuals is experienced. The
heavy parental investment improves
competitive ability and makes it more likely
that individuals will survive to reproduction.
The city council of a small town was considering proposals from
various special interest groups on what to do with a large tract of
public land within its jurisdiction that contained a large number of
trees. Listed below are several proposals from various groups. Which
proposal listed below is most in line with the precautionary principle?
A. Do a study to determine the estimated sustainable yield of
harvesting the trees. Then harvest trees below that level
B. Do a study to determine the estimated sustainable yield of
harvesting the trees. Then harvest trees at that level
C. Remove all trees and sell them for lumber, which would provide
income to the city. Then build a parking lot on the site which
would add a continuing source of revenue for the city.
D. Remove all the trees and sell them for lumber. Then convert the
land to a sustainable tree farm to make efficient and profitable in
the future.
D. Do nothing. Keep the land as it is.
A - The precautionary principle states that if an action or policy has a suspected risk of
causing harm to the public or to the environment, in the absence of scientific consensus
that the action or policy is harmful, the burden of proof that it is not harmful falls on
those taking the action. This principle allows policy makers to make discretionary
decisions in situations where there is the possibility of harm from taking a particular
course or making a certain decision when extensive scientific knowledge on the matter is
lacking. The principle implies that there is a social responsibility to protect the public
from exposure to harm, when scientific investigation has found a plausible risk. These
protections can be relaxed or modified only if further scientific findings emerge that
provide sound evidence that no harm will result. The European Union has made the
application of the precautionary principle a statutory requirement.
Areas typically concerned by the precautionary principle include
• Global warming,
• Extinction of species,
• Introduction of new and potentially harmful products into the environment,
threatening biodiversity (e.g., genetically modified organisms),
• Threats to public health, due to new diseases and techniques (e.g., AIDS transmitted
through blood transfusion),
• Long-term effects of new technologies (e.g., health concerns regarding radiation
from cell phones),
• Persistent or acute pollution (e.g., asbestos, endocrine disruptors),
• Food safety,
• Biosafety issues (e.g., recombinant DNA or "gene splicing").
An AP class was doing a field study of a lake. The class determined the
amount of dissolved oxygen in the lake water at a depth of 2 feet through a
titration technique and determined the amount to be 8 mg O2 per liter of lake
water.
Then the class filled and sealed two clear glass bottles with lake water from
the same location and depth, labeling one bottle "Light" and the other bottle
"Dark." The "Dark" bottle was wrapped completely with several layers of
foil. Both bottles were then lowered 3 feet into the lake at the same location
where the initial sample was taken.
After one hour, the bottles were retrieved, and, again through titration, the
amount of oxygen in the water in the "Light" bottle was determined to be 10
mg O2 per liter while the amount of oxygen in the water in the "Dark" bottle
was determined to be 5 mg O2 per liter .
The net primary productivity of the lake water sample was
A. 2 mg O2 per liter per hour
B. 3 mg O2 per liter per hour
C. 4 mg O2 per liter per hour
D. 5 mg O2 per liter per hour
E. 8 mg O2 per liter per hour
A - Net primary productivity is just the energy
going to new plant growth.
The water contains both microscopic plants
and animals of the aquatic ecosystem. In the light
bottle there is photosynthesis, or Gross Primary
Production (GPP), and there is Respiration (R).
The difference between these two processes is
Net Primary Production: NPP = (GPP – R)
NPP
= (GPP – R)/Time
= (10 mg O2/L - 8 mg O2/L )/1 hr
= 2 mg O2/L /hr
An AP class was doing a field study of a lake. The class determined the
amount of dissolved oxygen in the lake water at a depth of 2 feet through a
titration technique and determined the amount to be 8 mg O2 per liter of lake
water.
Then the class filled and sealed two clear glass bottles with lake water from
the same location and depth, labeling one bottle "Light" and the other bottle
"Dark." The "Dark" bottle was wrapped completely with several layers of
foil. Both bottles were then lowered 3 feet into the lake at the same location
where the initial sample was taken.
After one hour, the bottles were retrieved, and, again through titration, the
amount of oxygen in the water in the "Light" bottle was determined to be 10
mg O2 per liter while the amount of oxygen in the water in the "Dark" bottle
was determined to be 5 mg O2 per liter .
What was the gross primary production (GPP)?
A. 2 mg O2 per liter per hour
B. 3 mg O2 per liter per hour
C. 4 mg O2 per liter per hour
D. 5 mg O2 per liter per hour
E. 10 mg O2 per liter per hour
E - In the dark bottle, there is no photosynthesis, only respiration. Primary productivity is
a term used to describe the rate at which plants and other photosynthetic organisms
produce organic compounds in an ecosystem. There are two aspects of primary
productivity:
(1) net productivity, the organic materials that remain after photosynthetic organisms in
the ecosystem have used some of these compounds for their cellular energy needs
(cellular respiration), and
(2) gross primary productivity, the entire photosynthetic production of organic
compounds in an ecosystem. Since oxygen is one of the most easily measured products
of both photosynthesis and respiration, a good way to gauge primary productivity in an
aquatic ecosystem is to measure dissolved oxygen; however, gross productivity cannot be
measured directly because respiration, which uses up oxygen and organic compounds, is
always occurring simultaneously with photosynthesis.
We can measure net productivity directly by measuring oxygen production in the light,
when photosynthesis is occurring.
We can also measure respiration without photosynthesis by measuring O2 consumption
in the dark, when photosynthesis does not occur.
Since Net Primary Productivity = Gross Primary Productivity – Respiration, we can
calculate Gross Primary Productivity.
GPP = (NPP + R)/ time = (2 mg O2/L + 8 mg O2/L)/1 hr = 10 mg O2/L /hr
Which of the following traits is NOT
characteristic of an r-selected species?
A. low fertility
B. small body size
C. early maturity onset
D. short gestation time
E. ability to disperse offspring widely
A - Examples of r-strategists include small rodents, insects,
bacteria, and annual plants. r/K selection theory relates to
the selection of combinations of traits in an organism that
trade off between quantity and quality of offspring. The
focus upon either increased quantity of offspring at the
expense of individual parental investment or reduced
quantity of offspring with a corresponding increased
parental investment varies widely, seemingly to promote
success in particular environments.
Because of their higher reproductive rates and ecological
opportunism, primary colonizers typically are r-strategists
and are followed by a succession of increasingly
competitive flora and fauna. Eventually a new equilibrium is
approached (climax community) with r-strategists gradually
being replaced by K-strategists, which are more competitive
and better adapted to the emerging characteristics of the
environment
Which of the following
would most effectively
slow the loss of arable
land?
(A)Increasing the efficiency of desalination
processes
(B)Reducing urban development
(C)Increasing the efficiency of erosion control
(D)Using more extensive irrigation systems
(E) Discovering cheaper energy sources
Which of the following statements is NOT consistent
with the second law of thermodynamics?
I. When energy is converted from one form to
another, the resulting form is always lowerquality energy and heat is generally given off.
II. When energy is converted from one form to
another, entropy increases; in other words, the
energy is more dispersed.
III. Energy can neither be created nor destroyed.
A. I only
B. II only
C. III only
D. I and III
E. I, II and III
C - Thermodynamics is the study of energy. Energy is the ability to bring about change or to
do work and exists in many forms (e.g., heat, light, chemical energy, and electrical energy).
The First Law of Thermodynamics states that the total amount of energy and matter in
the universe remains constant (it cannot be created nor destroyed), but that it can change from
one form to another (e.g., electrical energy → heat energy).
The Second Law of Thermodynamics is concerned with disorder or entropy. The
universe is spontaneously moving in the direction of increased entropy or disorder. The
driving force of all energy change therefore is the unstoppable tendency of energy to flow
from high concentrations of energy (high quality) to lower concentrations of energy (low
quality).
Example: When a diesel engine turns a generator, diesel fuel is burned, which converts
the concentrated chemical energy in the diesel fuel into heat energy through combustion and
then into the engine's mechanical energy, which is then converted into electrical energy by the
generator. However, not all of the energy released from the diesel fuel is converted to the final
form—electricity. Some of the energy is lost through friction and heat; for example, the
moving parts of the generator produce heat and the generator wires being heated up by
internal friction as electrons flow through them, and the generator requires energy to run
cooling fans to keep it cool. Finally, as the electrical energy flows through the electrical
transmission lines, the wires are heated by the flowing electrons, and even more energy is lost
as the electrical wires heat up the air surrounding them. All of this "other" energy is still there,
but can no longer be used for the intended purpose of generating electricity.
The Second Law of Thermodynamics also explains the progressive loss of energy as
energy moves from a concentrated source (primary producer) to a higher order consumer
through a food chain and explains why more people could be fed by eating plants and plant
products than by eating meat.
The distribution of biomes around the world are in
large part determined by long-term seasonal
weather patterns which themselves are primarily
determined by
A. the distance from the Earth to the sun during a
particular time of the year
B. the amount of solar radiation that is released by
the sun during certain periods of the year
C. the angle at which solar radiation reaches the
Earth
D. trade winds
E. ocean currents
C - World biomes are primarily determined by
climate. Climate is the long-term weather pattern of an
area of the Earth, which includes the region's general
pattern of weather conditions, seasons and weather
extremes (e.g., hurricanes, droughts, or rainy periods).
Two of the most important factors determining an
area's climate are air temperature and precipitation.
The sun's rays hit the equator at a direct angle
between 23° N and 23° S latitude. Radiation that
reaches the atmosphere within these areas is at its
most intense resulting in areas of the Earth that are the
warmest. In all other cases, the rays arrive at an angle
to the surface and are less intense. The closer an area
is to the South or North Pole, the smaller the angle and
therefore the less intense the radiation.
The practice of harvesting trees in a way
that moves a forest stand toward an
uneven-aged or all-aged condition or
"structure" is known as
A. clear cutting
B. shelterwood cutting
C. old growth cutting
D. seed tree harvesting
E. selective cutting
E - Silviculture is the practice of controlling the
establishment, growth, composition, health, and quality of
forests to meet diverse needs and values. Selection cutting is
the practice of harvesting trees in a way that moves a forest
stand toward an all-aged condition also known as "unevenaged" structure.
"Selection" cutting is often confused with "selective"
cutting, a term synonymous with the practice of highgrading (the removal of the best trees in a forest) often with
a disregard for the future of the residual stand.
The most common isotope used as a fuel
in nuclear reactors that produce electrical
energy is
A. U235
B. U236
C. U238
D. Pu239
E. He4
Uranium-235 (U235) is an isotope of uranium making up
about 0.72% of naturally occurring uranium. Before it can
be used, however, its concentration must be increased or
"enriched." Unlike the more predominant isotope uranium238, U235 can sustain a chain reaction. It is the only fissile
isotope that is found in significant quantity in nature, and it
has a half-life of 700 million years.
During a chain reaction, a neutron is absorbed by a
uranium-235 nucleus, turning it briefly into an excited
uranium-236 nucleus, with the excitation energy provided
by the kinetic energy of the neutron plus the forces that bind
the neutron. The uranium-236, in turn, splits into fastmoving lighter elements (fission products) and releases three
free neutrons and gamma radiation. The heat that is
produced in this reaction is used by most nuclear power
plants today to produce steam, which spins turbines
connected to electrical generators.
The pollutant found in the largest
amount in agricultural runoff is
A. soil
B. animal wastes
C. fertilizer
D. pesticides
E. crop residue
A - Agriculture is a highly intensified industry in many parts
of the world, producing a range of wastewaters requiring a
variety of treatment technologies and management practices.
Soil washed off fields is the largest source of agricultural
pollution. Excess sediment causes high levels of turbidity in
water bodies, which can inhibit growth of aquatic plants, clog
fish gills and smother animal larvae.
Farmers may utilize erosion controls to reduce runoff flows
and retain soil on their fields. Common techniques include using
contour plowing, mulching crops, rotating crops, planting
perennial crops, and installing riparian buffers.
Nitrogen and phosphorus are key pollutants found in runoff,
and they are applied to farmland as commercial fertilizer, animal
manure, and municipal or industrial wastewater or sludge. These
chemicals may also enter runoff from crop residues, irrigation
water, wildlife, and atmospheric deposition
A country has a birth rate of 15.5 live
births per 1,000 population and a death
rate of 7.5 per 1,000 population. The
population growth rate is
A. - 0.80
B. - 0.08
C. 0.00
D. 0.08
E. 0.80
E
Growth Rate
= (Birth Rate – Death Rate)/10
= (15.5 – 7.5)/10 = 0.8
Population growth is the change in a population over time
and can be quantified as the change in the number of
individuals in a population per unit of time. Globally, the
growth rate of the human population has been declining
since peaking in 1962 at 2.20% per annum.
In 2009, the estimated annual growth rate was 1.1%. The
world annual birth rate is 1.915%, the mortality rate is
0.812%, and the growth rate is 1.092%. The last one
hundred years have seen a rapid increase in population due
to medical advances and a massive increase in agricultural
productivity made possible by the Green Revolution.
Which biome listed below would contain
soil that is acidic and contains few
nutrients?
A. Desert
B. Grassland
C. Coniferous Forest
D. Deciduous Forest
E. Tropical Rainforest
E - Despite the rapid growth of
vegetation in a tropical rainforest, soil quality
is often quite poor. Rapid bacterial decay
prevents the accumulation of humus. Most
trees have roots near the surface because
there are insufficient nutrients below the
surface as most of the trees' minerals come
from the top layer of decomposing leaves and
animals. If rainforest trees are cleared, rain
can accumulate on the exposed soil surfaces,
creating run-off and beginning the process of
soil erosion.
Most of the world’s garbage belongs to
what category?
A. paper
B. plastic
C. organic
D. metal
E. glass
C - This year, the world will generate 2.6
trillion pounds of garbage. Almost half of
it is classified as "organic," which consists
of food, food animals eat, horticultural
waste, green and garden waste, human
and animal waste, bio-solids, and sludge.
Formation of photochemical smog does
NOT depend upon the presence of
A. sunlight
B. volatile organic compounds (VOCs)
C. NOx
D. peroxyacyl nitrates (PANs)
E. water vapor
D - PANs are produced in the formation
of photochemical smog, they are not
required for its formation.
Which of the following examples would NOT be an
example of environmental remediation?
A. Hauling contaminated soil to a regulated landfill
B. Injecting surfactants into the subsurface to enhance
desorption and recovery of pollutants
C. Pumping out groundwater and allowing the extracted
groundwater to be purified by slowly proceeding
through a series of vessels that contain materials
designed to adsorb the contaminants
D. Injecting oxygen gas into a lake to promote growth
of aerobic bacteria that will accelerate the breakdown
of organic contaminants that have polluted the lake
E. Laying down sandbags and other barriers around a
pond to keep possible runoff from a construction
project from entering it
E - Environmental remediation involves
the removal of pollution or contaminants for
the general protection of human health and
the environment. It consists of actions to
minimize the effects of environmental
damage that have already taken place (i.e.,
after the fact). Choice E is an example of
environmental mitigation, which is the
implementation of measures designed to
reduce the undesirable effects of a proposed
or future action that may affect the
environment (i.e., before the damage occurs).
If an incandescent light bulb used for
lighting has an efficiency rating of 5
percent, then for every 1.00 joule of
electrical energy consumed by the bulb,
which of the following is produced?
(A) 1.05 joules of light energy
(B) 1.05 joules of heat energy
(C) 0.95 joule of light energy
(D) 0.05 joule of light energy
(E) 0.05 joule of heat energy
Stratospheric ozone depletion can
cause all of the following EXCEPT
A. increase in skin cancer
B. increased incidents of cataracts
C. warming of the stratosphere
D. reduction in crop yields
E. increased rates of genetic mutations
C - The lower stratosphere appears to be cooling by about 0.5°C per
decade. This cooling trend is interrupted by large volcanic eruptions, which
lead to a temporary warming of the stratosphere and last for one to two
years. Two reasons for stratospheric cooling are (1) depletion of stratospheric
ozone and (2) increase in atmospheric carbon dioxide.
Less ozone leads to less absorption of ultraviolet radiation from the Sun.
As a result, solar radiation is not converted into heat radiation in the
stratosphere. So cooling due to ozone depletion is reduced as a consequence
of reduced absorption of ultraviolet radiation. Ozone also acts as a
greenhouse gas in the lower stratosphere. Less ozone means less absorption
of infrared heat radiation and therefore less heat trapping.
Greenhouse gases (e.g., CO2, O3, and CFC) absorb infrared radiation
from the surface of the Earth and trap the heat in the troposphere. If this
absorption is strong, the greenhouse gas blocks most of the outgoing infrared
radiation close to the Earth's surface. This means that only a small amount of
outgoing infrared radiation reaches carbon dioxide in the upper troposphere
and the lower stratosphere.
Carbon dioxide also emits heat radiation, which is lost from the
stratosphere into space. In the stratosphere, this emission of heat becomes
larger than the energy received from below by absorption. As a result, there
is a net energy loss from the stratosphere, and cooling results.
The first step in the nitrogen cycle is when
A. nitrogen gas is absorbed by the plants
B. nitrogen gas is converted to ammonia
C. nitrites are converted to nitrates
D. water reacts with nitrates
E. ammonia breaks down to form nitrates
and nitrites
B. Nitrogen fixation is a process by which nitrogen (N2) in the
atmosphere is converted into ammonia (NH3). Atmospheric
nitrogen or elemental nitrogen (N2) is relatively inert: it does not
easily react with other chemicals to form new compounds. Fixation
processes free up the nitrogen atoms to be used in other ways.
There are two main ways nitrogen is "fixed":
About 90% of nitrogen fixation is done by bacteria.
Cyanobacteria convert nitrogen into ammonia and ammonium:
N2 + 3 H2 → 2 NH3 Ammonia can be used by plants directly.
The energy from lightning causes nitrogen (N2) and water
(H2O) to combine to form ammonia (NH3) and nitrates (NO3−).
Precipitation carries the ammonia and nitrates to the ground, where
they can be assimilated by plants.
Nitrogen fixation is essential for all forms of life because
nitrogen is required to biosynthesize basic building blocks of
plants, animals and other life forms (e.g., nucleotides for DNA and
RNA and amino acids for proteins). Therefore, nitrogen fixation is
essential for agriculture and the manufacture of fertilizer.
Which of the following is NOT a common
method employed in the cleanup of oil
spills?
A. skimmer boats
B. bacteria
C.oil dispersants
D. large floating booms
E. incineration
E. Oil is a flammable material. However, within a few hours at sea, it loses most of its volatile
(flammable) components and picks up a high proportion of water. Consequently, burning the oil itself
without first removing the water can be very difficult. Burning oily debris directly in the open is not a
recommended method of disposal, except in very remote areas, due to the resultant smoke levels. When
oil is burned by this method, it also tends to spread and to penetrate into the ground. Additionally, a tarlike residue may remain since it is rarely possible to achieve complete combustion.
However, a number of mechanisms are available for controlling oil spills and minimizing their
impacts on human health and the environment. The key to effectively combating spills is careful selection
and proper use of the equipment and materials best suited to the type of oil and the conditions at the spill
site. Most spill response equipment and materials are greatly affected by such factors as conditions at sea,
water currents, and wind. Damage to spill-contaminated shorelines and dangers to other threatened areas
can be reduced by timely and proper use of containment and recovery equipment.
Mechanical containment or recovery is the primary line of defense against oil spills in the United
States. Containment and recovery equipment includes a variety of booms, barriers, and skimmers, as well
as natural and synthetic absorbing (sorbent) materials. Mechanical containment is used to capture and
store the spilled oil until it can be disposed of properly.
Chemical and biological methods can be used in conjunction with mechanical means for containing
and cleaning up oil spills. Dispersing agents and gelling agents are most useful in helping to keep oil
from reaching shorelines and other sensitive habitats. Biological agents have the potential to assist
recovery in sensitive areas such as shorelines, marshes, and wetlands. There are three kinds of oilconsuming bacteria: anaerobic sulfate-reducing bacteria, anaerobic acid-producing bacteria, and aerobic
bacteria. These bacteria occur naturally and act to remove oil from an ecosystem.
Natural processes such as evaporation, oxidation, and biodegradation can start the oil spill cleanup
process but are generally too slow to provide adequate environmental recovery. Physical methods, such as
wiping with sorbent materials, pressure washing, and raking and bulldozing can be used to assist these
natural processes.
What was the Earth’s original source of free
atmospheric oxygen?
A. Oxygen produced from photosynthetic
marine algae
B. Breakdown of stratospheric ozone by
ultraviolet radiation
C. Chemosynthesis by bacteria
D. Photosynthesis by cyanobacteria
E. Release of oxygen from deep sea floor
vents and volcanoes
Answer: D
The earliest cells absorbed energy and food from the environment around them. They
used anaerobic fermentation, the breakdown of more complex compounds into less
complex compounds and used the energy to grow and reproduce. The evolution of
photosynthesis made it possible for cells to manufacture their own food.
Most of the life that covers the surface of the Earth depends directly or indirectly on
photosynthesis. The most common form, aerobic photosynthesis, turns carbon dioxide,
water, and sunlight into food. It captures the energy of sunlight in energy-rich molecules
such as ATP, which then provide the energy to make sugars. To supply the electrons in
the circuit, hydrogen is stripped from water, leaving oxygen as a waste product. Some
organisms, including purple bacteria and green sulfur bacteria, use a form of anaerobic
photosynthesis that use alternatives to hydrogen stripped from water as electron donors;
examples are hydrogen sulfide, sulfur, and iron. Such organisms are mainly restricted to
extreme environments such as hot springs and hydrothermal vents. These anaerobic
forms of life arose about 3.8 billion years ago.
At first, the released oxygen was bound up with limestone, iron, and other minerals.
The oxidized iron appears as red layers in geological strata called banded iron
formations. When most of the exposed readily reacting minerals were oxidized, oxygen
finally began to accumulate in the atmosphere. Though each cell only produced a minute
amount of oxygen, the combined metabolism of many cells over a vast time transformed
Earth’s atmosphere to its current state.
Photosynthesis had another major impact. Oxygen was toxic; much life on Earth
probably died out as its levels rose in what is known as the oxygen catastrophe. Resistant
forms survived and thrived, and some developed the ability to use oxygen to increase
their metabolism and obtain more energy from the same food.
Which two greenhouse gases found in the
Earth’s troposphere contribute most to the
greenhouse effect?
A. Carbon dioxide and water vapor
B. Carbon dioxide and methane
C. Carbon dioxide and ozone
D. Methane and ozone
E. Water vapor and ozone
Answer: A
A greenhouse gas is a gas in an atmosphere that absorbs and emits
radiation within the thermal infrared range. This process is the
fundamental cause of the greenhouse effect. The primary greenhouse
gases in the Earth's atmosphere are water vapor, carbon dioxide,
methane, nitrous oxide, and ozone.
Since the beginning of the Industrial Revolution, the burning of
fossil fuels has contributed to the increase in carbon dioxide in the
atmosphere from 280 to 397 ppm, despite the uptake of a large portion
of the emissions through various natural sinks involved in the carbon
cycle. Anthropogenic carbon dioxide emissions come from
combustion of carbon-based fuels, principally wood, coal, oil, and
natural gas.
When these gases are ranked by their direct contribution to the
greenhouse effect, the most important are Water vapor, which makes
up 36–72% of the contribution percentage, and Carbon dioxide, which
makes up 9–26% of the contribution percentage.
The primary source of fuel used in
households in developing countries is
A. oil
B. wood
C. crop residue
D. animal dung
E. grasses
Answer: B
For both the urban and rural poor in developing countries,
wood is usually the principal source of energy for cooking
food and for keeping warm. In these countries, an estimated
86% of all the wood consumed annually is used as fuel. As
populations have grown, this dependence has resulted in the
destruction of the forest. Wood fuels account for two-thirds
of all energy other than human and animal energy used in
Africa, for nearly one-third consumed in Asia, for one-fifth
in Latin America, and for 6% in the Near East. This
compares with the one-third of 1% of total energy use,
which wood fuels account for in developed countries.
About half of this wood fuel is used for cooking, about
one-third is used for heating the house, boiling water, etc.,
and the remainder is used for other domestic purposes, for
agricultural processing, and for industry.
Which layer of soil often
contains aluminum,
humus, iron, and clay
leached from higher soil
layers?
A. A
B. B
C. C
D. O
E. E
Answer: B
Eluviation is the process by which clay is removed from
topsoil, and illuviation is the process by which clay is deposited in
lower soil zones. Layer B, also known as subsoil, is the layer of soil
under the topsoil on the surface of the ground. It is the zone of
accumulation where rain water percolating through the soil has
leached material from above and where it has precipitated and
accumulated. Well-drained soils typically have the brightest colors
within the B horizons. Subsoil may include substances such as
sand, silt, and/or clay that have only been partially broken down by
air, sunlight, water, wind, etc., to produce true soil. Below the
subsoil is the substratum, which can be residual bedrock,
sediments, or deposits, largely unaffected by soil-forming factors
active in the subsoil. It contains partially weathered particles and
some microorganisms. It is usually a lighter shade of brown or
yellow. It contains the deeper roots of trees, but otherwise not much
lives here.
Which Kingdom listed below contains the
greatest number of species?
A. Monera, which includes unicellular and
colonial bacteria, including the true bacteria
and blue-green algae
B. Protista, which includes unicellular
protozoans and unicellular and multicellular
algae
C. Fungi
D. Plant
E. Animal
Answer: E
There are currently about 1.6 million species of living
organisms on Earth. This number may be much higher
because new species are continually being discovered
each day, particularly insects and nematodes in remote
tropical regions. Of this 1.6 million, there are about
10,000 different species of bacteria, 250,000 different
species of protists, 100,000 different species of fungi,
250,000 different species of plants, and about
1,000,000 different species of animals known at this
time. More than half of all animal species are insects
(800,000 species), and beetles (300,000 species)
comprise the largest order of insects (one-fifth of all
species on Earth).
Which groundwater contaminant listed below
does NOT result from the mining of coal?
I. Polychlorinated biphenyls (PCB)
II. Acid
III. Volatile organic compounds (VOC)
A. I only
B. II only
C. III only
D. I and III
E. I, II, and III
Countries undergoing rapid population
growth include which of the
following?
(A) I only
(B) II only
(C) III only
(D) II and III only
(E) I, II, and III
Approximately what percent of the
population in Country II is under age
15?
(A) 10 %
(B) 15%
(C) 20%
(D) 25 %
(E) 30%
Answer: D
When pyrite rocks (rocks containing iron sulfide,
FeS2) associated with coal mining are exposed to
oxygen, they react to generate acid mine drainage. The
chemical reactions are similar to geologic weathering,
which takes place over hundreds to thousands of
years, but the rates of reaction are orders of magnitude
greater than in "natural" weathering systems. The
accelerated reaction rates can release damaging
quantities of acidity, metals, and other soluble
components into the environment, and they may
ultimately seep into groundwater. The oxidation of
pyrite, which occurs in high-sulfur coal mining
operations, is among the most acid-producing of all
weathering processes in nature.
Which of the following conditions would
contain the most amount of water vapor in
a given volume of air?
A. 80oF at 10% relative humidity
B. 10oF at 80% relative humidity
C. 80oF at 80% relative humidity
D. 10oF at 10% relative humidity
E. 50oF at 80% relative humidity
Answer: C
Relative humidity describes the amount of
water vapor in a mixture of air and water vapor. It
is the ratio of the actual amount of water vapor in
a given volume of air to the amount that could be
present if the air were saturated at the same
temperature and is commonly expressed as a
percentage. With all other factors held constant,
warmer air can hold more water vapor than
cooler air. Generally, relative humidity doubles
with each 20°F decrease, or halves with each
20°F increase in temperature; therefore, as
temperature goes up, relative humidity goes
down and vice versa.
Which two air pollutants listed directly
cause the most deaths due to lung cancer
in the United States?
A. Tobacco smoke and asbestos
B. Tobacco smoke and occupational
exposure
C. Radon gas and ozone
D. Carbon monoxide and smog
E. Smog and ozone
Answer: B
Lung cancer is the leading cancer killer in both men and women in the
United States. In 1987, it surpassed breast cancer to become the leading
cause of cancer deaths in women, and it causes more deaths than the next
three most common cancers combined (colon, breast, and prostate).
It has been estimated that active smoking is responsible for close to 90%
of lung cancer cases; occupational exposures to carcinogens account for
approximately 9 to 15%, radon causes 10%, and outdoor air pollution 1 to
2%. Exposure to radon is a leading cause of lung cancer, accounting for an
estimated 15,000 to 22,000 lung cancer deaths each year. Radon is a
tasteless, colorless, and odorless gas produced by decaying uranium and
occurs naturally in soil and rock. The majority of these deaths occur among
smokers since there is a greater risk for lung cancer when smokers also are
exposed to radon.
Lung cancer can also be caused by occupational exposures, including
asbestos, uranium, and coke (an important fuel in the manufacture of iron in
smelters, blast furnaces, and foundries), although these percentages are likely
to decrease in the future due to awareness of the causes.
Almost one-third of the anthropogenic carbon
dioxide emitted into the atmosphere
A. is taken in by plants and converted to
oxygen through photosynthesis
B. is absorbed by the oceans
C. naturally decomposes in the presence of
ultraviolet radiation
D. remains in the atmosphere
E. combines with elements in the soil and is
captured in a variety of “sinks”
Answer: B
The global oceans are the largest natural reservoir for carbon dioxide, absorbing
approximately one-third of the carbon dioxide added to the atmosphere by human
activities each year. Over the next millennium, they are expected to absorb approximately
90% of the CO2 emitted to the atmosphere.
The Southern Ocean makes a substantial contribution to this oceanic carbon sink;
more than 40% of the anthropogenic carbon dioxide in the ocean has entered south of
40° S. The rate-limiting step in the oceanic sequestration of anthropogenic carbon dioxide
is the transfer of carbon across the base of the surface mixed layer into the ocean interior.
It is believed that dissolved CO2 in the ocean surface will double over its preindustrial value by the middle of this century, with accompanying surface ocean acidity
(pH) and carbonate ion (CO32-) decreases that are greater than those experienced during
the transition from ice ages to warm ages. The uptake of anthropogenic CO2 by the ocean
changes the chemistry of the oceans and can potentially have significant impacts on the
biological systems in the upper oceans.
Recent field and laboratory studies reveal that the carbonate chemistry of seawater
has a profound negative impact on the calcification rates of individual species and
communities in both planktonic (floating) and ocean bottom organisms. The effects of
decreased calcification in microscopic algae and animals could impact marine food webs
and, combined with other climatic changes in salinity, temperature, and upwelled
nutrients, could substantially alter the biodiversity and productivity of the ocean.
Which factor listed below is NOT a factor in
determining an ecological footprint?
I. Population size
II. Affluence
III. Level of technology
A. I only
B. II only
C. III only
D. II and III
E. All factors are used in determining an
ecological footprint
Answer: E
The ecological footprint is a measure of the human demand on the Earth's ecosystems. It is a
standardized measure of demand for natural capital that may be contrasted with the planet's capacity to
regenerate. It represents the amount of biologically productive land and sea area necessary to supply the
resources a human population consumes and to assimilate associated waste. Using this concept, it is
possible to estimate how much of the Earth (or how many planet Earths) it would take to support
humanity if everybody followed a given lifestyle. For 2007, humanity's total ecological footprint was
estimated at 1.5 planet Earths; that is, humanity uses ecological services 1.5 times as quickly as Earth can
renew them.
I = P × A × T is the formula that describe the impact of human activity on the environment, where
human impact (I) on the environment equals the product of population (P) × affluence (A) × technology
(T).
Increased population (P) increases environmental impacts, which include but are not limited to
increased land use, which results in habitat loss for other species;
increased resource use, which results in changes in land cover;
increased pollution, which causes climate change, sickens people , and damages ecosystems.
Affluence (A) represents the average consumption of each person in the population. As the
consumption of each person increases, the total environmental impact increases as well. A common tool
used for measuring consumption is through GDP per capita. Even though GDP per capita measures
production, it is often assumed that consumption increases when production increases and has been rising
steadily over the last few centuries and is driving up human impact on the environment.
Technology (T) represents how resource intensive the production of affluence is and how much
environmental impact is involved in creating, transporting, and disposing of the goods, services, and
amenities used. Improvements in efficiency can reduce resource intensiveness, reducing the effect of T.
For example, an appropriate unit for T might be greenhouse gas emissions per unit of GDP.
Including the external costs into the price
of a car is known as
A. optimum-cost pricing
B. cost-benefit pricing
C. added benefit pricing
D. external-cost pricing
E. full-cost pricing
Answer: E
An external cost occurs when producing or consuming a
good or service imposes a cost upon a third party. If there
are external costs in consuming a good (negative
externalities), the social cost will be greater than the private
cost. In the case of buying a car, driving a car imposes a
private cost on the driver (the cost of fuel, insurance,
maintenance, tax, and the car itself). However, driving a car
creates costs to other people in society. These costs can
include greater congestion and slower journey times for
other drivers; the cause of death for pedestrians, cyclists,
and other road users; and pollution and other health-related
problems. Including these social costs into the cost of the car
instead of paying for social costs through higher taxes is
known as full-cost pricing.
A pipeline ruptured and released an industrial
chemical into a lake. The initial concentration
of the pollutant was measured at 50 ppm. If
the pollutant dissipates by 20% every 7 days ,
what would the concentration of the pollutant
in the lake water be after 14 days?
A. 45 ppm
B. 40 ppm
C. 32 ppm
D. 16 ppm
E. 4 ppm
The pollutant is initially at a concentration
of 50 ppm. After 7 days, 20% of the 50
ppm would have dissipated (0.50 × 20
ppm = 10 ppm); therefore, the
concentration would be 50 original – 10
dissipated = 40 left. After another 7 days,
20% of the 40 ppm would have
dissipated; therefore, the concentration
would be 40 ppm – 8 ppm = 32 ppm.
Which action listed below would be the most effective
in reducing the emissions of carbon dioxide gas in the
United States?
A. Switching from burning coal to produce electricity to
using alternative methods of producing energy such as
wind, solar, etc.
B. Switching from gasoline and diesel engines to
hybrids or battery-driven vehicles
C. Planting millions of trees
D. Charging a large tax on the usage of electricity
produced from burning coal
E. Installing large air pumps to blow air through filters
and ocean water to sequester and trap CO2
Answer: A
Carbon dioxide (CO2) is the primary greenhouse gas emitted through human
activities. Carbon dioxide emissions in the United States increased by about 12%
between 1990 and 2010 and accounts for about 84% of all U.S. greenhouse gas emissions
from human activities, and CO2 emissions in the United States are projected to grow by
about 1.5% between 2005 and 2020. The main human activity that emits CO2 is the
combustion of fossil fuels (coal, natural gas, and oil) for energy and transportation,
although certain industrial processes and land-use changes also emit CO2.
The combustion of fossil fuels to generate electricity is the largest single source of
CO2 emissions in the United States, accounting for about 40% of total U.S. CO2
emissions and 33% of total U.S. greenhouse gas emissions. The type of fossil fuel used to
generate electricity will emit different amounts of CO2. To produce a given amount of
electricity, burning coal will produce more CO2 than will oil or natural gas.
The combustion of fossil fuels such as gasoline and diesel is the second largest source
of CO2 emissions, accounting for about 31% of total U.S. CO2 emissions and 26% of
total U.S. greenhouse gas emissions. This category includes transportation sources such
as highway vehicles, air travel, marine transportation, and rail.
Various industrial processes account for about 14% of total U.S. CO2 emissions and
20% of total U.S. greenhouse gas emissions.
Planting trees alone, without reducing the burning of fossil fuels, does not solve the
problem of CO2 emission, and many areas (i.e., arid areas) may not be suitable for tree
planting. Charging a large tax on energy that generates CO2 gas disproportionately
penalizes those on low or fixed incomes. Removing CO2 from the atmosphere and
putting it into the oceans--- well, you know that one!
Most of the world’s earthquakes occur
A. in the middle of continents
B. along the edges of continents or
tectonic plates
C. in the open oceans
D. on islands
E. during volcanic eruptions
Answer: B
The world's earthquakes are not randomly distributed over the Earth's surface but tend to be
concentrated in specific areas. The distribution of earthquakes is explained by the theory of plate
tectonics, which combines many of the ideas about continental drift and sea-floor spreading.
According to the theory of plate tectonics, the Earth's rigid outer shell (lithosphere) is broken into a
mosaic of constantly moving oceanic and continental plates that slide over the uppermost layer of
the mantle known as the asthenosphere. They interact along their margins, where one plate is forced
under the other and where geological processes take place, such as the formation of mountain belts,
earthquakes, and volcanoes.
Plate tectonics confirms that there are four types of seismic zones:
The first follows the boundaries of mid-ocean ridges where the plates are pulled apart and
where the lithosphere is very thin and weak, so the strain cannot build up enough to cause large
earthquakes. Earthquake activity here is low, and it occurs at very shallow depths. An example of
this area would be Iceland.
The second type of earthquake is the shallow-focus event unaccompanied by volcanic activity.
In these faults, two mature plates are scraping past each other. The friction between the plates can
be so great that very large strains can build up before they are periodically relieved by large
earthquakes. The San Andreas Fault is a good example of this.
The third type of earthquake is related to the collision of oceanic and continental plates. One
plate is thrust or subducted under the other plate so that a deep ocean trench is produced. Ocean
trenches are associated with curved volcanic island arcs on the landward plate. An example occurs
near the Java trench.
The fourth type of seismic zone occurs along the boundaries of continental plates. Within this
zone, shallow earthquakes are associated with high mountain ranges where intense compression is
taking place. Intermediate- and deep-focus earthquakes also occur. Examples of these types of
earthquakes occur in the Himalayan Mountains.
A sample of radioactive waste has a halflife of 10 years and an activity level of 2
curies. After how many years will the
activity level of this sample be 0.25 curie?
(A) 10 years
(B) 20 years
(C) 30 years
(D) 40 years
(E) 80 years
Which of the following is NOT an example of
a point source of pollution?
A. Water pollution from an oil refinery
wastewater discharge outlet
B. Noise pollution from a jet engine
C. Agricultural runoff containing a high level
of nitrogen
D. Light pollution from an intrusive street light
E. Thermal pollution from a nuclear power
plant
51
Answer: C
Point source pollution is related to emissions that can be easily identified as
coming from a single discharge source.
Agricultural operations account for a large percentage of all nonpoint source
pollution in the United States. When large tracts of land are plowed to grow crops, it
exposes and loosens soil that was once buried. This makes the exposed soil more
vulnerable to erosion during rainstorms. It also can increase the amount of fertilizer
and pesticides carried into nearby bodies of water.
To control sediment and runoff, farmers may utilize erosion controls to reduce
runoff flows and retain soil on their fields. Common techniques include
implementing contour plowing, crop mulching, crop rotation, perennial crops, and
riparian buffers. Conservation tillage is a concept used to reduce runoff while
planting a new crop. With this technique, the farmer leaves some crop reside from
the previous planting in the ground to help prevent runoff during the planting
process.
Nutrients (nitrogen and phosphorus) are typically applied to farmland as
commercial fertilizer; animal manure; or spraying of municipal or industrial
wastewater (effluent) or sludge. Nutrients may also enter runoff from crop residues,
irrigation water, wildlife, and atmospheric deposition. Farmers can develop and
implement nutrient management plans to reduce excess application of nutrients.
Which of the following statements would be TRUE
regarding the following age structure diagrams?
I. A would be typical for a developing country, while B
would be typical for a developed country.
II. A has a population that is declining, while B has a
population that is expanding.
III. A would be typical for a country like Japan, while B
would be typical for a country like Mexico.
A. I only
B. II only
C. III only
D. II and III
E. I and III
52 Answer: A
A population pyramid, also called an age structure diagram, is a
graphical illustration that shows the distribution of various age
groups in a population (typically that of a country or region of the
world). When the population is growing, it forms the shape of a
pyramid. It is also used to determine the overall age distribution of
a population; an indication of the reproductive capabilities and
likelihood of the continuation of a species.
It typically consists of two back-to-back bar graphs, with the
population plotted on the X-axis and age on the Y-axis, one
showing the number of males and one showing females.
The age structure diagram for Mexico, a developing country,
shows the unmistakable pyramidal shape caused by ever-increasing
number of births.
Japan’s diagram, which is typical for developed countries, has
the classic shape of a shrinking population. Note how prereproductive age groups (0–14 years) have smaller populations than
the reproductive age groups (15–44 years).
Mitigation of overgrazing includes all of the
following techniques EXCEPT
A. using rotational grazing schedules
B. selecting proper breeds of cattle that work best
with the natural ecology and resources
C. planting warm-season perennial grasses such as
switchgrass
D. applying lime and organic fertilizer to the
rangeland
E. increasing the size of the herds to optimize profit
53 Answer: E
Sustainable pasture management practices, which include a balance of
matching forage and livestock resources, managing resources, proper breed
selection, and looking for alternative feeds, can help to reduce the effects of
overgrazing.
Properly managed grazing can have some benefits. Cattle manure
fertilizes pastures. In addition, grazing can encourage re-growth and prevent
the spread of noxious weeds. Ranchers have found that cattle hooves break
up ground that left alone would be too hard for seeds to penetrate. Ranchers
using this system have been able to double the carrying capacity of their
pastures. Also they have a higher percentage of perennial grasses (which
produce more biomass) as ground cover than land ranched conventionally.
Properly managed grazing maintains healthy vegetation, which helps to
filter pollutants from runoff, reduce runoff velocity, and control soil erosion.
Management practices that help to maintain vegetative cover involve
distributing cattle so that they do not overgraze portions of pasture and
allowing for recovery of the vegetation following a grazing period.
Adjusting the stocking rate seasonally, particularly in sensitive
watershed areas, can also reduce the impacts of overgrazing.
Environmental consequences of hydraulic
fracturing, also known as "fracking,"
include all of the following EXCEPT
A. blowouts and explosions
B. major spills
C. atmospheric emissions of toxic gases
D. land subsidence
E. decrease in cost of electricity
54 Answer: E
Hydraulic fracturing or "fracking" is the
process of utilizing pressurized water, chemical
additives, and physical proppants (materials that
will keep a fracture open) to fracture rock layers
and release petroleum, natural gas, or other
substances so that they can be extracted.
Environmental risks associated with this
technology include contamination of
groundwater, risks to air quality, the potential
migration of gases and hydraulic fracturing
chemicals to the surface, the potential
mishandling of waste, and health effects.
In the food web, the owl is a
I. Primary consumer
II. Secondary consumer
III. Tertiary consumer
A. I only
B. II only
C. III only
D. II and III
E. I, II and III
55 Answer: D
Consumers are organisms receive their energy by consuming
other organisms. These organisms are also referred to as
heterotrophs, which include animals, bacteria and fungus. Such
organisms may consume by various means, including predation,
parasitization, and biodegradation.
Within an ecological food chain, consumers are categorized
into three groups: primary consumers, secondary consumers, and
tertiary consumers. Primary consumers are usually herbivores,
feeding on plants and fungus (e.g. the squirrel or rabbit feeding
only on plant material). Secondary consumers prey on the
primary consumers (e.g. the owl feeding on the squirrel).
Omnivores feed on both plants and animals (e.g. the bird feeding
on either plants or insects). Tertiary consumers feed on
secondary consumers (e.g. owl → mouse → insect → plants).
If the autotrophs or producers in the
diagram received 1000 Kcal of solar
energy, how much energy will be left for
the owl if the owl consumed a mouse?
A. 1 Kcal
B. 10 Kcal
C. 100 Kcal
D. 700 Kcal
E. 1000 Kcal
56 Answer: A
Generally, each trophic level relates to the one below it by absorbing and
using some of the energy it consumes for its own needs. When a food
chain is diagrammed to illustrate the amount of energy that moves from
one feeding level to the next, it is called an energy pyramid.
The efficiency with which energy or biomass is transferred from one trophic
level to the next is called the ecological efficiency. Consumers at each
level convert on average only about 10% of the chemical energy in their
food to their own organic tissue. For this reason, food chains rarely
extend for more than five or six levels. At the lowest trophic level (the
bottom of the food chain or food pyramid), plants convert only about 1%
of the sunlight they receive into chemical energy. Therefore, for every
1,000 Kcals of energy that is initially trapped in plants (autotrophs), only
100 Kcals of that energy will be ultimately available to the next higher
level or primary consumers (i.e. insects); with 10% of that or 10 Kcals of
energy being available to the mice; and only 1 Kcal of that energy
ultimately being available for the owl. It follows then, that the owl needs
to eat a lot of mice in order to staisfy its nutritional requirement, and that
any particular environment can only support a limited number of tertiary
A 5-MW wind turbine can produce 15 million
kWh of electrical energy in a year. The average
U.S. household consumes about 10,000 kWh of
electricity each year. If a company wishes to
install 50 of these 5-MW wind turbines on a
proposed wind farm, how many households can
be supported in one year?
A. 5,000
B. 7,500
C. 25,000
D. 50,000
E. 75,000
57
Which of the following pollutants would
NOT be classified as a persistent organic
pollutant (POP)?
A. Dioxin
B. Polychlorinated biphenyl (PCBs)
C. DDT
D. Chlordane
E. Mercury
58 Answer: E
Persistent organic pollutants (POPs) are organic compounds (contain
carbon) that are resistant to environmental degradation through chemical,
biological, and photolytic processes. Because of this, they have been
observed to persist in the environment, be capable of long-range transport,
bioaccumulate in human and animal tissue, biomagnify in food chains, and
have potential significant impacts on human health and the environment.
Many POPs are currently or were in the past used as pesticides. Others
are used in industrial processes and in the production of a range of goods
such as solvents, polyvinyl chloride, and pharmaceuticals. There are a few
natural sources of POPs, but most POPs are created by humans in
industrial processes.
POP exposure can cause death and illnesses including disruption of the
endocrine, reproductive, and immune systems; neurobehavioral disorders;
and cancers possibly including breast cancer. Exposure to POPs can take
place through diet, environmental exposure, or accidents.
The element mercury (Hg), although toxic and a pollutant, is not organic
as it does not contain the element carbon.
Which of the following actions would lead to an
increase in biodiversity?
I. Reducing or eliminating invasive species
II. Introducing and maintaining invasive species
III. Decreasing the pH of acid rain
A. I only
B. II only
C. III only
D. I and III
E. I, II, and III
59 Answer: A
Between 50 and 150 species become extinct daily, a level 10,000 times
greater than the natural rate of species extinction. The main drivers of
biodiversity loss are deforestation, desertification, overexploitation,
invasive species, pollution, and climate change. For a species to become
invasive, it must successfully out-compete native organisms, spread
through its new environment, increase in population density, and harm
ecosystems in its introduced range.
Common characteristics of invasive species include rapid reproduction
and growth, high dispersal ability, ability to adapt to new conditions, and
ability to survive on various food types and in a wide range of
environmental conditions. A good predictor of invasiveness is whether a
species has successfully or unsuccessfully invaded elsewhere.
Ecosystems that have been invaded by alien species may not have the
natural predators and competitors present in its native environment that
would normally control their populations. Native ecosystems that have
undergone human-induced disturbance are often more prone to alien
invasions because there is less competition from native species.
Acid rain becomes more acidic when the pH decreases.
Which of the following is NOT a property of
water?
A. Water has the ability to filter out UV light
B. Water is a solvent, allowing many
chemicals to dissolve in it
C. When water freezes into ice, it expands
D. Water can change its temperature very
quickly
E. Water has the ability to filter out red light
60 Answer: D
Water has a very high specific heat capacity
as well as a high heat of vaporization both of
which are a result of the extensive hydrogen
bonding between its molecules. These two
unusual properties allow water to moderate
Earth's climate by buffering or resisting large
fluctuations in temperature. The oceans
absorb one thousand times more heat than the
atmosphere and hold 80 to 90% of the heat
due to global warming.
According to the graph, the increase in
CO2 concentration, in parts per million,
between 1970 and 1990 is closest to
(A) 5 ppm
(B) 30 ppm
(C) 50 ppm
(D) 340 ppm
(E) 355 ppm
Which of the following most
directly explains the periodic
fluctuations of the curve?
(A) Daily variations in air temperature
(B) Daily variations in sea level
(C) Seasonal variations in photosynthetic activity
(D) Seasonal variations in ocean water temperature
(E) Seasonal variations in human industrial activity
Which of the following would be
considered a form of low-quality energy?
A. natural gas
B. wind power
C. gasoline
D. nuclear fission
E. coal
61 Answer: B
Energy quality can be thought of as
energy density. The less energy that is
contained in a given volume, the lower its
energy quality. When fossil fuels were
created millions of years ago, solar energy
was converted into chemical energy and
then concentrated into small volumes.
This gives these fuels a high energy
density, thus high-quality energy.
Which of the following is NOT an
anthropogenic source of atmospheric
sulfur?
A. oil refining
B. using gasoline and diesel fuel
C. smelters to produce a metal from its ore
D. decay of organic material
E. incineration of municipal wastes
62 Answer: D
The term "anthropogenic" designates an effect or object resulting from human activity. Most of the sulfur on Earth is stored
in oceans, sedimentary rocks, and air particles (during evaporation). A very small percentage reaches the surface and exchanges
with atmosphere.
Sulfur is the 13th most abundant element in the Earth’s crust (0.1%) and the 9th most abundant in sediments. Sulfur content
of rocks varies considerably; for example, sedimentary rocks have about 0.38%, while igneous rocks have only 0.032%. Sulfur
in the lithosphere is mobilized by the slow weathering of rock material. Dissolved in runoff, it moves with river water and is
deposited in continental shield sediments in oceans. Eventually on the geological timescale, this uplifts to the surface again thus
completing the geological part of the sulfur cycle.
Several sulfur compounds listed below are released into the atmosphere due to interaction of processes between the Earth’s
surface and the atmosphere.
1. Carbonyl sulfide (COS): Carbonyl sulfide is the most abundant sulfur species in the atmosphere and is mainly produced
by the decomposition processes in soil, in marshes and wetlands, and along ocean coasts and areas of ocean upwelling that are
rich in nutrients. Oceans may act both as the source and the sink of COS. About 80% of total atmospheric sulfur is COS, but it is
relatively inert and does not add much to the atmospheric sulfur pollution.
2. Carbon disulfide (CS2): Carbon disulfide is far more reactive than COS and has similar sources as carbonyl sulfide. It has
a lifetime of 12 days only and its major sink is photochemical reactions. The most important source of the compound is
microbial processes in warm tropical soils. Major secondary sources are marshes and wetlands along sea coasts with small
anthropogenic inputs from fossil fuel combustion.
3. Dimethyl sulfide (DMS): Dimethyl sulfide is released from oceans in much greater amounts than COS or CS2 and is very
rapidly oxidized to sulfur dioxide (SO2). Its concentrations are high during night, particularly in areas under some influence from
continental sources.
4. Hydrogen sulfide (H2S): Hydrogen sulfide is produced in nature during anaerobic decay in soils, wetlands, salt marshes,
and other areas of stagnant water with maximum concentrations occurring in tropical forests. Its highest concentrations occur at
night and in early morning when photochemical activity is at a minimum.
5. Sulfur dioxide (SO2): Sulfur dioxide is released during the oxidation of H2S, which is emitted during the combustion of
fossil fuels. In some industrialized areas such as eastern North America, more than 90% of SO 2 is from anthropogenic sources.
About 50% of SO2 is removed from the atmosphere by wet and dry deposition.
6. Sulfate aerosols (SO42−): Sulfate aerosol particles originate from sea spray and are one of the largest natural sources of
sulfur to the atmosphere. Most of the salt spray sulfate falls back to oceans, but some is carried over the continents to be
included in other deposition processes.
Which of the following are characteristics of
organisms that reproduce asexually?
I. They tend to grow in number exponentially.
II. They rely on mutation in their DNA for
variation(s).
III. The large amount of variation in their genes
makes them less susceptible to disease.
A. I only
B. II only
C. III only
D. I and II
E. I, II, and III
63 Answer: D
The known methods of reproduction are broadly grouped into two main types: sexual
and asexual. In asexual reproduction, an individual can reproduce without involvement
with another individual of that species (e.g., division of a bacterial cell into two daughter
cells). Sexual reproduction typically requires the involvement of two individuals or
gametes, one from each sex.
Advantages of asexual reproductive strategies include:
1. Large numbers of offspring are reproduced very quickly from only one parent when
conditions are favorable.
2. Large colonies can form that can outcomplete other organisms for nutrients and water.
3. Large number of organisms mean that species may survive when conditions or the
number of predators change.
4. Energy is not required to find a mate
Disadvantages of asexual reproductive strategies include:
1. Offspring are genetic clones. A negative mutation can make asexually produced
organisms susceptible to disease and can destroy large numbers of offspring.
2. Some methods of asexual reproduction produce offspring that are close together and
complete for food and space.
3. Unfavorable conditions (i.e., extreme temperatures) can wipe out entire colonies.
Which of the following are environmental
consequences of overfishing?
I. Resource depletion
II. Increased biological growth rates
III. Lower biomass levels
A. I only
B. II only
C. III only
D. I and III
E. I, II, and III
64 Answer: D
Overfishing is the act whereby fish stocks are depleted to unacceptable levels,
regardless of water body size. Resource depletion, low biological growth rates, and
critical low biomass levels result from overfishing. The ability of a fishery to recover
from overfishing depends on whether the ecosystem's conditions are suitable for the
recovery.
Dramatic changes in species composition can result in an ecosystem shift. For
example, once trout have been overfished, carp might take over in a way that makes it
impossible for the trout to reestablish a breeding population.
There are three forms of overfishing:
1. Growth overfishing occurs when fish are harvested at an average size that is smaller
than the size that would produce the maximum yield, which makes the total yield less
than it would be if the fish were allowed to grow to an appropriate size. It can be
countered by reducing fishing mortality to lower levels and increasing the average size of
harvested fish to a size that will allow maximum yield.
2. Recruitment overfishing occurs when the mature adult population is depleted to a level
where it no longer has the reproductive capacity to replenish itself. This can be mitigated
by placing moratoriums, quotas, and minimum-size limits on a fish population.
3. Ecosystem overfishing occurs when the balance of the ecosystem is altered by
overfishing. With declines in the abundance of large predatory species, the abundance of
small forage type increases causing a shift in the balance of the ecosystem toward smaller
fish species.
Sulfur dioxide in the presence of
suspended air particulates produces
human health effects often greater than
can be accounted for by exposure to either
pollutant alone. This effect is known as
A. bioaccumulation
B. biomagnification
C. cross contamination
D. synergism
E. trophic magnification
65 Answer: D
One of the best known sulfur-related pollution episodes took
place in London December 5–9, 1952, when high
concentrations of air pollution were trapped to the ground
due to specific weather conditions at the time. Because of
the cold winter, Londoners were burning more low-quality,
high-sulfur coal to heat their homes. The combination of
sulfur oxides along with particulates and other air pollutants
resulted in more than 4,000 deaths and another 8,000 in the
months that followed; far more deaths than can be accounted
for by exposure to any of the pollutants alone. Many deaths
were due to respiratory tract infections from hypoxia (low
levels of oxygen in the blood) and due to the obstruction of
air passages from lung infections resulting from the SO2
being exposed to and trapped in lung tissues by the polluting
air particles.
How much time will be required for a
sample of tritium 3H to lose 75% of its
radioactivity? The half-life of tritium is
12.26 years.
A. 3.07
B. 6.13
C. 12.26
D. 24.52
E. 36.78
66 Answer: D
If 75% is lost, then 25% (or 0.25) remains.
(1/2)n = 0.25
12.26 × 2 = 24.52 years
n=2
An alternative way to solving the problem is
(1/2)n = 0.25
n log 0.5 = log 0.25
n = log 0.25 / log 0.5
n=2
Tritium, 3H, is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two
neutrons, whereas the nucleus of normal hydrogen 1H, contains one proton and no neutrons. Naturally
occurring tritium is extremely rare on Earth, where trace amounts are formed by the interaction of the
atmosphere with cosmic rays.
The emitted electrons from the radioactive decay of small amounts of tritium cause phosphors to glow
so as to make self-powered lighting devices, which are now used in firearm night sights, watches, exit
signs, map lights, and a variety of other devices and takes the place of radium, which can cause bone
cancer. Tritium is also an important component in nuclear weapons and is used to enhance the efficiency
and yield of fission bombs.
Tritium is also an important fuel for research in controlled nuclear fusion.
Which of the following is most likely to be
the direct result of lack of genetic diversity in
a food crop such as corn?
(A) Decreased kernel size
(B) Decreased potential yield
(C) Decreased dependence on chemical
fertilizers
(D) Increased susceptibility to plant disease
(E) Increased resistance to pests
Global warming can cause all of the
following EXCEPT
A. a rise of sea levels
B. the lowering of the pH of the oceans
C. increased temperature stratification in
the oceans
D. increased volcanic activity
E. increased ozone destruction
67Answer: E
Two main factors have contributed to observed sea level rise. The first is thermal expansion: as
ocean water warms, it expands. The second is from the contribution of land-based ice due to
increased melting.
As carbon dioxide dissolves in sea water, carbonic acid is formed, which has the effect of
acidifying the ocean (lowering the pH). Future ocean acidification and climate change would impair
a wide range of marine organisms and the effects rippling through the marine food webs.
Global warming will increase the temperature of surface waters first. Ocean water circulation
patterns have far-reaching effects on global climate. Convective mixing is a dominant process due
to thermal stratification of the water column. At low latitudes, warm, low-density surface waters
float over a mass of much colder, high-density subsurface water. As warm surface water travels
north, the temperature difference between surface and subsurface is diminished. Nutrient-depleted
surface water cools and sinks, forcing deep water to rise. As deep water rises to the ocean surface, it
brings a fresh pulse of nutrients that causes enhanced ocean productivity near the poles.
The retreat of glaciers and ice caps has the potential of increasing volcanism. Reduction in ice
cover reduces the confining pressure exerted on the volcano, increasing stresses, and potentially
causing the volcano to erupt. This reduction of pressure can also cause decompression melting of
material in the mantle, resulting in the generation of more magma. The effects of current sea level
rise could also include increased crustal stress at the base of coastal volcanoes from a rise in the
volcano's water table and the associated saltwater intrusion, while the mass from extra water could
activate dormant seismic faults around volcanoes. In addition, the wide-scale glacier melting is
likely to slightly alter the Earth's rotational period and may shift its axial tilt creating further crustal
stress changes.
Global warming and ozone depletion are independent phenomenon
Which Act established a system for controlling
hazardous wastes from the time it was generated
until its ultimate disposal (i.e., "cradle to grave")?
A. Comprehensive Environmental Response,
Compensation, and Liability Act (Superfund)
B. National Environmental Policy Act (NEPA)
C. Pollution Prevention Act (PPA)
D. Resource Conservation and Recovery Act
(RCRA)
E. Toxic Substances Control Act (TOSCA)
68 Answer D
The Resource Conservation and Recovery Act
(RCRA), enacted in 1976, is the principal federal law
in the United States governing the disposal of solid
waste and hazardous waste. Congress enacted RCRA
to address the increasing problems the nation faced
from its growing volume of municipal and industrial
waste. RCRA set national goals for
Protecting human health and the natural
environment from the potential hazards of waste
disposal.
Reducing the amount of waste generated, through
source reduction and recycling
Ensuring the management of waste in an
environmentally sound manner.
Which Act tracks industrial chemicals
currently produced in or imported to the
United States?
A. Comprehensive Environmental Response,
Compensation, and Liability Act
(Superfund)
B. National Environmental Policy Act
(NEPA)
C. Pollution Prevention Act (PPA)
D. Resource Conservation and Recovery Act
(RCRA)
E. Toxic Substances Control Act (TOSCA)
69 Answer: E
The Toxic Substances Control Act (TOSCA) passed by
the United States Congress in 1976 regulates the
introduction of new or already existing chemicals.
TOSCA does not separate chemicals into categories of
toxic and non-toxic but instead prohibits the manufacture
or importation of chemicals that are not on its list.
Manufacturers must submit premanufacturing notification
to the U.S. Environmental Protection Agency (EPA) prior
to manufacturing or importing new chemicals for
commercial purposes. New chemical notifications are
reviewed by the EPA, and if it finds an "unreasonable risk
to human health or the environment," it may limit its use(s)
or production volume to outright banning them.
Which Act established a trust fund to provide
for cleanup when a responsible party or
company could not be identified?
A. Comprehensive Environmental Response,
Compensation, and Liability Act
(Superfund)
B. National Environmental Policy Act
(NEPA)
C. Pollution Prevention Act (PPA)
D. Resource Conservation and Recovery Act
(RCRA)
E. Toxic Substances Control Act (TOSCA)
70 Answer: A
Superfund is the common name for the
Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA),
a federal law designed to clean up sites contaminated
with hazardous substances. Superfund provides broad
federal authority to clean up releases or threatened
releases of hazardous substances that may endanger
public health or the environment. The law authorized
the Environmental Protection Agency (EPA) to
identify parties responsible for contamination of sites
and compel the parties to clean up the sites. Where
responsible parties cannot be found, the Agency is
authorized to clean up sites itself, using a special trust
fund.
A U-shaped body of water formed when a
wide meander from the main stem of a river
is cut off over time as erosion and deposits of
soil change the river's course is known as a(n)
A. eutrophic lacke
B. oxbow lake
C. oligotrophic lake
D. mesotrophic lake
E. crater lake
71 Answer: B
As a mature river begins to curve, it cuts and
erodes into the outside of the curve and deposits
sediment on the inside of the curve since the
stream moves more rapidly on the outside of the
curve and more slowly on the inside of the curve.
Thus, as the erosion and deposition continues, the
curve becomes larger and more circular.
Eventually the river begins to cut the loop off by
eroding the neck of the loop and the river breaks
through at a cutoff and forms a new streambed.
Sediment is then deposited on the loop side of the
stream, cutting off the loop from the stream
entirely.
Elements that cycle in the environment and that
also have a gaseous phase at some point in their
cycle include which of the following?
I. Carbon
II. Phosphorus
III. Sulfur
(A)
(B)
(C)
(D)
(E)
I only
III only
I and II only
I and III only
I, II, and III
Which of the examples listed below
would be a positive externality?
A. Air pollution from fossil fuels
B. Industrial farm animal production
C. The cost of storing nuclear waste
D. Renewable energy
E. Widespread use of antibiotics
72 Answer: D
A negative externality (also called "external cost") is an action of a product on
consumers that imposes a negative side effect on a third party; it is "social cost." Many
negative externalities are related to the environmental consequences of production and use.
Air pollution from burning fossil fuels causes damages to crops, (historic) buildings, and
public health.
Industrial farm animal production, on the rise in the 20th century, resulted in farms that
were easier to run, with fewer and often less-skilled employees, and a greater output of
uniform animal products. However, the externalities with these farms include contributing
to the increase in the pool of antibiotic-resistant bacteria because of the overuse of
antibiotics; air quality problems; the contamination of rivers, streams, and coastal waters
with concentrated animal waste; and animal welfare problems, mainly as a result of the
extremely close quarters in which the animals are housed.
The cost of storing nuclear waste from nuclear plants for more than 1,000 years (over
100,000 for some types of nuclear waste) is included in the cost of the electricity the plant
produces in the form of a fee paid to the government and the long-term risks of disposal of
chemicals, which may remain permanently hazardous.
Antibiotic use contributes to antibiotic resistance, reducing the future effectiveness of
antibiotics.
Renewable energy may create positive externalities as it reduces net environmental
pollution.
Which of the following is least likely to be
affected by global warming?
I. K-strategists
II. r-strategists
III. Keystone species
A. I only
B. II only
C. III only
D. II and III
E. I, II, and III
73 Answer: B
In unstable or changing environments, r-selection predominates
as the ability to reproduce quickly is crucial. Traits that are
characteristic of r-selection include high fecundity, small body size,
early maturity onset, short generation time, and the ability to
disperse offspring widely. Organisms who exhibit r-selected traits
include bacteria, insects, weeds, and small rodents.
A keystone species is a species that has a disproportionately
large effect on its environment relative to its abundance. Such
species play a critical role in maintaining the structure of an
ecological community, affecting many other organisms in an
ecosystem and helping to determine the types and numbers of
various other species in the community. Since keystone species can
be either K-strategists (e.g., sea otters) or r-strategists (e.g., the
herbivorous milfoil weevil insect, Euhrychiopsis lecontei); no
correlation can be drawn as to global warming and its effect on
keystone species.
Which of the following treaties, Acts, or
Protocols addressed international trade in
endangered species?
A. Montreal Protocol
B. Kyoto Protocol
C. London Protocol
D. CITES
E. Endangered Species Act
74 Answer: D
CITES (Convention on International Trade in
Endangered Species of Wild Fauna and Flora) is a
multilateral treaty adopted in 1963 at a meeting of
members of the International Union for Conservation
of Nature (IUCN) and entered into force in 1975. Its
aim is to ensure that international trade in specimens
of wild animals and plants does not threaten the
survival of the species in the wild, and it accords
varying degrees of protection to more than 5,000
species of animals and 29,000 species of plants.
The Endangered Species Act is a law of the United
States and does not regulate international trade in
endangered species.
Which of the following events occur during an El
Niño?
I. Oceanic surface temperatures along the North
and South American coasts become cooler.
II. Upwellings of cold, nutrient-rich water are
suppressed.
III. Prevailing easterly winds weaken.
A. I only
B. II only
C. III only
D. I and II
E. I, II, and III
75 Answer: B
One of the oceanic processes altered during an El Niño year is upwelling, or the
rising of deeper colder water to shallower depths off the western coast of Peru—one of
the world’s richest fisheries. Because of the frictional stresses that exist between ocean
layers, surface water is transported at a 90 degree angle to the left of the winds in the
Southern Hemisphere. Winds blowing northward and parallel to the coastline of Peru
located in the Southern Hemisphere "drag" oceanic surface water away from the shore.
As a result, nutrient-rich water rises from deeper levels to replace the surface water that
has drifted away. It is these nutrients that are responsible for supporting the large fish
population commonly found in the coastal areas off Peru.
However, the effectiveness of upwelling and its ability to support abundant marine
life is greatly dependent upon the depth of the thermocline, which is the transition layer
between the mixed layer at the surface and the deep water layer. The boundaries of these
layers are based on water temperature.
The mixed layer is near the surface where the temperature is roughly that of surface
water. In the thermocline, the temperature decreases rapidly from the mixed layer
temperature to the much colder deep water temperature.
The mixed layer and the deep water layer are relatively uniform in temperature,
while the thermocline represents the transition zone between the two.
However, a deeper thermocline (often observed during El Niño years) limits the
amount of nutrients brought to shallower depths by upwelling processes, which greatly
reduces the year's fish crop.
Individuals of the same species
occupying a given area at the same
time is known as a
A. group
B. population
C. community
D. cluster
E. niche
76 Answer: B
A population is a group of individuals of the
same species occupying a particular
geographic area. Populations may be
relatively small and closed, as on an island or
in a valley, or they may be more diffuse and
without a clear boundary between them and a
neighboring population of the same species.
For species that reproduce sexually, the
members of a population may interbreed
either exclusively with members of their own
population or with members of other
populations.
Which of the following examples listed
below is NOT an ecosystem service?
A. Detoxifies pollutants
B. Performs pest and disease control
C. Provides food (including seafood and
game), crops, wild foods, and spices
D. Manages carbon sequestration and
climate regulation
E. All are examples of ecosystem services
77 Answer: E
Humankind benefits from a multitude of
resources and processes that are supplied by
natural ecosystems. Collectively, these benefits
are known as ecosystem services and include
products like clean drinking water and processes
such as the decomposition of wastes.
Ecosystem services can be separated into four
broad categories: (1) provisioning, such as the
production of food and water; (2) regulating, such
as the control of climate and disease; (3)
supporting, such as nutrient cycles and crop
pollination; and (4) cultural, such as spiritual and
recreational benefits.
Which of the following statements is in accord with
The Tragedy of the Commons?
I. Larger "commons" result in more personal
responsibility.
II. Smaller "commons" result in greater personal
responsibility.
III. The size of the "commons" has nothing to do
with personal responsibility.
A. I only
B. II only
C. III only
D. I and III
E. I, II, and III
78 Answer: B
The Tragedy of the Commons was written by ecologist Garrett Hardin
and first published in the journal Science in 1968.The tragedy of the
commons is a dilemma arising from the situation in which multiple
individuals, acting independently and rationally consulting their own selfinterest, will ultimately deplete a shared limited resource, even when it is
clear that it is not in anyone's long-term interest for this to happen.
The Tragedy of the Commons involves medieval land tenure in Europe,
focusing on herders who share a common parcel of land on which they are
each entitled to let their cows graze. It is in each herder's interest to put the
next (and succeeding) cows he acquires onto the land, even if the quality of
the common is damaged for everyone through overgrazing. The herder
receives all of the benefits from an additional cow, while the damage to the
common is shared by the entire group. If all herders make this individually
rational economic decision, the common will be depleted or even
destroyed, to the detriment of all. Hardin also cites modern examples,
including the overfishing of the world's oceans and ranchers who graze
their cattle on government lands.
Most of the world’s proven coal
deposits are found in
A. China
B. Russia
C. United States
D. Canada
E. Ukraine
79 Answer: C
Estimates show that there are about 1,000 billion tons of
proven and recoverable coal reserves (~ 4,000 billion barrels of
oil equivalent) left on Earth, which would last about another 150
years. Projections predict that global peak coal production may
occur sometime around 2025 at 30% above current production,
depending on future coal production rates.
Of the three fossil fuels (coal, oil, and natural gas), coal has the
most widely distributed reserves; coal is mined in over 100
countries, and on all continents except Antarctica. The largest
reserves are found in the United States, Russia, and China.
Country
Total
Percent of World Total
United State
237,295
22.6%
Russia
157.010
14.4%
China
114,500
12.6%
The Environmental Protection Agency has
responsibilities in all of the following
areas EXCEPT
A. resource conservation
B. water pollution
C. waste disposal
D. air pollution
E. noise pollution
80 Answer: A
The U.S. Environmental Protection Agency (EPA), an agency of
the U.S. federal government, was created for the purpose of
protecting human health and the environment by writing and
enforcing regulations based on laws passed by Congress.
Resource conservation falls under the jurisdiction of the
National Resource Conservation Service (NRCS), which was
originally established by Congress in 1935 as the Soil Conservation
Service. NRCS has expanded to become a conservation leader for
all natural resources, ensuring private lands are conserved, restored,
and more resilient to environmental challenges (i.e., climate
change).
Seventy percent of all land in the United States is owned
privately. The NRCS works with private landowners through
conservation planning and assistance designed to benefit the soil,
water, air, plants, and animals and so effect productive lands and
healthy ecosystems.
The land on a 100-acre farm is equally suited for
grazing cattle and growing com. Of the
following ways of distributing land use, which
would produce the greatest number of calories
for human consumption?
Acres for
Grazing Cattle
(A) 100
(B) 80
(C) 50
(D) 20
(E) 0
Acres for
Growing Corn
0
20
50
80
100
Which of the following substances listed
is NOT a teratogen?
A. smog
B. benzene
C. drinking alcohol
D. tobacco
E. X-rays
81 Answer A
Teratogens are substances or environmental agents that cause the
development of abnormal cell masses during fetal growth, resulting
in physical defects in the fetus. The World Health Organization
estimates that about 50% of all fertilized ova are lost within the
first three weeks of development, that 15% of all clinically
recognizable pregnancies end in spontaneous abortions, and that
birth defects are known to occur in 3 to 6% of all newborns. They
are the leading cause of infant mortality in the United States,
accounting for more than 20% of all infant deaths. Seven to ten
percent of all children will require extensive medical care to
diagnose or treat a birth defect. It is extremely difficult to make
accurate estimates of exposure risk due to the large number of
pharmaceutical, industrial, and agricultural chemicals, which
increase the risk of exposure to multiple agents and their potential
synergistic effects, and human genetic heterogeneity, which
contributes greatly to the individual level of threshold
susceptibility. Smog has not been shown to be a teratogen.
The largest percent of domestic water use
in the United States is used for
A. bathing and showering
B. watering lawns and gardens
C. toilets
D. cooking and drinking
E. agriculture
82 Answer: B
Domestic use includes water used around
the home. Up to 50% of household
water goes toward outdoor use, and an
estimated 50% of that is lost due to
evaporation or landscape runoff due to
overwatering.
An APES class is doing soil studies and
determines that a sample of soil contains 30%
clay, 20% silt, and 50% sand. Using the soil
texture chart above, the soil would be
classified as
A. silt, clay loam
B. sandy, clay loam
C. loamy sand
D. silt loam
E. sandy loam
83 Answer: B
The population in 1970 of a small mid-Western town
was 35,000. The birth rate was measured at 20 per
1,000 population per year, while the death rate was
measured at 5 per 1,000 population per year. People
moving into the town were measured at 350 per year
while those leaving the town were measured at 100
per year. By how much did the population increase (or
decrease) in 1970?
A. increased by 300
B. decreased by 775
C. increased by 775
D. increased by 1,200
E. increased by 1,200
84 Answer: C
Population Change
= (Crude Birth Rate + Immigration) –
(Crude Death Rate) + Emigration
= [20(35) + 350] – [5(35)] + 100
= +775
Which of the following types of public lands
would mining of natural mineral resources NOT
be allowed on?
I. National Forests
II. National Resource Lands
III. National Wilderness Preservation System
A. I only
B. II only
C. III only
D. I and II
E. I, II, and III
85 Answer: C
Multiple Use Lands
1. National Forest System: managed by the U.S. Forest Service; used for
logging, mining, livestock grazing, farming, oil and gas, recreation, sport
hunting, and wildlife resources.
2. National Resource Lands: managed by the Bureau of Land Management;
used for supply of domestic energy, minerals, and livestock grazing (with
permit).
Moderately Restricted Use Lands
3. National Wildlife Refuges: managed by the U.S. Fish and Wildlife
Service; used for protecting habitats, breeding grounds, sport hunting,
fishing, oil and gas extraction, mining, logging, grazing, and farming.
Restricted Land Use
4. National Park System: managed by the National Park Service; used for
camping, hiking, sport fishing, and boating.
5. National Wilderness Preservation System: managed by National Park
Service, Forest Service, U.S. Fish and Wildlife Service, and the Bureau of
Land Management; used for recreational activities only.
Which of the following is NOT a primary
air pollutant from burning coal?
A. Carbon monoxide
B. Particulate matter
C. Ozone
D. Sulfur dioxide
E. Nitrogen oxides
86 Answer: C
Burning coal generates 54% of the electricity generated in the United States and is the
single largest air polluter. Burning coal is a leading cause of smog, acid rain, global
warming, and air toxics. In an average year, a typical coal plant generates:
• 3,700,000 tons of carbon dioxide (CO2), the primary human cause of global
warming—as much carbon dioxide as cutting down 161 million trees.
• 10,000 tons of sulfur dioxide (SO2), which causes acid rain that damages forests,
lakes, and buildings and forms small airborne particles that can penetrate deep into
lungs.
• 500 tons of particulate matter, which can cause chronic bronchitis, aggravated asthma,
and premature death.
• 10,200 tons of nitrogen oxide (NOx), which leads to the formation of ozone. Ozone
inflames the lungs, burning through lung tissue making people more susceptible to
respiratory illness. However, burning coal does NOT directly release significant
amounts of ozone.
• 720 tons of carbon monoxide (CO), which causes headaches and places additional
stress on people with heart disease.
• 220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone.
• 170 pounds of mercury, which is so toxic that just 1/70th of a teaspoon (about the size
of a drop) of mercury deposited in a 25-acre lake will make the fish unsafe to eat.
• 225 pounds of arsenic.
• 114 pounds of lead, 4 pounds of cadmium, other toxic heavy metals, and trace amounts
of uranium.
Keystone species are species that
A. have the largest populations in a
community
B. occupy the highest niche in an ecosystem
C. play a critical role in maintaining the
structure of an ecological community
D. form the base of the food pyramid in an
ecosystem
E. are the most sensitive to and affected by
environmental degradation
87 Answer: C
A keystone species is a species that has a disproportionately large effect on its
environment relative to its abundance. Such species play a critical role in maintaining the
structure of an ecological community, affecting many other organisms in an ecosystem
and helping to determine the types and numbers of various other species in the
community. The role that a keystone species plays in its ecosystem is analogous to the
role of a keystone in an arch. While the keystone is under the least pressure of any of the
stones in an arch, the arch still collapses without it. Similarly, an ecosystem may
experience a dramatic shift if a keystone species is removed, even though that species
was a small part of the ecosystem by measures of biomass or productivity.
An example of a keystone species are sea otters, that live in the kelp forests off the
coast of California. Sea otters are mammals who feed on a variety of marine invertebrates
but who feed especially on sea urchins. Sea urchins are voracious herbivores that tend to
feed on the base of the kelp, eating through the stipe until the whole plant detaches from
the bottom and floats away. An overabundance of urchins can lead to overgrazing of the
kelp forest. Once abundant in California, sea otters were hunted down for their pelts from
a population of around 16,000 to near extinction. The resulting effect on the kelp forest
was an increase in the barren areas because of the urchin populations. After they were
placed under federal protection to increase their numbers and save them from extinction,
sea otters were able to begin naturally controlling the urchins so that the kelp forests had
a chance to recover.
A small, healthy lake had a dissolved oxygen (DO) content
reading of 1 mg/L. A break in a major sewage line nearby
spilled thousands of gallons of raw sewage into the lake.
The DO content of the lake after the spill should
A. decrease as bacteria count increases and consumes DO
B. decrease since sewage would provide nutrients for fish
living in the lake and more fish would use more oxygen
C. increase due to added amount of nutrients introduced into
the lake, which would increase the rate of photosynthesis
of aquatic plants
D. increase due to the added amount of oxygen and other
gases released during the decay process
E. should no change, as long as the sewage would remain
dissolved
88 Answer: A
Eutrophication is the ecosystem response to the addition of artificial or natural
substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic
system.
Following are ecological effects that can arise from eutrophication:
• Decreased biodiversity
• Changes in species composition and dominance
• Toxicity effects
• Increased biomass of phytoplankton
• Toxic or inedible phytoplankton species
• Increases in blooms of gelatinous zooplankton
• Increased biomass of benthic and epiphytic algae
• Changes in macrophyte species composition and biomass
• Decreases in water transparency (increased turbidity)
• Color, smell, and water treatment problems
• Dissolved oxygen depletion
• Increased incidences of fish kills
• Loss of desirable fish species
• Reductions in harvestable fish and shellfish
• Decreases in perceived aesthetic value of the water body
Which of the following characteristics do
NOT contribute to extinction?
A. Low reproductive rate
B. Specialized feeding patterns
C. Fixed migratory patterns
D. Preys on livestock or people
E. Offspring are small in size
Areas of low air pressure are typically
characterized by __________ air and
move toward areas where the air pressure
is ____________.
A. rising decreasing
B. sinking, increasing
C. rising, increasing
D. sinking, decreasing
E. sinking, not changing
90 Answer: A
A low pressure system, or "low," is an area where the atmospheric
pressure is lower than that of the area surrounding it. Lows are usually
associated with high winds, warm air, and atmospheric lifting. Because of
this, lows normally produce clouds, precipitation, tropical storms, and
cyclones. In addition, areas prone to low pressure do not have extreme
diurnal (day vs. night) and seasonal temperatures because the clouds present
over such areas reflect incoming solar radiation back into the atmosphere. As
a result, under a low pressure system, the days are cooler and the nights are
warmer.
Conversely, a high pressure system, or "high," is an area where the
atmospheric pressure is greater than that of the surrounding area. High
pressure areas are normally caused by a phenomenon called subsidence,
meaning that as the air in the high cools it becomes denser and moves toward
the ground. Pressure increases here because more air fills the space left from
the low. Subsidence also evaporates most of the atmosphere's water vapor so
high pressure systems are usually associated with clear skies and calm
weather. Unlike areas of low pressure, the absence of clouds means that areas
prone to high pressure experience extremes in diurnal and seasonal
temperatures since there are no clouds to block incoming solar radiation or
trap outgoing longwave radiation at night. Thus, such areas have higher high
temperatures and lower low temperatures.
Examine the diagram below of a
demographic transition model. Currently,
the United States would be in what stage?
A. 1
B. 2
C. 3
D. 4
E. 5
91 Answer: D
Demographic transition refers to the
transition from high birth and death rates
to low birth and death rates as a country
develops from a pre-industrial to an
industrialized economic system. This is
typically demonstrated through a
demographic transition model.
The most rapidly growing renewable
energy source since 1995 has been
A. hydropower
B. wind
C. solar
D. geothermal
E. nuclear
92 Answer: B
Renewable energy currently accounts for about 7% of
U.S. energy consumption. Most of that comes from biomass
and hydroelectric sources. Since 1995 the amount of energy
produced by renewable sources has increased by 16%.
The most rapidly growing renewable energy source since
1995 has been wind power with the implementation of wind
power increasing more than 2000%. Although this is very
large growth, wind contributes less than 1% of the energy
supply in the United States.
Solar has grown more than 55% since 1995 and the rapid
fall in the per-kilowatt price of solar panels should support
future growth. Geothermal has grown nearly 27%. New
technologies and higher fossil fuel prices now make
geothermal space heating projects cost competitive with
fossil fuel units.
The release of methylmercury into the
environment and the effect of its
bioaccumulation occurred near this city.
A. Bhopal, India
B. Chernobyl, Ukraine
C. Love Canal, New York
D. Minimata, Japan
E. Three Mile Island, Pennsylvania
93 Answer: D
Minamata disease is a neurological syndrome caused by
severe mercury poisoning. Symptoms include ataxia,
numbness in the hands and feet, general muscle weakness,
narrowing of the field of vision, and damage to hearing and
speech. In extreme cases, insanity, paralysis, coma, and
death follow within weeks of the onset of symptoms.
Minamata disease was first discovered in Minamata, Japan,
in 1956 and was caused by the release of methylmercury in
the industrial wastewater from the Chisso Corporation's
chemical factory, which continued from 1932 to 1968. This
highly toxic chemical bioaccumulated in shellfish and fish
in Minamata Bay which when eaten by the local populace
resulted in mercury poisoning, resulting in 2,265 victims,
1,784 of whom died.
The building of a residential community
on land that contained 21,000 tons of
buried toxic chemicals occurred in this
city.
A. Bhopal, India
B. Chernobyl, Ukraine
C. Love Canal, New York
D. Minimata, Japan
E. Three Mile Island, Pennsylvania
94 Answer: C
Love Canal was a neighborhood in Niagara Falls, New
York. In the mid-1970s Love Canal became the subject of
national and international attention after it was revealed that
the site had formerly been used to bury 21,000 tons of toxic
waste by Hooker Chemical Company.
The construction of the housing development combined
with particularly heavy rainstorms over time released the
chemical wastes into the environment. As a result of the
buried chemicals, high rates of unexplained illnesses,
nervous disorders, cancers, miscarriages, birth defects, and
mental retardation were common in the area. A survey
conducted by the Love Canal Homeowners Association
found that 56% of the children born from 1974 to 1978 had
at least one birth defect.
Approximately what percentage of the
world’s population lives in developing
countries?
A. less than 5%
B. 25%
C. 50%
D. 80%
E. 95%
95 Answer: D
The development of a country is measured with such
factors as income per person, gross domestic or
national product, life expectancy, the rate of literacy,
and the availability of health care. Developing, also
known as less- or least-developed countries, are in
general countries that have not achieved a significant
degree of industrialization relative to their populations
and that have, in most cases, a medium to low
standard of living; examples include Egypt, the
Philippines, and Mexico. They include countries with
a low living standard, undeveloped industrial base,
and low Human Development Index (HDI) relative to
other countries. There is also a strong correlation
between low income and high population growth
Which of the following choices below shows the
correct order for the stages of succession for a
temperate deciduous forest?
A. Perennial plants and grasses  annual plants
 shrubs  pines  hardwood trees
B. Annual plants and grasses  perennial plants
 shrubs  pines  hardwood trees
C. Annual plants  perennial plants and grasses
 shrubs  pines  hardwood trees
D. Perennial plants  grasses  annual plants 
shrubs  pines  hardwood trees
E. Grasses  annual plants  perennial plants
 shrubs  pines  hardwood trees
96 Answer: C
Ecological succession is the process by which an ecological community undergoes orderly
and predictable changes following a disturbance or initial colonization of new habitat. Succession
that begins in new habitats, not influenced by pre-existing communities is called primary
succession, whereas succession that follows disruption of a pre-existing community is called
secondary succession. Physical factors that determine the nature of the community that develops in
an area are temperature, the amount of rainfall, soil type, and the amount of sunlight reaching the
plants.
Temperate deciduous forests occur south of the taiga in the Northern Hemisphere. They grow
in areas with a growing season between 140 and 300 days and with 30–60 inches (75–150 cm)
rain/year.
They have a complex understory with some species (particularly smaller species) flowering in
the spring before the canopy leafs out. For animals in a temperate forest, nuts (seeds of the
dominant trees) are an important food source. Many of the food chains in the temperate deciduous
forest, however, are detritus based. Many organisms depend on nutrients and energy released from
the leaves that drop to the forest floor each fall (annual leaf fall before the cold season is a
characteristic of the temperate deciduous forest). While the soil is rich, more of the nutrients are tied
up in the trees, to be released when the trees die.
Pioneer species (annuals) that produce large quantities of seeds and that are disseminated by
the wind are able to colonize large empty areas. They are capable of growing under direct sun
exposition and are the first to inhabit vacant areas in the temperate deciduous forests. Once these
plants have produced a closed canopy, the lack of direct sunlight at the soil level makes it difficult
for their own seedlings to develop. It is then that the opportunity for more shade-tolerant species
such as perennials and grasses can become established. When these more shade-tolerant plants die,
the even more shade-tolerant shrubs and trees begin to replace them in kind. The shade-tolerant
species are capable of growing under the canopy and, therefore, in the absence of catastrophes, will
stay. At this point, the community has reached its climax. When another catastrophe arrives
destroying the climax community, the opportunity for the pioneer species will be open once again.
The "heat island effect" is most
associated with
A. desert
B. islands
C. cities
D. rural areas
E. stratospheric warming
97 Answer: C
An (urban) heat island is a metropolitan area, which is significantly
warmer than its surrounding rural areas. The temperature difference usually
is larger at night than during the day and is most apparent when winds are
weak. Seasonally, it is seen during both summer and winter. The main cause
of the urban heat island is modification of the land surface by urban
development, which uses materials that effectively retain heat. Waste heat
generated by energy usage is a secondary contributor. As a population center
grows, it tends to expand its area, and increase in its average temperature.
Monthly rainfall is greater downwind of cities, partially due to the heat
island effect. Increases in heat within urban centers increases the length of
growing seasons and decreases the occurrence of weak tornadoes. It also
decreases air quality by increasing the production of pollutants such as ozone
and decreases water quality as warmer waters flow into area streams.
Mitigation of the urban heat island effect can be accomplished through
the use of light-colored roofs and the use of lighter-colored surfaces in urban
areas, which reflect more sunlight and absorb less heat.
Which type of radiation does the
stratospheric ozone layer entirely
block?
A. UV-A
B. UV-B
C. UV-C
D. Infrared
E. Gamma
98 Answer: C
The stratospheric ozone layer is a layer in the Earth's atmosphere
containing about 10 parts ozone per million parts air, with the average ozone
concentration in Earth's atmosphere being about 0.6 parts per million parts
air. The ozone layer is mainly found in the lower portion of the stratosphere
from approximately 12–19 miles (20–30 km) above the Earth, though the
thickness varies seasonally and geographically. Although the concentration
of the ozone in the ozone layer is very small, it is vitally important to life
because it absorbs biologically harmful ultraviolet (UV) radiation coming
from the sun. Extremely short UV radiation is divided into three categories
based on its wavelength and are referred to as UV-A (400–315 nm), UV-B
(315–280 nm), and UV-C (280–100 nm). UV-C, which would be very
harmful to all living things, is entirely screened out by stratospheric ozone.
Some UV-B radiation does penetrate the ozone layer and reaches the Earth’s
surface. UV-B can be harmful to the skin and is the main cause of sunburn
and skin cancer and excessive exposure can even cause genetic damage. The
intensity of UV-B radiation at the top of the stratosphere is 350 million times
stronger than at the Earth’s surface.
Ozone is transparent to most UV-A, so most of this longer wavelength,
lower energy ultraviolet radiation does reach the Earth’s surface. UV-A is
significantly less harmful to DNA than UV-B, although it may still
potentially cause indirect genetic damage in skin.
Which method below tries to mimic a basic
function of economic markets by setting an
economic standard for measuring the success
of environmental projects and/or programs?
A. External cost analysis
B. Marginal cost analysis
C. Cost-benefit analysis
D. Sustainable cost analysis
E. Risk analysis
99 Answer: C
Cost-benefit analysis provides an organizational framework for identifying,
quantifying, and comparing the costs and benefits (measured in dollars) of a proposed
(environmental) policy action. The final decision is informed (though not necessarily
determined) by a comparison of the total costs and benefits.
Cost-benefit analysis has two purposes:
To determine if it is a sound investment/decision (justification/feasibility) and
To provide a basis for comparing projects. It involves comparing the total expected
cost of each option against the total expected benefits, to see whether the benefits
outweigh the costs, and by how much.
The following steps that comprise a generic cost-benefit analysis:
• List alternative projects/programs.
• List stakeholders.
• Select measurement(s) and measure all cost and benefits elements.
• Predict outcome of cost and benefits over relevant time period.
• Convert all costs and benefits into a common currency.
• Calculate net present value of project options.
• Adopt recommended choice.
• Measure the effects on users or participants.
• Measure externality effects.
• Measure the social benefits.
During the December solstice, the
sun is directly overhead at the
A. North Pole
B. South Pole
C. equator
D. Tropic of Cancer
E. Tropic of Capricorn
100 Answer: E
The December solstice occurs between December 20th
and December 23rd. It is at a time when the North Pole is
tilted 23.5° away from the sun. On this date, all places above
66.5° north latitude (Arctic Polar Circle) are in darkness,
while locations below latitude of 66.5° south (Antarctic
Polar Circle) receive 24 hours of daylight. The sun is
directly overhead on the Tropic of Capricorn in the Southern
Hemisphere during the December solstice. It also marks the
longest day of the year in terms of daylight hours for those
living south of the equator.
For an observer in the Northern Hemisphere, the
December solstice marks the day of the year with the least
hours of daylight. Those living or traveling north of the
Arctic Circle toward the North Pole will not be able to see
the sun during this time of the year.