Archive for September 2017

One of the promises made by the government in 1994 was "free electricity." Since 2003 the government has provided a small amount of electricity free to each household. Beyond that, a household must pay for the electricity that it uses. Many people would prefer a flat-rate pricing system, where each household throughout greater Johannesburg would pay the same rate each month. This would mean that ________.

Naim 03:45 Add Comment

One of the promises made by the government in 1994 was "free electricity." Since 2003 the government has provided a small amount of electricity free to each household. Beyond that, a household must pay for the electricity that it uses. Many people would prefer a flat-rate pricing system, where each household throughout greater Johannesburg would pay the same rate each month. This would mean that ________.



A) all households in Johannesburg would be able to have all the electricity that they need
B) Eskom, the electric company, would probably make huge profits in Soweto
C) wealthy households would end up paying much more and have less electricity than they do now
D) there would not be enough electricity left to provide service to poor households
E) with less incentive to keep electric usage low, environmental issues related to the generation of electricity would worsen




Answer: E

Other than in downtown Johannesburg, the worst air pollution in the region in the year 2000 was in Soweto. The probable explanation is that in downtown Johannesburg ________, while in Soweto ________.

Naim 03:44 Add Comment

Other than in downtown Johannesburg, the worst air pollution in the region in the year 2000 was in Soweto. The probable explanation is that in downtown Johannesburg ________, while in Soweto ________.



A) coal-fired electrical plants were the cause; automobile traffic in overcrowded areas was the problem
B) automobile traffic was the cause; automobile traffic was also the cause
C) automobile traffic was the cause; the burning of fuels in each home for heating, light, and cooking was the major contributor to indoor and outdoor air pollution
D) gasoline-powered electrical generators were the cause; trash incinerators were a problem
E) trash incinerators were a problem; gasoline-powered electrical generators were the cause




Answer: C

Along with many other governmental reforms that began in 1994, the electrical plant just outside Soweto was closed in 2000, and other plants were brought into use. Some parts of Soweto were then wired for electricity. It is estimated, however, that only about 30% of the more than 1 million black inhabitants have electricity in their homes; the remainder either cannot afford the costs involved or live in areas that have no electrical access. These inhabitants probably use ________ for fuel.

Naim 03:44 Add Comment

Along with many other governmental reforms that began in 1994, the electrical plant just outside Soweto was closed in 2000, and other plants were brought into use. Some parts of Soweto were then wired for electricity. It is estimated, however, that only about 30% of the more than 1 million black inhabitants have electricity in their homes; the remainder either cannot afford the costs involved or live in areas that have no electrical access. These inhabitants probably use ________ for fuel.




A) natural gas and solar cells
B) natural gas and backyard windmills
C) charcoal and candles
D) wood and coal
E) gas-powered home generators




Answer: D

The heavy levels of soot from the electrical plant upwind of Soweto, along with dust from gigantic mine dumps from gold and coal mines, created particulate pollution more than three times the recommended level. This would be expected to result in ________.

Naim 03:43 Add Comment

The heavy levels of soot from the electrical plant upwind of Soweto, along with dust from gigantic mine dumps from gold and coal mines, created particulate pollution more than three times the  recommended level. This would be expected to result in ________.



A) high levels of heart disease
B) increased incidence of lung disease
C) high levels of birth defects
D) problems with running local automobiles and other machinery
E) enriched agricultural fields and increased crop yields



Answer: B

The fact that there is a high sulfur content in the coal burned in South African power plants means that the ________.

Naim 03:43 Add Comment

The fact that there is a high sulfur content in the coal burned in South African power plants means that the ________.



A) power plants contribute to acid deposition
B) power plants burn cleanly, with little pollution
C) power plants emit high levels of radioactive pollution
D) coal is very inexpensive, leading to an improved economy
E) coal is very expensive, forcing most poor people to go without electricity




Answer: A

One of the conclusions that can be drawn from this scenario is that ________.

Naim 03:41 Add Comment

One of the conclusions that can be drawn from this scenario is that ________.



A) cattle improved the soils, contributing to this ecosystem.
B) predators were unimportant components of this ecosystem; their removal caused no subsequent problems.
C) prairie dogs were unimportant components of this ecosystem; their removal caused no subsequent problems.
D) once humans change one thing in an ecosystem, they may find unexpected results occurring elsewhere in the ecosystem.
E) prairie dogs were part of a negative feedback loop once they were removed.




Answer: D

How do the prairie dogs in this story meet the definition of a keystone species?

Naim 03:41 Add Comment

How do the prairie dogs in this story meet the definition of a keystone species?





A) They don't meet the definition of a keystone species; the system did fine without them. The predators turned to cattle, and the grasses did better in the compact soil.
B) Their burrows loosened the soil and served as homes for other species; they helped with nutrient recycling. They helped water infiltrate into the soil and kept soil loose for grass roots. When they were removed, the system deteriorated.
C) The availability of prairie dogs kept the predators in check; when they were removed, the predator populations grew dramatically. They kept the soil aerated and compact.
D) When the prairie dogs were removed, the cattle declined; this meets the definition of a keystone species.
E) Their burrows caused cattle to break their legs and die. This made them directly responsible for the welfare of another species, which meets the definition of a keystone species.


Answer: B

Once the prairie dogs were poisoned and no longer a part of the ecosystem, which of the following probably occurred?

Naim 03:41 Add Comment

Once the prairie dogs were poisoned and no longer a part of the ecosystem, which of the following probably occurred?



A) Soils slowly became looser because of the cattle, so soil moisture increased.
B) Soils slowly compacted because of the cattle, decreasing infiltration of moisture into the soil.
C) Soils slowly became looser because of the cattle, so fewer nutrients were recycled.
D) Soils slowly compacted because of the cattle, increasing infiltration of moisture into the soil.
E) Soils slowly became looser because of the cattle, decreasing infiltration of moisture into the soil.



Answer: B

In the late 1800s and early 1900s farmers and ranchers slaughtered coyotes, bobcats, wolves, mountain lions, eagles, and rattlesnakes, trying to protect their cattle. One direct result may have been ________.

Naim 03:40 Add Comment

In the late 1800s and early 1900s farmers and ranchers slaughtered coyotes, bobcats, wolves, mountain lions, eagles, and rattlesnakes, trying to protect their cattle. One direct result may have  been ________.



A) a decrease in soil quality
B) an increase in predation
C) an increase in soil quality
D) an increase in the prairie dog population
E) a decrease in the prairie dog population



Answer: D

When the rains came down on the rocky mountainsides, the water ran down into the grasslands where the prairie dogs were active and ________.

Naim 03:40 Add Comment

When the rains came down on the rocky mountainsides, the water ran down into the grasslands where the prairie dogs were active and ________.



A) quickly ran off the loose soil, eroding the soil
B) quickly evaporated, drying the loose soil
C) quickly soaked into the loose soil, watering the grasses
D) gathered atop the loose soil, forming large muddy spots
E) formed ponds




Answer: C

Prairie dog activities probably contribute to ________.

Naim 03:40 Add Comment

Prairie dog activities probably contribute to ________.



A) the grass roots being subject to diseases
B) the soil being loose and to little nutrient cycling, causing grasses to fall over
C) the soil hardening during rains and to little nutrient cycling, causing grasses to die
D) the localized extinction of prairie grasses
E) the soil being loose and to nutrient cycling, allowing new grass roots to grow and prosper




Answer: E

Global warming has been hypothesized to cause many plants to flower earlier. If bees search for food earlier in response to this, this would represent ________ within the community.

Naim 03:39 Add Comment

Global warming has been hypothesized to cause many plants to flower earlier. If bees search for food earlier in response to this, this would represent ________ within the community.




A) primary succession
B) secondary succession
C) coevolution
D) climax
E) extirpation




Answer: B

Which of the following is likely to have occurred after 1923?

Naim 03:38 Add Comment

Which of the following is likely to have occurred after 1923?



A) The deer population continued to increase exponentially until 2002.
B) The government has continued the ban on deer hunting and has continued killing cougars and coyotes that immigrate into the preserve.
C) The deer overgrazed their environment, decreasing the carrying capacity of the habitat.
D) The deer population crashed, and no deer have been seen in the preserve since 1947.
E) The preserve was invaded by Eurasian collared doves in 1988.



Answer: C

The initial population of Kaibab deer in 1906 was about 4000. In an area of about 800,000 acres, this works out to an average density of one deer per 200 acres. What is the density in 1923?

Naim 03:38 Add Comment

The initial population of Kaibab deer in 1906 was about 4000. In an area of about 800,000 acres, this works out to an average density of one deer per 200 acres. What is the density in 1923?



A) one deer per 20 acres
B) one deer per 500 acres
C) one deer per 80 acres
D) one deer per 8 acres
E) one deer per 0.8 acre




Answer: D

The removal of the livestock and predators, and the cessation of hunting in 1907 ________.

Naim 03:38 1 Comment

The removal of the livestock and predators, and the cessation of hunting in 1907 ________.




A) increased the carrying capacity for the Kaibab deer
B) decreased the carrying capacity for the Kaibab deer
C) removed the limits on immigration, allowing more deer into the area
D) decreased r, allowing more births among Kaibab deer
E) increased r, allowing more births among Kaibab deer



Answer: A

Which of the following describes a graph of the Kaibab deer population between 1900 and 1923?

Naim 03:37 Add Comment

Which of the following describes a graph of the Kaibab deer population between 1900 and 1923?



A) a straight line slanting upward, showing a steady increase over time
B) a J-shaped upward curve with a very rapid increase
C) a "sine wave" curving up, down, up, down
D) a rapidly decreasing slope from left to right
E) an S-shaped curve that shows a smooth, rapid increase and then levels off





Answer: D

Positive feedback loops destabilize environmental systems by creating a "snowball effect," whereby a change in the system causes further change. Which of the following represents a positive feedback loop in regard to global warming?

Naim 03:37 Add Comment

Positive feedback loops destabilize environmental systems by creating a "snowball effect," whereby a change in the system causes further change. Which of the following represents a positive feedback loop in regard to global warming?



A) warming of Earth, increasing the evaporation of surface water
B) reforestation, causing a release of carbon dioxide from soil microbes
C) controlling development, resulting in higher population densities in urban centers
D) limiting use of fossil fuels as a source of energy
E) sequestering carbon dioxide underground, resulting in a drop in atmospheric carbon dioxide levels



Answer: A

Why does burning fossil fuels contribute to global warming?

Naim 03:37 Add Comment

Why does burning fossil fuels contribute to global warming?




A) Fossils, if left untouched, cool Earth.
B) New energy is created on Earth when fossil fuels are burned.
C) Burning fossil fuels creates increased plate tectonic movement.
D) Carbon present in coal, oil, and natural gas becomes carbon dioxide when these fuels burn.
E) Burning fossil fuels removes water vapor from the atmosphere.




Answer: D

Overpopulation contributes to global warming when ________.

Naim 03:36 Add Comment

Overpopulation contributes to global warming when ________.




A) most of the population is vegetarian
B) it leads to deforestation, increased agriculture, and increased use of fossil fuels
C) we compromise our living standards in order to protect the environment
D) most people use public transportation
E) solar energy is used as the primary source of energy, since it is a renewable resource





Answer: B

Besides contributing to global warming, nitrous oxide contributes indirectly to acid precipitation because of ________.

Naim 03:36 Add Comment

Besides contributing to global warming, nitrous oxide contributes indirectly to acid precipitation because of ________.



A) its ability to form compounds that raise pH
B) its ability to form compounds that lower pH
C) the ability of acids to raise the temperature of the substances which dissolve them
D) the airborne nature of all compounds containing nitrogen
E) the hydrogen bonds connecting the nitrogen and oxygen atoms in the molecule





Answer: B

Which of the following is the most logical explanation for water being a greenhouse gas?

Naim 03:36 Add Comment

Which of the following is the most logical explanation for water being a greenhouse gas?



A) The ionic bonds holding water vapor together help it trap heat.
B) Hydrogen-containing compounds trap the most heat, and water contains hydrogen.
C) Water is a good conductor of electricity, and electricity contains heat.
D) The hydrogen bonds holding molecules of water vapor together help it trap heat.
E) Water is acidic, and acids retain heat.




Answer: D

Between 1995 and 2000, ________.

Naim 03:35 Add Comment

Between 1995 and 2000, ________.



A) coal consumption decreased
B) fossil fuel use stabilized
C) oil consumption exceeded nuclear, hydropower, and biomass combined
D) natural gas consumption increased rapidly
E) there was a clear trend of movement from nonrenewable to renewable energy resources



Answer: C

Which of the following statements is true?

Naim 03:34 Add Comment

Which of the following statements is true?



A) The majority of electricity used in the United States is produced using imported fuels.
B) Nuclear energy is never used either directly or indirectly for transportation in the United States.
C) Energy derived from coal is never used for transportation in the United States.
D) Less than half of natural gas used in the United States is used to generate electricity.
E) In the United States, more electricity is produced using natural gas than coal.



Answer: D

The graph illustrates ________.

Naim 03:31 Add Comment

The graph illustrates ________.




A) marginal benefit and cost curves
B) the costs of resource use and pollution reduction
C) internal and external costs associated with market economies
D) how price is determined by supply and demand
E) how price falls when demand is high




Answer: D

The intersection of the two lines (the middle of the "X") on the graph represents ________.

Naim 03:31 Add Comment

The intersection of the two lines (the middle of the "X") on the graph represents ________.



A) the maximum price buyers will pay for goods and services
B) the minimum price buyers will pay for goods and services
C) the maximum quantity of goods and services that a company can produce
D) the minimum quantity of goods and services that a company can produce
E) market equilibrium



Answer: E

Hydrogen bonds connect ________.

Naim 03:31 Add Comment

Hydrogen bonds connect ________.




A) hydrogen atoms to oxygen atoms within the water molecule
B) oxygen atoms to other oxygen atoms
C) positive regions of one water molecule to negative regions of other water molecules
D) hydrogen atoms to other hydrogen atoms
E) the nuclei of adjacent water molecules



Answer: D

Why are both ends of each water molecule positive and the middle negative?

Naim 03:30 Add Comment

Why are both ends of each water molecule positive and the middle negative?



A) Oxygen has a greater pull on the electrons.
B) Oxygen has a greater pull on the protons.
C) The two hydrogens present have a greater pull on the electrons.
D) The two hydrogens present have a greater pull on the protons.
E) Hydrogen bonds create a charge difference.



Answer: A

Which would result in the highest rate of evolution?

Naim 03:10 Add Comment

Which would result in the highest rate of evolution?



A. a rapidly changing environment

B. a population with high genetic diversity

C. a long generation time

D. few variations of phenotypes and genotypes

E. drastic changes to the environment



Answer: B

Which pair would most increase the rate of evolution within a species?

Naim 03:10 Add Comment

Which pair would most increase the rate of evolution within a species?



A. slow environmental change and high genetic variation

B. rapid environmental change and large population change

C. long generation times and low genetic variation

D. large population size and slow environmental change

E. short generation time and small population size




Answer: A

Which is not related to geographic isolation?

Naim 03:09 Add Comment

Which is not related to geographic isolation?



A. the founder effect

B. A population separated into two by a natural disturbance.

C. allopatric speciation

D. sympatric speciation

E. an island colonized by a new group of birds




Answer: D

A population of rabbits lives in a meadow with depression that runs through the middle. The depression fills in which water and becomes a river that separates the population into two groups. Over a very long period the two populations develop into entirely different species, no longer capable of reproducing with each other. This is an example of

Naim 03:09 Add Comment

A population of rabbits lives in a meadow with depression that runs through the middle. The depression fills in which water and becomes a river that separates the population into two groups. Over a very long period the two populations develop into entirely different species, no longer capable of reproducing with each other. This is an example of



A. artificial selection

B. mutation

C. sympatric speciation

D. the bottleneck effect

E. allopatric speciation



Answer: E

When a population suddenly reduces in size from habitat loss, natural disaster, or other environmental changes and its subsequent genetic variation is affected, we say it has experienced

Naim 03:09 Add Comment

When a population suddenly reduces in size from habitat loss, natural disaster, or other environmental changes and its subsequent genetic variation is affected, we say it has experienced




A. the founder effect

B. geographic isolation

C. genetic drift

D. the bottleneck effect

E. mutation



Answer: D

Which is the best example of artificial selection?

Naim 03:08 Add Comment

Which is the best example of artificial selection?




A. Bees pollinate different species of flowers.

B. Finches adapt to different sources of food on different islands.

C. An isolated population of frogs develops a phenotype distinct from the original population.

D. Humans breed horses for speed.

E. A small population has an unusually high percentage of a rare phenotype.


Answer: D

Evolution occurs through

Naim 03:07 Add Comment

Evolution occurs through


I. Artificial selection
II. Natural selection
III. Genetic drift


A. I only

B. II only

C. III only

D. II and III

E. I, II and III



Answer: E

Which is the best description of the two communities shown?

Naim 03:05 Add Comment

Which is the best description of the two communities shown?




A. Community 1 has a higher evenness but lower richness than Community 2.

B. Community 1 has a higher evenness and higher richness than Community 2.

C. Community 1 as a higher evenness and equal richness to Community 2.

D. Community 2 has a higher evenness and a higher richness than Community 1.

E. Community 2 has a higher evenness but lower richness than Community 1.


Answer: C

Some scientists estimate that current global extinction rate is about 30,000 species per year. If there are currently 10,000,000 species on Earth, how long will it take to destroy all of the Earth's biodiversity?

Naim 03:04 Add Comment

Some scientists estimate that current global extinction rate is about 30,000 species per year. If there are currently 10,000,000 species on Earth, how long will it take to destroy all of the Earth's biodiversity?



A. less than 100 years

B. between 100 and 300 years

C. between 300 and 500 years

D. between 500 and 700 years

E. between 700 and 1,000 years



Answer: C

Which of the following statements is not correct?

Naim 03:03 Add Comment

Which of the following statements is not correct?



A. Most speciation is thought to occur via allopatric speciation.

B. Polyploidy is an example of sympatric speciation.

C. Speciation can be caused by either natural selection or random processes.

D. Geographic isolation can eventually lead to reproductive isolation.

E. Speciation cannot occur without geographic isolation.




Answer: E

The northern elephant seal (Mirounga angustirostris) was once hunted to near extinction. Only 20 animals remained alive in 1890. After the species was protected from hunting, its population grew to nearly 30,000 animals, but the large population possesses very low genetic variation. Which of the following processes is the best interpretation of this scenario?

Naim 03:03 Add Comment

The northern elephant seal (Mirounga angustirostris) was once hunted to near extinction. Only 20 animals remained alive in 1890. After the species was protected from hunting, its population grew to nearly 30,000 animals, but the large population possesses very low genetic variation. Which of the following processes is the best interpretation of this scenario?



A. evolution by natural selection

B. evolution by artificial selection

C. evolution by the founder effect

D. evolution by the bottleneck effect

E. evolution by genetic drift



Answer: D

In 2002, Peter and B. Rosemary Grant studied a population of Darwin's finches on one of the Gala´pagos Islands that feed on seeds of various sizes. After a drought that caused only large seeds to be available to the birds, they found that natural selection favored those birds that had larger beaks and bodies. Once the rains returned and smaller seeds became much more abundant, however, natural selection favored those birds that had smaller beaks and bodies. Which of the following processes is the best interpretation of this scenario?

Naim 03:02 Add Comment

In 2002, Peter and B. Rosemary Grant studied a population of Darwin's finches on one of the Gala´pagos Islands that feed on seeds of various sizes. After a drought that caused only large seeds to be available to the birds, they found that natural selection favored those birds that had larger beaks and bodies. Once the rains returned and smaller seeds became much more abundant, however, natural selection favored those birds that had smaller beaks and bodies. Which of the following processes is the best interpretation of this scenario?



A. genetic drift

B. founder effect

C. microevolution

D. macroevolution

E. bottleneck effect



Answer: C

The yellow perch is a fish that breeds in spring. A single female can produce up to 40,000 eggs at one time. The species is an example of which of the key ideas of Darwin's theory of evolution by natural selection?

Naim 03:02 Add Comment

The yellow perch is a fish that breeds in spring. A single female can produce up to 40,000 eggs at one time. The species is an example of which of the key ideas of Darwin's theory of evolution by natural selection?



A. Individuals produce an excess of offspring.

B. Humans select for predetermined traits.

C. Individuals vary in their phenotypes.

D. Phenotypic differences in individuals can be inherited.

E. Different phenotypes have different abilities to survive and reproduce.



Answer: A

Which of the following is an example of artificial selection?

Naim 03:02 Add Comment

Which of the following is an example of artificial selection?




A. Cichlids have diversified into nearly 200 species in Lake Tanganyika.

B. Thoroughbred racehorses have been bred for speed.

C. Whales have evolved tails that help propel them through water.

D. Darwin's finches have beaks adapted to eating different foods.

E. Ostriches have lost the ability to fly.


Answer: B

The table below represents the number of individuals of different species that were not counted in three forest communities. Which of the following statements best interprets these data?

Naim 03:01 Add Comment

The table below represents the number of individuals of different species that were not counted in three forest communities. Which of the following statements best interprets these data?



A. Community A has greater species evenness than Community B.

B. Community A has greater species richness than Community B.

C. Community B has greater species evenness than Community C.

D. Community C has greater species richness than Community A.

E. Community A has greater species evenness than Community C.



Answer: D
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