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ECOLOGY
Nitrogen compounds are a part of all organisms. What happens to the nitrogen in an organism after it dies?
A.
B.
C.
D.
It is destroyed by decomposition.
It is recycled and used by other organisms.
It remains trapped in the organism's tissues.
It is all used up by the time the organism dies.
Correct Answer:
B
The global water cycle consists of water circulating among the land, the atmosphere, the oceans, and organisms.
Trees get most of their water directly from
A.
B.
C.
D.
lakes
air
streams
soil
Correct Answer:
D
Deep sea bacteria live at ocean depths too great for light to reach. These bacteria make their own food. Which
of these is the source of energy for the bacteria?
A.
B.
C.
D.
nucleic acids
binary fission
inorganic compounds
DNA replication
Correct Answer:
C
Some types of bacteria live deep in the ocean where sunlight cannot reach. These bacteria use the energy stored
in inorganic molecules to make sugars.
Which of these processes do the bacteria use to produce sugars?
A.
B.
C.
D.
photosynthesis
chemosynthesis
aerobic respiration
nitrogen fixation
Correct Answer:
B
Some bacteria live in habitats without light. They produce their own food using inorganic substances from the
environment.
Which of these terms best describes this process?
A.
B.
C.
D.
photosynthesis
cellular respiration
binary fission
chemosynthesis
Correct Answer:
D
In deep ocean trenches, bacteria produce organic materials from inorganic compounds through the process of
A.
B.
C.
D.
respiration
decomposition
photosynthesis
chemosynthesis
Correct Answer:
D
Use the information below to answer the following.
Aphids are insects that feed on fluids from the stems of plants. After the aphids ingest the plant fluids, they
excrete a liquid called honeydew.
Ladybugs eat aphids, which are a source of protein for the ladybugs. Which of these terms best describes the
relationship between the ladybugs and the aphids?
A.
B.
C.
D.
mutualism
parasite–host
predator–prey
commensalism
Correct Answer:
C
The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the
diagram to answer the following.
Which of these is an abiotic factor that affects the organisms in the estuary ecosystem?
A.
B.
C.
D.
the amount of bacteria in the water
the number of copepods
the amount of salt in the water
the number of scavengers
Correct Answer:
C
Use the information below to answer the following.
Aphids are insects that feed on fluids from the stems of plants. After the aphids ingest the plant fluids, they
excrete a liquid called honeydew.
Some species of ants protect aphids from predators. The ants benefit by feeding on the honeydew produced by
the aphids. Which of these terms best describes the relationship between the aphids and the ants?
A.
B.
C.
D.
mutualism
parasite–host
predator–prey
commensalism
Correct Answer:
A
Cholera bacteria live inside copepods, tiny marine organisms. This type of microscopic bacteria harms the
copepods by feeding off their internal tissues.
Both of these organisms are found in oceans throughout the world. Unfavorable temperatures or salt levels may
cause cholera bacteria to become inactive. When inactive, they do not feed or reproduce. When conditions
become favorable, they become active once again.
A cholera population may depend on the population of copepods in the surrounding water. A simple food chain
showing this relationship is shown below.
Which of these describes the relationship between cholera bacteria and copepods?
A.
B.
C.
D.
mutualism
parasite–host
commensalism
producer–consumer
Correct Answer:
B
Scientists have recently discovered hydrothermal vent communities on the ocean floor. A diagram of a
hydrothermal vent community is shown in the figure below.
The organisms in this community live near heated vents. Inorganic compounds such as sulfides mix with
extremely hot water when they are released from the vents. Bacteria use the sulfides to make food for
themselves and other animals. Many of these bacteria live in the bodies of the giant tubeworms and the giant
white clams that live in this community.
Which of these is an abiotic factor that influences this ecosystem?
A.
B.
C.
D.
food
bacteria
water temperature
giant tubeworms
Correct Answer:
C
Reef-building coral are marine animals with single-celled algae living in their tissues. The coral provide
protection for the algae and the algae provides food for the coral. Which of these statements best explains what
would happen to the coral if the algae die?
A.
B.
C.
D.
The coral would grow well because it does not have a competitor.
The coral would die because it needs the food produced by the algae.
The coral would grow well because it does not have a parasite.
The coral would die because it cannot produce food for the algae.
Correct Answer:
B
A summer camp was built near a lake in the mountains. The campers used the lake for swimming, fishing, and
boating. The relationships between three organisms found in the lake are shown below.
Striped fish are affected by biotic and abiotic factors in their environment. Which of these factors is biotic?
A.
B.
C.
D.
water temperature
mineral nutrients
freshwater algae
inorganic sediments
Correct Answer:
C
Corals are marine animals that often live in tropical seas. Many types of corals have unicellular algae living in
their tissues. The algae provide up to 98 percent of the corals' food. The corals provide protection and inorganic
nutrients for the algae.
Algae leave the coral when the water is too warm. What kind of factor is temperature on this relationship?
A.
B.
C.
D.
biotic
abiotic
parasitic
commensalistic
Correct Answer:
B
The deer tick feeds on the blood of the red squirrel, deer, and deer mouse. Which of these best describes the role
of the deer tick in the forest food web?
A.
B.
C.
D.
parasite
producer
carnivore
omnivore
Correct Answer:
A
When gypsy moth caterpillars hatch, which of these populations benefits first?
A.
B.
C.
D.
red oak
deer tick
blue jay
carpenter ant
Correct Answer:
D
Black skimmers are water birds that live along coastal beaches, bays, estuaries, and marshes. They fly just
above the surface of the water using their lower jaw to catch small fish, shrimp, and other small crustaceans.
These birds nest in simple, unlined depressions in the sand. Scientists have observed a decline in the number of
nests. Some causes of this decline include a lack of suitable nesting sites, beach erosion, and human
disturbances.
When people approach their nests, the birds become aggressive and chase away intruders. Other animals, like
crows, will take advantage of the unprotected nests and feed on the eggs.
Which of these best describes the effects of human disturbance on the black skimmer's eggs?
A.
B.
C.
D.
a biotic factor
an allele
a niche
an abiotic factor
Correct Answer:
A
Which of these terms best describes the relationship between the crows and the black skimmers?
A.
B.
C.
D.
mutualism
commensalism
parasite–host
predator–prey
Correct Answer:
D
Use the relationships in the food web below to answer the following questions.
Which of these lists all of the predators shown in the food web?
A.
B.
C.
D.
cougars only
cougars and snakes
cougars, snakes, and shrews
cougars, snakes, shrews, and mice
Correct Answer:
D
The relationship between the mice and the insects is an example of
A.
B.
C.
D.
commensalism
mutualism
parasite–host
predator–prey
Correct Answer:
D
Use the information below to answer the following question.
A scientist wanted to find out if low numbers of fish found in a nearby lake were related to acid rain. During his
three-year study, he analyzed rainwater and lake water samples. By gathering samples of fish, he estimated the
number of fish in the lake.
Each year he found that both the rainwater and lake water became more acidic, and the number of fish
decreased.
His data suggested that acid rain may be responsible for the decrease in the number of fish found in the lake.
The lake ecosystem includes frogs, freshwater algae, and inorganic sediment. Which of these is an abiotic factor
contained within the lake ecosystem?
A.
B.
C.
D.
frogs
algae
fish
sediment
Correct Answer:
D
Use the information below to answer the following item.
An insecticide is a chemical that kills insects. Most insects are killed the first time they are exposed to an
insecticide. However, some insects carry a gene that enables them to survive their first exposure to an
insecticide. When these surviving insects reproduce, this gene may be inherited by their offspring. The number
of insecticide-resistant insects usually increases over time because increasing numbers of offspring with this
gene are able to survive and reproduce.
What is the ecological relationship between insects and crops?
A.
B.
C.
D.
mutualism
competition
parasitism
commensalism
Correct Answer:
C
Use the information below to answer the following item.
Hummingbirds need large amounts of energy to flap their wings between 60 and 200 times per second. Their
wings beat so rapidly that it is difficult to see them move. They often appear suspended in air for extended
periods of time without changing their location. Hummingbirds have long bills and grooved tongues to reach
into flowers to feed on flower nectar. They also feed on insects.
Which term best describes the ecological relationship between hummingbirds and insects?
A.
B.
C.
D.
mutualism
parasite–host
predator–prey
commensalism
Correct Answer:
C
A protozoan lives inside a rat and takes its nourishment from the rat’s body. Because the protozoan damages the
rat’s brain, the rat loses its fear of cats. A cat attacks an infected rat; the protozoan enters the cat’s body and
completes its life cycle.
Which of these describes the relationship between the protozoan and the rat?
A.
B.
C.
D.
commensalism
parasite–host
mutualism
predator–prey
Correct Answer:
B
Use the information below to answer the following item.
The water quality of the Chesapeake Bay is measured by the Chesapeake Bay Water Quality Monitoring
Program. Scientists measure the salinity, temperature, pH, and oxygen levels to help determine the health of the
Bay. Healthy water also contains appropriate amounts of nutrients. Monitoring water quality helps communities
make decisions about the Bay.
Which of these would likely be the most immediate result if oxygen levels in the Bay decreased by 90%?
A.
B.
C.
D.
decrease in fish populations
decrease in salinity levels
increase in producer populations
increase in water temperature
Correct Answer:
A
Use the information and the figure below to answer the following item.
Many plants that grow in tropical rain forests have specialized roots that anchor them to the branches and trunks
of trees. They do not harm the trees. These plants get food and water from various sources, including the air and
dead organic matter found on the trees.
One example of these plants found in tropical rain forests is the bromeliad. Its leaves form a cup-like structure
that is able to hold water. This water provides a feeding and breeding area for many insects and frogs. Snakes
and lizards also come to these plants in search of food and water. A cross-section showing the inside of a
bromeliad is shown below.
Snakes and lizards come to the bromeliads to feed on frogs and their eggs. The relationship between the snakes,
lizards, and frogs can best be described as
A.
B.
C.
D.
mutualism
parasite–host
predator–prey
commensalism
Correct Answer:
C
Use the information and the drawing below to answer the following item.
The desert climate is caused by geographic conditions such as location, high atmospheric pressure, and
proximity of mountain ranges. Average desert rainfall amounts are usually less than 50 cm per year. Soil in
deserts is coarse, sandy, and rocky. Desert plants and animals have specialized characteristics that help them
survive in the harsh environment. An example is the Saguaro cactus. The Saguaro has a shallow root system
with a main taproot and other roots that radiate out and collect surface water. The trunk of the Saguaro has the
ability to expand while storing water. The sweet-nectar flowers of the Saguaro attract white-winged doves, bats,
and other animals. These animals feed on the nectar. They are necessary for cross-pollination. Cross-pollination
occurs when the pollen of a flower is carried to a flower on another plant. The illustration below shows the
Saguaro cactus.
Which of these best describes the ecological relationship between white-winged doves and the Saguaro cactus?
A.
B.
C.
D.
mutualism
competition
parasite–host
predator–prey
Correct Answer:
A
Use the information below to answer the following item.
Many bird species in the forests of eastern North America have very large geographic ranges. Bird species in
tropical forests have very small geographic ranges. Many forest areas within the ranges of these birds are being
destroyed. Scientists believe that the destruction of forests affects birds with small ranges more than birds with
large ranges.
Which of these is an abiotic factor in both North American and tropical forest ecosystems?
A.
B.
C.
D.
age of trees
intensity of light
number of consumers
number of producers
Correct Answer:
B
A new species is introduced into an area. This can have harmful effects on species already inhabiting the area.
The harmful effects are most likely a result of
A.
B.
C.
D.
succession
mutualism
competition
commensalism
Correct Answer:
C
Use the information below to answer the following item.
Scientists have observed that when a largemouth bass tries to eat a whirligig beetle, the fish is likely to get more
than just a meal. Once inside the mouth of a bass, the beetle releases a foul-tasting substance into the fish’s
mouth. The fish responds to this by swishing the beetle around in its mouth, spitting the beetle out into the
water, and scooping the beetle back into its mouth. The bass is exhibiting a “flushing” behavior. Unlike other
insects, whirligig beetles do not release all of their foul-tasting substance the first time they are pulled into a
predator’s mouth. Each time the bass scoops the beetle back into its mouth, more of the substance is released.
The bass must exhibit “flushing” again and again. If the bass tires of “flushing” before the beetle runs out of its
foul-tasting substance, the beetle can avoid becoming the bass’s next meal.
The ecological relationship between largemouth bass and whirligig beetles is best described as
A.
B.
C.
D.
predator–prey
parasite–host
mutualism
commensalism
Correct Answer:
A
Use the information below to answer the following item.
Scientists determined that excess fertilizer from farms entered a shallow lake. The fertilizer caused an increase
in aquatic plants in the lake and then a decrease in oxygen in the water. Next, organic debris collected on the
bottom of the lake. Over several years, the lake gradually filled in with organic sediment.
As the fertilizer levels increased, the population of consumers in the lake declined. Which change most likely
caused this decline?
A.
B.
C.
D.
increase in light intensity
decrease in available oxygen
increase in temperature
decrease in carbon dioxide
Correct Answer:
B
Use the information and the drawing below to answer the following item.
The pitcher plant is a carnivorous plant that consumes various small organisms such as spiders and frogs. The
pitcher plant is often found in areas with soil that is very acidic and contains few nutrients. The pitcher plant
consumes organisms that help supply the plant with nutrients that are not in the soil. A diagram of the pitcher
plant is shown below.
Which of these best describes the relationship between the pitcher plant and the insects?
A.
B.
C.
D.
symbiotic
competitive
parasite–host
predator–prey
Correct Answer D
The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the
diagram to answer the following.
Which of these best describes the role of the blue crab in the estuary ecosystem?
A.
B.
C.
D.
carnivore
herbivore
producer
omnivore
Correct Answer:
D
The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the
diagram to answer the following.
The croaker, menhaden, and striped bass are fished for food. Which of these graphs shows how a decrease in
the fish populations would most likely affect the copepod population?
A.
C.
B.
D.
Correct Answer:
A
Use the diagram of the marine food web below to answer the following.
Which of these best describes the role of the krill in this food web?
A.
B.
C.
D.
decomposer
consumer
producer
parasite
Correct Answer:
B
A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea
ecosystem.
The deep-sea ecosystem is a stable ecosystem. Which of these is a characteristic of most stable ecosystems?
A.
B.
C.
D.
They contain a wide variety of organisms.
They contain very few organisms.
Organic nutrients are in short supply.
Sunlight is not used to make food.
Correct Answer:
A
Use the technical passage below to answer the following.
SCIENTISTSEXPLOREANASPECTOFFISHMIGRATION
Toxic pollutants from agriculture and industry have been found worldwide, even in areas that are far from
pollution sources. Until now, scientists have blamed air currents for spreading toxins far from their sources.
However, a recent study indicates that fish can transport toxins over long distances.
Scientists developed this hypothesis when toxins were mysteriously found in a remote lake in Sweden. A team
of scientists from Lund University hypothesized that salmon accumulated and stored toxins in their fatty tissues
when they were in the Baltic Sea. The salmon migrated upstream, spawned, and then died in the lake, releasing
toxins as their bodies decomposed.
To test this hypothesis, the scientists traveled to Alaska, where they carried out an experiment in two
neighboring lakes, Lower Fish Lake and Round Tangle Lake. Lower Fish Lake is open to migrating salmon,
while Round Tangle Lake is closed to migrating salmon because of numerous waterfalls and rapids. A small
fish, the arctic grayling, lives in both lakes. Fish eggs are a large part of its diet. When the scientists examined
the arctic grayling from both lakes, the arctic grayling in Lower Fish Lake had more than twice the
concentration of toxins in their bodies as the arctic grayling in Round Tangle Lake. Since both lakes are
exposed to similar levels of air pollution, the difference in toxin levels found in the arctic grayling must be due
to other factors.
In a related experiment, scientists caught salmon throughout their migration and tested their fatty tissues for
toxins. Even though the fatty tissue deposits were gradually used up, toxin levels remained about the same
throughout the 400-kilometer journey up the Copper River from the Gulf of Alaska to Lower Fish Lake. Instead
of metabolizing the toxins, the salmon stored them in other body tissues that also contain fat, and in their eggs.
Both of these studies support the hypothesis that migrating salmon can transport pollutants to new areas.
In addition to eating fish eggs, the arctic grayling also eats insects and small fish. What is the ecological role of
the arctic grayling?
A.
B.
C.
D.
herbivore
decomposer
omnivore
carnivore
Correct Answer:
D
Use the information and the food web below to answer the following.
A marine environment provides a habitat for a variety of plants and animals. A small part of a marine food web
is shown below.
Which of these describes the role of the sanderling in the marine food web?
A.
B.
C.
D.
producer
herbivore
carnivore
omnivore
Correct Answer:
C
The energy pyramid below shows the flow of energy through the organisms in a kelp forest ecosystem in the
Pacific Ocean. Use the energy pyramid to answer the following.
What is the lowest level of the energy pyramid that contains carnivores?
A.
B.
C.
D.
Level 1
Level 2
Level 3
Level 4
Correct Answer:
C
A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea
ecosystem.
The scientists discovered a species of fish that eats other fish and decaying matter. Which of these does not
describe the newly discovered fish?
A.
B.
C.
D.
consumer
predator
scavenger
producer
Correct Answer:
D
Part of the food web in Yellowstone National Park is shown below.
Gray wolves were reintroduced into Yellowstone National Park in 1995. Two years later, the population of
coyotes had decreased by 50%. Coyotes were found in all habitats of the park before the gray wolves were
reintroduced. Now, coyotes are most often found in the hills and mountains.
Which of these describes the role of the vole in the Yellowstone ecosystem?
A.
B.
C.
D.
decomposer
producer
herbivore
carnivore
Correct Answer:
C
Use the diagram of the marine food web below to answer the following.
Which of these best describes the relationship between the phytoplankton and zooplankton?
A.
B.
C.
D.
producer–consumer
mutualism
parasite–host
commensalism
Correct Answer:
A
How would the food web be affected if the phytoplankton were removed?
A.
B.
C.
D.
Only organisms that feed directly on the phytoplankton would be affected.
Only organisms that feed directly on the zooplankton would be affected.
Only the killer whale and the seals would be affected.
All the organisms would be affected.
Correct Answer:
D
An ecosystem contains organisms interacting with each other and their physical environment. Which of these is
the best indicator of a healthy ecosystem?
A.
B.
C.
D.
There are few decomposers.
There are many different species.
There are few herbivores.
There is a large population of only one species.
Correct Answer:
B
Which of these describes the role of the red oak in the forest food web?
A.
B.
C.
D.
omnivore
parasite
herbivore
producer
Correct Answer:
D
Use the relationships in the food web below to answer the following question.
According to the food web, which of these supply energy for all the other organisms?
A.
B.
C.
D.
snakes
insects
grasses
cougars
Correct Answer:
C
Use the technical passage to answer the following item.
BlackBearSightingsareontheRise
Black bears are the largest mammals native to Maryland. Adults typically weigh between 150 and 400 pounds.
Their color can range from black to brown to cinnamon. They have a tan muzzle and may have some white on
their chest. Black bears have a short, bobbed tail and small, rounded ears. They live mostly in thick forested
areas in Maryland. Black bears are shy, solitary animals. They require a lot of space for their home range. Adult
black bears can have a home range of about 15 to 25 square miles.
When the land was being settled, the black bear’s habitat was cleared for farms and villages. Because settlers
misunderstood bears and felt threatened by them, bears were killed in large numbers. As a result, black bears
were soon found only in small numbers and only in the westernmost part of the state. In 1956 there were only
about 12 black bears in the whole state. When the black bear population was studied in 2000, as many as 437
bears were estimated to live in Maryland.
Black bears eat a lot of different foods. They will eat whatever is easy to get. Their favorite natural foods
include plants, berries, fruits, acorns, insects, roots, and grasses. They may also eat reptiles, amphibians, fish,
and dead animals. If available, black bears will eat non-natural foods associated with humans, such as garbage,
bird seed, pet food, and agricultural crops like corn. Black bears will only come near a home if there is
something to attract them, such as food. Once a bear finds available food, it will likely return again and again.
Both black bears and humans feel threatened when confronted with one another. When threatened, bears often
display unusual behaviors, such as hitting the ground with its paws, charging only to stop several feet from the
threat, or standing upright on its hind legs. Since humans usually perceive these behaviors as being aggressive,
black bears are once again being viewed as a problem.
What is the ecological role of the black bear?
A.
B.
C.
D.
producer
carnivore
omnivore
decomposer
Correct Answer:
C
Use the information and the figure below to answer the following item.
Many plants that grow in tropical rain forests have specialized roots that anchor them to the branches and trunks
of trees. They do not harm the trees. These plants get food and water from various sources, including the air and
dead organic matter found on the trees.
One example of these plants found in tropical rain forests is the bromeliad. Its leaves form a cup-like structure
that is able to hold water. This water provides a feeding and breeding area for many insects and frogs. Snakes
and lizards also come to these plants in search of food and water. A cross-section showing the inside of a
bromeliad is shown below.
Which of these types of organisms break down dead organic matter in the rain forest?
A.
B.
C.
D.
producers
predators
herbivores
decomposers
Correct Answer:
D
Use the information below to answer the following item.
Scientists genetically modified a variety of corn to protect it against pests like the corn borer. The corn borer is
an insect caterpillar that feeds on the corn stalk, which weakens the stalk and makes it fall over. A new gene in
the genetically modified corn causes the plant to produce a chemical that is toxic to the corn borer. Some people
are concerned that the genetically modified corn could harm other insects such as the monarch butterfly
caterpillar. The monarch caterpillar eats leaves of milkweed plants that might be coated with toxic corn pollen.
However, not all researchers agree with the concerns regarding the monarch butterfly caterpillar. They state that
it is unusual for large amounts of harmful corn pollen to be found on milkweed leaves. Also, only a small
percentage of caterpillars feed on the milkweed plants near corn fields.
Which of these describes the trophic level of the corn borer?
A.
B.
C.
D.
carnivore
herbivore
producer
decomposer
Correct Answer:
B
Use the information below to answer the following item.
Many bird species in the forests of eastern North America have very large geographic ranges. Bird species in
tropical forests have very small geographic ranges. Many forest areas within the ranges of these birds are being
destroyed. Scientists believe that the destruction of forests affects birds with small ranges more than birds with
large ranges.
As a result of the destruction of forests, birds with a small geographic range are most likely to
A.
B.
C.
D.
lose their specific niche
adapt to a new environment
lose their ability to navigate
become less susceptible to disease
Correct Answer:
A
Use the information below to answer the following item.
In an ocean environment, marine life is most abundant in the euphotic zone. This zone extends from the surface
waters to a depth of 200 meters, the deepest depth that sunlight can reach. It is in this range that phytoplankton
capture energy from the sun. Although they are microscopic organisms, phytoplankton are the foundation that
supports the marine food web.
Which trophic level is most likely missing from an ocean floor food web at a depth of 800 meters?
A.
B.
C.
D.
carnivores
decomposers
producers
scavengers
Correct Answer:
C
Use the diagram of the marine food web below to answer the following.
Cod is a popular fish in the human diet. If too many cod were removed due to overfishing, which of these would
most likely occur?
A.
B.
C.
D.
The penguins would become extinct.
The phytoplankton population would decrease.
The leopard seals would eat more squid.
The killer whale population would increase.
Correct Answer:
C
Use the information and the food web below to answer the following.
A marine environment provides a habitat for a variety of plants and animals. A small part of a marine food web
is shown below.
Horseshoe crabs are used by fisherman for bait. If the horseshoe crab population were reduced by overfishing,
which of these groups of organisms would most likely decrease in number?
A.
B.
C.
D.
plankton, razor clams, and loggerhead turtles
sanderlings, loggerhead turtles, and striped bass
grackles, plankton, and diamondback terrapin
striped bass, sanderlings, and razor clams
Correct Answer:
B
The pesticide DDT was used to kill mosquitoes for many years. DDT entered bodies of water, moved up the
food chain, and built up in the tissues of fish. When female bald eagles ate these fish, they produced eggs with
very thin shells. The eggs broke when the eagles sat on their nests. The U.S. government banned the use of
DDT in 1972.
Which of these graphs most likely shows how the ban of DDT affected the bald eagle population?
A.
B.
C.
D.
Correct Answer:
B
The energy pyramid below shows the flow of energy through the organisms in a kelp forest ecosystem in the
Pacific Ocean. Use the energy pyramid to answer the following.
How would the populations of other organisms in the energy pyramid be affected if the population of sea
urchins suddenly decreased?
A.
B.
C.
D.
Both the kelp and the sheephead populations would increase.
Both the kelp and the sheephead populations would decrease.
The kelp population would decrease, and the sheephead population would increase.
The kelp population would increase, and the sheephead population would decrease.
Correct Answer:
D
Rain forests are often cleared to provide land for farming. Which of these outcomes is the most immediate
effect of this practice on the global environment?
A.
B.
C.
D.
an increase in acid rain
depletion of the ozone layer
the decreased production of food
an increase in atmospheric carbon dioxide levels
Correct Answer:
D
Black skimmers are water birds that live along coastal beaches, bays, estuaries, and marshes. They fly just
above the surface of the water using their lower jaw to catch small fish, shrimp, and other small crustaceans.
These birds nest in simple, unlined depressions in the sand. Scientists have observed a decline in the number of
nests. Some causes of this decline include a lack of suitable nesting sites, beach erosion, and human
disturbances.
When people approach their nests, the birds become aggressive and chase away intruders. Other animals, like
crows, will take advantage of the unprotected nests and feed on the eggs.
A continued decrease in black skimmer populations will most likely lead to
A.
B.
C.
D.
a decrease in scavenger populations
an increase in producer populations
a decrease in decomposer populations
an increase in prey animal populations
Correct Answer:
D
The populations of wolves and other large predators have decreased throughout the United States. This
disruption of the natural food web will most likely lead to
A.
B.
C.
D.
a decrease in prey animals
an increase in producers
the overpopulation of prey animals
the overpopulation of scavengers
Correct Answer:
C
The use of certain chemicals by humans has caused holes to form in the Earth’s ozone layer. This allows more
ultraviolet (UV) light to reach the oceans. Scientists are concerned that an increase in UV light will start killing
microscopic marine algae.
Which of these statements describes how the ocean food web would be affected by a large decrease in
microscopic marine algae?
A.
B.
C.
D.
There will be fewer marine animals because there will be fewer producers.
There will be no change because the algae are very small.
There will be more consumers because the UV light kills producers.
There will be fewer consumers because the UV light kills decomposers.
Correct Answer:
A
BlackBearSightingsareontheRise
Black bears are the largest mammals native to Maryland. Adults typically weigh between 150 and 400 pounds.
Their color can range from black to brown to cinnamon. They have a tan muzzle and may have some white on
their chest. Black bears have a short, bobbed tail and small, rounded ears. They live mostly in thick forested
areas in Maryland. Black bears are shy, solitary animals. They require a lot of space for their home range. Adult
black bears can have a home range of about 15 to 25 square miles.
When the land was being settled, the black bear’s habitat was cleared for farms and villages. Because settlers
misunderstood bears and felt threatened by them, bears were killed in large numbers. As a result, black bears
were soon found only in small numbers and only in the westernmost part of the state. In 1956 there were only
about 12 black bears in the whole state. When the black bear population was studied in 2000, as many as 437
bears were estimated to live in Maryland.
Black bears eat a lot of different foods. They will eat whatever is easy to get. Their favorite natural foods
include plants, berries, fruits, acorns, insects, roots, and grasses. They may also eat reptiles, amphibians, fish,
and dead animals. If available, black bears will eat non-natural foods associated with humans, such as garbage,
bird seed, pet food, and agricultural crops like corn. Black bears will only come near a home if there is
something to attract them, such as food. Once a bear finds available food, it will likely return again and again.
Both black bears and humans feel threatened when confronted with one another. When threatened, bears often
display unusual behaviors, such as hitting the ground with its paws, charging only to stop several feet from the
threat, or standing upright on its hind legs. Since humans usually perceive these behaviors as being aggressive,
black bears are once again being viewed as a problem.
Use the technical passage to answer the following item.
Recent increases in bear-human interactions in the westernmost part of Maryland are causing serious problems.
Which of these is the most likely cause for this increased interaction?
A.
B.
C.
D.
increase in non-natural food sources
decrease in the black bear population
larger forested areas
changes in climate
Correct Answer:
A
Which of these shows how energy is usually transferred in a food chain?
A.
B.
C.
D.
herbivore
producer
carnivore
producer
Correct Answer:
D
producer
carnivore
herbivore
herbivore
carnivore
herbivore
producer
carnivore
The diagram below represents a Coastal Food Web.
Global warming causes an increase in coastal water temperatures. Increased coastal water temperature causes a
decrease in reproduction of krill. Which of these would most likely experience an increase in population?
A.
B.
C.
D.
gull
herring
anchovy
phytoplankton
Correct Answer:
D