WorksheetsUnit 2 Benchmark Test
Total questions: 43
Worksheet time: 32mins
Ocean waters have a varying carrying capacity for phytoplankton and other organisms that perform photosynthesis. The carrying capacity is very high near the surface, and then decreases with depth. It is zero in the deepest ocean waters. Which statement about the water is MOST useful for explaining this variation?
Temperature decreases with depth.
Brightness decreases with depth.
Salinity increases with depth.
Dissolved carbon dioxide decreases with depth.
Dissolved carbon dioxide increases with depth.
Waters in the coastal ocean tend to be more productive than waters of similar depth in the open ocean. What is the main reason for the productivity difference?
more sunlight
warmer temperatures
nutrient-rich runoff from the land
higher levels of dissolved carbon dioxide
higher levels of dissolved oxygen
Human activities that disrupt the carbon cycle include the burning of fossil fuels. Which statement best summarizes this disruption?
Burning fossil fuels increases the energy stored in carbon compounds.
Burning fossil fuels adds carbon compounds to all Earth systems.
Burning fossil fuels transforms carbon from compounds to its element form.
Burning fossil fuels causes other processes of the carbon cycle to occur at a faster rate.
Burning fossil fuels shifts carbon compounds from the geosphere to the atmosphere.
Isabella argues that ecosystems generally maintain consistent numbers and types of organisms, but that they can be severely disrupted by a mass extinction. Which is the MOST likely cause of a mass extinction?
an outbreak of a disease
the spread of invasive species
global climate change that occurs rapidly
global climate change that occurs gradually
an isolated natural disaster, such as an earthquake or volcanic eruption
Scientists cite evidence that human activities have been causing global climate change, which is affecting ecosystems worldwide. Which of these actions would likely be the MOST effective in slowing global climate change and its harmful effects?
Reduce the use of artificial fertilizers to grow crops
Add devices to coal-burning power plants to capture sulfur and nitrogen compounds.
Ban the use of chlorofluorocarbons (CFCs), which damage the ozone layer.
Replace fossil fuel consumption with renewable energy resources that do not transfer carbon to the atmosphere.
Reduce tourism and fishing in polar regions, which would reduce the rate that ice melts.
In an experiment, a scientist encloses a mouse in a sealed terrarium. The terrarium contains sufficient water for the mouse to drink and dried seeds for food. After several hours, the mouse dies. Which statement provides the MOST likely explanation for the death of the mouse?
The mouse was poisoned by high carbon dioxide levels or suffocated from low oxygen levels, both problems caused by the lack of photosynthesis in the terrarium.
The mouse exhausted the supply of carbon dioxide in the air, a problem caused by the lack of photosynthesis in the terrarium.
The mouse poisoned by the high nitrogen content of the water, which in nature is reduced by the growth of algae.
The mouse was poisoned by the high nitrogen content of the air, which in nature is reduced by nitrogen fixation.
The mouse was poisoned by the high oxygen content of the air, which in nature is reduced by photosynthesis.
All living things depend on the movement of water between ecosystems and their environment, which is part of the water cycle. Bruce claims that the water cycle could continue without an energy source. Which statement provides the strongest evidence for an argument AGAINST Bruce’s claim?
Sunlight provides the energy needed for condensation and precipitation.
Sunlight provides the energy needed for evaporation and transpiration.
Plants and animals use energy to obtain and transport water.
Plants use the energy of sunlight to perform photosynthesis.
Oxygen and hydrogen gases combine to produce water, and the reaction releases energy.
Plants that thrive in estuaries include mangroves and many grasses. However, the biodiversity of estuaries is limited because many plants cannot growth there, despite the warm temperatures and abundant water. Compared to plants that grow on dry land, or in rivers and lakes, plants that grow in estuaries have a higher tolerance for which of these conditions?
rocky soil
cold water
direct sunlight
nutrient-poor soil
salty water
Atmospheric carbon dioxide levels have been increasing from year to year. However, in locations in the northern hemisphere, carbon dioxide levels may decrease slightly during the summer months. Which is the MOST likely explanation for these slight summertime decreases?
an increase in the rate of cellular respiration during the summer
a decrease in the rate of cellular respiration during the summer
an increase in the rate of photosynthesis during the summer
an increase in the rate of nitrogen fixation during the summer
an increase in the frequency of thunderstorms and hurricanes during the summer
Carla is studying the relationships among the organisms in a local nature preserve. Carla has made a drawing showing how the organisms in the nature preserve interact. To represent land plants, she has drawn a tuft of grass in her diagram. To represent water plants, she has drawn a type of algae. The organisms are not drawn to scale.
Carla’s food web provides evidence for which of these relationships in the ecosystem?
Because small fish consume shrimp, the small fish would die without a healthy shrimp population.
Because bobcats consume animals only, they do not depend on the plants and algae of the ecosystem.
Because bobcats consume raccoons, bobcats act as a limiting factor on the raccoon population.
Because catfish consume shrimp, catfish act as a limiting factor on the shrimp population.
Because bobcats are the top predator of the ecosystem, none of the other organisms act as a limiting factor of the bobcat population.
Carla is studying the relationships among the organisms in a local nature preserve. Carla has made a drawing showing how the organisms in the nature preserve interact. To represent land plants, she has drawn a tuft of grass in her diagram. To represent water plants, she has drawn a type of algae. The organisms are not drawn to scale.
Like many food webs, Carla’s food web does not show decomposers. How would the ecosystem be altered without the actions of decomposers?
Dead matter would build up, and all populations would eventually decrease
Dead matter would build up, but only the populations of grasses and other small plants would decrease.
The plants or animals would begin to recycle the dead matter, and the ecosystem would function normally.
The plants or animals would begin to recycle the dead matter, altering most or all of the feeding relationships.
Dead matter would build up, causing animal populations to decrease but plant populations to increase.
Carla is studying the relationships among the organisms in a local nature preserve. Carla has made a drawing showing how the organisms in the nature preserve interact. To represent land plants, she has drawn a tuft of grass in her diagram. To represent water plants, she has drawn a type of algae. The organisms are not drawn to scale.
Recently, a plant disease was accidentally introduced into the area via a shipment of garden flowers from Southeast Asia. This disease is killing many different kinds of land plants. Based on Carla’s diagram, what can you predict will happen to the ecosystem in the nature preserve as a result of the plant disease?
The population of catfish will increase, because the population of small fish and algae will decrease.
The population of catfish will decrease, because the population of shrimp will decrease.
Raccoons will switch to eating fish when the plant foods they prefer become scarce.
The alligator population will be unaffected, because alligators do not eat plants.
The muskrat population will decrease, which in turn will cause the raccoon and bobcat populations to decrease.
Water cycles among the biosphere, hydrosphere, atmosphere, and geosphere. The illustration shows the main processes involved in the water cycle.
Which of the following describes a process of the biosphere that is part of the water cycle?
Surface water seeps into the air in the process of transpiration.
Groundwater is restored by the leaves of plants during photosynthesis.
Water is generated from hydrogen and oxygen during photosynthesis.
Water evaporates from leaves into the atmosphere in the process of transpiration.
Plants absorb water from the atmosphere in the process of transpiration.
How does the phosphorus cycle differ from the biogeochemical cycles of other elements, including the carbon, oxygen, and nitrogen?
Phosphorus cycles through the biosphere, geosphere, and hydrosphere, but not the atmosphere.
Phosphorus forms chemical compounds with many other elements.
Phosphorus cycles through nonliving systems, but not the biosphere.
Phosphorus is most common as a gas in the atmosphere.
Phosphorus cycles through the geosphere, hydrosphere, and atmosphere, but not the biosphere.
In any ecosystem, how does total biomass compare between the producers and primary consumers?
The producers and primary consumers have equal biomass, due to the conservation of energy.
The producers have significantly more biomass, due to much of their energy being lost as heat when they are consumed.
The producers have significantly less biomass, due to the huge volume of food eaten by many consumers.
The producers have significantly less biomass, due to the relative inefficiency of photosynthesis in converting light energy to chemical energy.
The producers have significantly more biomass due to the high efficiency of photosynthesis in converting light energy to chemical energy.
Which geometric model is generally used to represent the trophic levels of an ecosystem?
a circle, because both matter and energy cycle through feeding relationships
a circle, because the populations in each trophic level depends directly on the other populations for matter and energy.
a square, because there generally are four trophic levels of equal population size.
a pyramid or triangle, because available energy increases from one trophic level to the next
a pyramid or triangle, because available energy decreases from one trophic level to the next
Rabbits eat grasses and other plants. Suppose that a population of rabbits in a meadow increases over a period of time. Of the following events, which is MOST likely to be the cause of this increase?
decreased biomass of meadow grasses
increased population of plant-eating insects
emigration of rabbit predators from the meadow
immigration of rabbit competitors from the surrounding area
an equal decrease in both birthrate and death rate of the rabbits
The graph represents the growth of a population of dandelions over time.
The population is MOST LIKELY growing under which set of conditions?
high competition for limited resources
unlimited resources and no competition
the introduction of a bacteria-killing drug
the introduction of a food source that bacteria cannot use
a gradual increase in temperature, from 0°C to 100°C
A population is increasing in a pattern of logistic growth. What happens when the population reaches carrying capacity?
The growth rate decreases because births increase.
The growth rate increases because deaths increase.
The size of the population continues to grow exponentially.
The size of the population remains at or near its maximum.
The population decreases sharply, perhaps to zero.
Which feature of the graph indicates Country 2 has slow population growth?
the symmetry across the vertical line
the total percent of the population younger than 75
the variations in the sizes of the bars for ages 75 and older
the variations in the sizes of the bars for ages 75 and younger
the similarity in the sizes of the bars for ages 59 and younger
The graph shows the rabbit population in South Australia over time. It also shows the measures that were used to control the size of the population.
Myxomatosis is a disease of rabbits that is caused by a virus. Which of the following BEST describes myxomatosis and its effect on the rabbit population?
Myxomatosis is a density-independent limiting factor that had a drastic but temporary effect on the rabbit population.
Myxomatosis is a density-independent limiting factor that drastically and permanently reduced the rabbit population.
Myxomatosis is a density-dependent limiting factor that had a temporary, minimal effect on the rabbit population.
Myxomatosis is a density-dependent limiting factor that drastically and permanently reduced the rabbit population.
Myxomatosis is either a density-dependent or density-independent limiting factor, depending on the size of the rabbit population when it strikes.
The graph shows the birthrate and death rate in China from 1950–2010.
Which of the following best describes the changes to China’s population for the years 1975 to 2010? Assume that immigration and emigration had a minimal effect on China’s population.
The population was decreasing due to a decreasing birthrate.
The population was decreasing due to a change in government policy.
The population remained the same due to a mostly constant death rate.
The population was increasing due to a greater birthrate than death rate.
The population was decreasing to a relatively constant, high death rate.
As shown by the graph, both the birthrate and death rate changed significantly around 1960. Which of these events was MOST likely the main cause of these changes?
a change in government policy that allowed emigration from the country
a change in government policy that increased the food supply
a severe drought that greatly reduced the food supply
enacting of the one-child policy
repeal of the one-child policy
Which of the following is an example of how a density-independent limiting factor could affect a population?
A population of algae stops increasing when it covers the surface of a pond.
A hurricane blows down most of the palm trees on an island.
Invasive weeds spread rapidly across a meadow.
Wolves prey on a population of deer in a forest.
Deer begin suffering from parasites when they live too closely together.
Which of these events that involve carrying capacity will cause a species to become extinct?
Limiting factors change significantly enough to reduce carrying capacity to near zero.
Limiting factors change significantly enough to drastically increase the carrying capacity.
Populations of the species increase beyond the carrying capacity of their environments.
All of the populations in an ecosystem reach carrying capacities at the same time.
Limiting factors change significantly, but the carrying capacity remains about the same.
The last ice age ended about 10,000 years ago, and the glaciers retreated, leaving behind bare gravel, rocks, and sand. Huge chunks of ice were also left where the glaciers had been for many thousands of years. These chunks of ice melted, creating small lakes and ponds.
What are the first organisms that were MOST LIKELY to have begun growing on the bare rock?
pioneer species such as lichen
pioneer species such as fungi and insects
tall trees such as aspen and pine
small shrubs such as dwarf willow
wildflowers such as fireweed
The last ice age ended about 10,000 years ago, and the glaciers retreated, leaving behind bare gravel, rocks, and sand. Huge chunks of ice were also left where the glaciers had been for many thousands of years. These chunks of ice melted, creating small lakes and ponds.
Which statement BEST describes one of the changes that the area experienced after the ice age ended?
Glaciers expanded gradually, covering and crushing the forest.
As sediments and dead vegetation slowly filled the pond, the types of plants in the community changed.
Although terrestrial communities changed due to succession, aquatic communities remained stable over time.
Although aquatic communities changed due to succession, terrestrial communities remained stable over time.
Submerged water plants slowly replaced plants such as water irises, cattails, and arrowhead, which grow in shallow water or mud.
Each year after harvest, a farm is cleared to prepare for the next year’s crop. One year, the farm is abandoned, and new crops are not planted. The illustration shows what happened to the farm after it was abandoned.
Which of the following statements BEST describes the succession that occurred on the farmland?
Secondary succession began when lichens grew on bare rock.
Secondary succession occurred because the land contained soil suitable for plant growth.
Primary succession occurred because there were no plants growing in the abandoned farmland.
Primary succession occurred that resulted in shrubs, and then secondary succession occurred that resulted in tall trees.
Primary succession occurred when the pioneer species arrived, and then secondary succession immediately followed.
Each year after harvest, a farm is cleared to prepare for the next year’s crop. One year, the farm is abandoned, and new crops are not planted. The illustration shows what happened to the farm after it was abandoned.
Suppose the climate was cooler and wetter when the farm was built than it was when abandoned. Which is the MOST LIKELY way this would affect succession on the abandoned field?
Instead of a temperate forest, the climax community would be a grassland or shrubland better suited for hotter, drier conditions.
The pine forest community would appear after the oak forest community, because the warm conditions would make the oak trees grow faster.
The climate change would not affect succession, because the growing trees would shade and protect the ground, making conditions cooler and wetter.
Succession would occur in reverse order, because the trees would die off in hotter, drier conditions, and only the short plants would remain.
Succession would not occur, because succession requires a stable climate for one community to replace another.
After a forest fire, the forest gradually returns through the process of ecological succession. Which of these events is MOST likely to occur during this process?
The first plants to begin growing in the burnt soil are the most likely to become the adult trees of the climax community.
As young plants grow taller, they shade the shorter plants beneath them, causing the shorter plants to die off.
The community of plants changes over time, while the community of animals remains about the same.
As succession occurs, the community gradually becomes less diverse and less complex.
Lichens and other pioneer species are the only community members for many years, as only they can grow on bare rock.
A variety of potato species grows in the wild in South America. Scientists are concerned that these species could go extinct if they are not protected. How would preserving these species MOST LIKELY be useful to human activities?
The wild potatoes could replace the potatoes raised for food today.
The wild potatoes could be raised for food in certain climates or soils where potatoes are not grown today.
The wild potatoes could be raised for purposes apart from food, such as for drugs or medicines.
The genes of the wild potatoes could be used to improve a variety of crops, but not other potatoes.
The genes of the wild potatoes could be used to improve the potatoes raised for food.
Resilience is defined as a system’s ability to recover after a disturbance. Which example describes a consequence to the resilience of a population if some of the population’s biodiversity is lost?
When a wildfire strikes, most of the members of a plant population are burned and killed.
When the climate becomes warmer, almost all members of an animal population die off.
When the soil becomes saltier, the community is gradually replaced with organisms that can tolerate a saltier environment.
When a new predator arrives, a prey population is forced to develop behaviors to protect themselves.
When a new prey animal arrives, most members of a predator population begin hunting the prey.
A scientist is arguing that preserving biodiversity is a major global challenge, and that the solution to the challenge would support the needs and wants of society. To support this argument, the scientist cites a flowering plant called the Madagascar periwinkle. Which of the following statements about the plant would be MOST useful for the scientist to include?
Flowers of the Madagascar periwinkle can be pollinated by long-tongued insects.
The Madagascar periwinkle is a source of two chemicals used to fight several different types of cancer.
The Madagascar periwinkle can withstand a variety of climates and disturbances, which helps it thrive in many environments.
The Madagascar periwinkle is a popular garden plant around the world, and has been cultivated to produce flowers in shades of white, pink, and purple.
The Madagascar periwinkle, like other plants, takes up carbon dioxide and releases oxygen.
Human activities around the world can and do alter ecosystems and the services they provide. Which of these human-caused changes to ecosystems is MOST LIKELY to preserve or increase ecosystem services?
clearing a tropical rain forest for new farms or ranches
raising high-yield wheat in a field, in which all plants are genetically identical
diverting the water from wetlands into irrigation ditches
using fertilizer to raise a crop of soybeans on a large field
allowing a farm field to remain fallow, or unplanted, for several seasons
Border officials may inspect the baggage of anyone who enters the United States from another country. The officials are trained to identify and confiscate certain plants and animals that are banned from the country. Which is the MOST LIKELY way that the bans help protect biodiversity in ecosystems of the United States?
The bans protect the genes of food crops, because the foreign organisms may use a different genetic code.
The bans protect native animals from new food sources, which may prove more nutritious than their current foods.
The bans protect native plants and animals from genetic pollution, because genes can transfer between species.
The bans protect ecosystems from invasive species and new pests, which could replace or harm native plants and animals.
The bans protect the rights of farmers and ranchers, because individuals could raise foreign plants in gardens or in their homes.
Scientists cite evidence that the global climate is changing. Which of the following is an impact, or likely potential impact, of climate change on human activities?
I. increased flooding in coastal regions due to a rise in sea level
II. changing water supplies to farms and ranches due to a change in precipitation patterns
III. increased damage from stronger hurricanes due to warmer ocean temperatures
I. only
I. and II.
III. only
II. and III.
I., II., and III.
Theodore claims that droughts are becoming more frequent in the western United States, and that they are causing an increase in wildfires. He also claims that increasing carbon dioxide levels in the atmosphere are the cause of the increased frequency of the droughts.
Could evidence and logical reasoning support Theodore’s claim?
Yes. The increased carbon dioxide levels are causing increased global temperatures, which are affecting all aspects of global climate.
Yes. The increased carbon dioxide levels are directly affecting precipitation patterns, independently of global warming.
No. The increased carbon dioxide levels are causing an increase in temperature, but do not change precipitation patterns.
No. The increased carbon dioxide levels are causing ocean acidification, but do not affect temperature or precipitation.
No. Carbon dioxide levels increase during some years and decrease during other years, so they are not responsible for long-term trends.
Mindy is writing a report on the changes to matter and energy in ecosystems. Which statement is the MOST accurate for her to include in the report?
Both matter and energy cycle endlessly within ecosystems and the environment.
Matter cycles endlessly within ecosystems and the environment, while energy becomes concentrated in the highest trophic levels.
Both matter and energy flow from the environment to producers to a chain of consumers.
Both matter and energy flow from the environment to each individual organism with no intermediates.
Matter cycles endlessly within ecosystems and the environment, while energy flows in one direction only.
A developer proposes to build new houses and roads on land that is now part of Mairead Forest, which is a tract of 120 acres that the county has designated as conservation land. The developer points out that his proposal would keep the size of forested land at 120 acres. However, much of the forest would be divided into small pieces separated by highways, houses, and lawns.
How would the proposed development MOST likely affect the biodiversity of Mairead Forest?
Biodiversity would change minimally, or not at all, because the size of the forested land would remain the same.
Biodiversity would change minimally, or not at all, because the development does not pollute the land.
Biodiversity would decrease, because many animal species depend on large areas of land to survive.
Biodiversity would increase, because evolution would occur faster in the fragmented habitats.
Biodiversity would increase, because the human residents would introduce new species to the forest.
The city government has received a grant to improve its transportation system. Proposals for these improvements include adding lanes to a highway, extending the public transit system, and constructing bicycle paths.
A council member argues that adding lanes to the highway is the sustainable choice because the highway is always crowded, and it is used by the majority of city residents. Which statement BEST evaluates the council member's argument?
The argument is valid, although all of the proposals are sustainable because the city depends on transportation.
The argument is valid because sustainable development meets the needs and desires of city residents.
The argument is not valid because sustainable development promotes the conservation of nonrenewable resources, especially the fossil fuels used by most automobiles.
The argument is not valid because any of the proposals could be sustainable depending on investment costs and operating costs.
The argument is not valid because the needs of city residents do not affect sustainable development.
Which of these laws, if enacted, would be MOST useful for achieving the goal of slowing or stopping the effects of climate change?
laws that reduce the likelihood of oil spills
laws that expand the rate of oil drilling on the ocean floor
laws that reduce the use of lead, mercury, and other heavy metals
laws that reduce the emissions of CFCs (chlorofluorocarbons)
laws that reduce the amount of greenhouse gases released into the atmosphere
Scientists are concerned that human activities are causing an increase in the acidity of ocean water. Which two statements, taken together, BEST explain how ocean acidification is occurring? Select two answer choices.
The use of chlorofluorocarbons (CFCs) is thinning the ozone layer.
The burning of fossil fuels is removing oxygen from the atmosphere.
The burning of fossil fuels is adding carbon dioxide to the atmosphere.
Carbon dioxide from the atmosphere reacts with sea salt to form carbonic acid.
Carbon dioxide from the atmosphere reacts with water to form carbonic acid.
Global climate change can occur at different speeds. Listed below are three possible causes of global climate change. What is the order of their typical speed or rate at which they cause change, from slowest to fastest?
I. an asteroid strike or major volcanic eruption
II. changes to Earth's orbital path or the orientation of Earth's axis
III. changes in human activity, such as the burning of fossil fuels
I, II, III
II, I, III
II, III, I
III, I, II
III, II, I
