apeskululukulu

The table below shows the number of brine shrimp that hatched over 72 hours in three different concentrations of salt water. All tanks had 50 eggs at the start of the study. Based on the data in the table, which of the following concentrations of sodium chloride is most toxic to brine shrimp? (a) 0mg/100mL (b) 10mg/100mL (c) 20mg/100mL (d) 30mg/100mL

(a) 0mg/100mL

Based on the data in the graph, which of the four chemicals is the most toxic to amphibians regardless of dose? (a) A (b) B (c) C (d) D

(a) A

Which of the following is an example of a point source of pollution? (a) A leaking septic tank (b) Agricultural pollution from a group of cattle farms (c) Runoff following road construction (d) Acid mine drainage

(a) A leaking septic tank

Which of the following approaches would best decrease the impact of frequent flooding in a community that is subject to the hazard of flooding? (a) Construct wetland areas near the rivers and streams. (b) Remove forested areas around all streams and rivers and change land use to agriculture. (c) Increase the height of natural levees downstream from the community. (d) Encourage developers to build housing developments on the floodplain.

(a) Construct wetland areas near the rivers and streams.

Which of the following is the most likely impact of thermal pollution from power plants on a river ecosystem? (a) Decreased oxygen levels because warm water holds less dissolved gas than cold water does (b) Increased sedimentation because minerals precipitate out of the water column in warm water (c) Reduced growth rates of primary producers such as aquatic plants and algae (d) Decreased metabolic rates of aquatic animals exposed to the heated water

(a) Decreased oxygen levels because warm water holds less dissolved gas than cold water does

Scientists are interested in studying the bioaccumulation of mercury in different species of dolphins exposed to the same concentration of mercury. The dolphins in the study will be of similar age and living in the same habitat. Which of the following best identifies a testable hypothesis for the study? (a) Different species of dolphins will have different levels of mercury in their fatty tissues depending on the species' ability to absorb and excrete mercury. (b) Dolphins will have the highest levels of mercury in their fatty tissues when they are exposed to the highest concentration of mercury. (c) Dolphin species that are not exposed to mercury in the water will still have trace levels of mercury in their muscle tissues from exposure through air. (d) The concentration of mercury in the tissues of different species of dolphins is dependent on the life span of the species and on the number of offspring produced.

(a) Different species of dolphins will have different levels of mercury in their fatty tissues depending on the species' ability to absorb and excrete mercury.

Which of the following pollutants would most likely be responsible for gender imbalance in a population of frogs in which all observed frogs are female? (a) Endocrine disruptors (b) Carcinogens (c) Animal waste from farms (d) Fertilizers

(a) Endocrine disruptors

Based on the data in the graph, which of the following likely occurred from 1960 to 2015 because of changes in solid waste disposal methods? (a) Fewer natural resources needed to be extracted. (b) Groundwater contamination declined. (c) Less carbon dioxide was released into the atmosphere. (d) Less land was used for landfills.

(a) Fewer natural resources needed to be extracted.

Which of the following strategies will best help to protect mangrove habitats? (a) Limiting coastal development and maintain a shoreline buffer zone (b) Increasing aquaculture operations to reduce overfishing (c) Increasing subsidies for hydroelectric dam construction (d) Encouraging land use changes in areas surrounding mangroves to shift to agriculture

(a) Limiting coastal development and maintain a shoreline buffer zone

Based on the diagram, which of the following processes most likely caused the fish in the lake to die? (a) The remains of the bottom-dwelling plants and algae decomposed, depleting the amount of oxygen in the water. (b) The algal bloom at the surface released carbon dioxide into the water, suffocating the fish. (c) The herbicides used on the corn crop were washed into the lake, accidentally poisoning the fish. (d) Carbohydrates were released into the water when the bottom-dwelling plants died, increasing the amount of competition for food.

(a) The remains of the bottom-dwelling plants and algae decomposed, depleting the amount of oxygen in the water.

One benefit of solid waste disposal in landfills is that the methane produced from decomposition can be harnessed for energy. Based on the data in the graph, methane production from waste management most likely peaked during which of the following years? (a) 1980 (b) 1990 (c) 2000 (d) 2010

(b) 1990

Which of the following approaches should be used to calculate the amount of lead, in milligrams, that would be present in a population of 200 rats with each rat weighing on average 20 grams, dosed with the LD50 dose. (a) 200rats × 20g/1rat × 1kg/1000g × 150mg/1kg (b) 200rats × 20g/1rat × 1kg/1000g × 100mg/1kg (c) 200rats × 20g/1rat × 1kg/100mg × 1000mg/1kg (d) 200rats ×1rat/20g × 1kg/1000g × 150mg1kg

(b) 200rats × 20g/1rat × 1kg/1000g × 100mg/1kg

Which of the following approaches would you use to calculate the amount of pesticide, in milligrams per gram of bees? (a) 78ng/bee × 1bee/0.1g × 1,000,000ng/1mg (b) 78ng/bee × 1bee/0.1g × 1mg/1,000,000ng (c) 78ng/bee × 1bee/50 × 1,000,000ng/1mg (d) 78ng/bee × 1bee/1,000,000ng × 50%

(b) 78ng/bee × 1bee/0.1g × 1mg/1,000,000ng

A biologist is studying a small food web in which phytoplankton are eaten by krill, krill are eaten by fish, and fish are eaten by seals. During their study of the ecosystem, the biologist discovers that PCBs are present in measurable levels in the water and wants to examine how PCBs could vary in different trophic levels. Which of the following best identifies a testable hypothesis for the study? (a) Biomagnification will cause the phytoplankton to have the highest amount of PCBs in their tissues. (b) Biomagnification will cause the seals to have the highest amount of PCBs in their tissues. (c) Bioaccumulation will cause the seals to have the highest amount of PCBs in their tissues. (d) Bioaccumulation will cause the fish to have the highest amount of PCBs in their tissues.

(b) Biomagnification will cause the seals to have the highest amount of PCBs in their tissues.

Which of the following best describes the source of persistent organic pollutants (POPs) that could accumulate in the tissues of a top predator? (a) Methane (CH4) and carbon dioxide (CO2) released from livestock operations (b) DDT and other pesticides that are sprayed to control for mosquitoes (c) CFCs that are manufactured to be used as pesticides (d) Sulfur dioxide (SO2) released from coal-burning power plants

(b) DDT and other pesticides that are sprayed to control for mosquitoes

A scientist wants to study the effect of DDT in a fish-eating bird species. She measures a variety of variables in a population of birds over a period of ten years to determine how levels of DDT affect bird survival and reproduction. Which of the following identifies a scientific question she could ask to best evaluate the effect of DDT on the bird species? (a) Is the bird species able to metabolize DDT faster than the fish the birds consume? (b) Does the persistence of DDT lead to eggshell thinning or developmental deformities in the bird species? (c) Has the decrease in DDT usage led to a decrease in DDT concentration in the tissues of fish-eating birds? (d) How long does it take for DDTDDT to break down once it is absorbed in the fatty tissues of the fish-eating birds?

(b) Does the persistence of DDT lead to eggshell thinning or developmental deformities in the bird species?

Based on the pathways shown in the diagram, which of the following best describes how climate change will most likely increase the transmission rates of the Zika virus? (a) A decrease in the number of baboons will lead to an increase in human exposure to the virus. (b) Expanded mosquito ranges will increase human exposure to the virus. (c) A shift in the human population to urban areas will decrease transmission between people. (d) Desertification will cause an increase in the number of monkeys and chimpanzees, which will decrease the overall number of cases of Zika.

(b) Expanded mosquito ranges will increase human exposure to the virus.

Based on the diagram, which of the following is the vector that transmits the Zika virus to humans? (a) Chimpanzees (b) Mosquitoes (c) Tree pollen (d) Urban areas

(b) Mosquitoes

According to the World Health Organization, persistent organic pollutants (POPs) are found in nearly all tested organism tissues and environmental samples. Which characteristic of POPs accounts for their presence in living tissues and in environmental samples? (a) POPs are lipophilic, which means that they can be stored in fatty tissues for long periods of time. (b) POPs are released in to the air, water, and land, which allows them to be transported and incorporated in multiple ways. (c) POPs are synthetic chemicals, so only humans and urban environments are exposed to the pollutants. (d) POPs are organic compounds, so they can biodegrade easily and move through various environments.

(b) POPs are released in to the air, water, and land, which allows them to be transported and incorporated in multiple ways.

The diagram below depicts a surface water source that has undergone cultural eutrophication. Based on the diagram, which of the following processes most likely caused the algal bloom in the lake? (a) The water table rose and caused widespread flooding in the area. (b) Runoff carried excess fertilizer from the cornfield into the water. (c) Excess oxygen was released into the water when the fish died. (d) Decomposition of the dead algae used up all the dissolved carbon dioxide.

(b) Runoff carried excess fertilizer from the cornfield into the water.

Which of the following would best be described as a point source of pollution from a farm? (a) Nitrogenous fertilizers added to drip irrigation used for growing crops (b) Runoff from the waste lagoons of Concentrated Animal Feeding Operations, which enters local waterways after a flooding event (c) Tractors and harvesters burning fossil fuels and releasing carbon dioxide and nitrous oxides into the atmosphere (d) Particulate matter from bare soil on plowed fields entering the atmosphere from wind

(b) Runoff from the waste lagoons of Concentrated Animal Feeding Operations, which enters local waterways after a flooding event

Which of the following statements best describes how the Clean Water Act legislation aims to protect wetlands from being lost? (a) The Clean Water Act bans the draining of wetlands over five acres in size. (b) The Clean Water Act requires wetlands to be constructed to mitigate the effect of newly drained wetlands. (c) The Clean Water Act establishes standards for the quality of surface waters that must be continually monitored and reported. (d) The Clean Water Act prohibits the use of wetlands for development and construction.

(b) The Clean Water Act requires wetlands to be constructed to mitigate the effect of newly drained wetlands.

Which of the following best describes why persistent organic pollutants (POPs) are toxic to organisms? (a) They emit gamma radiation, increasing the likelihood of mutations and cancer. (b) They do not break down easily and can accumulate in the fat tissue of an organism. (c) They are easily dispersed by wind and water, greatly increasing the affected areas. (d) They are naturally occurring in the soil and water; therefore, they easily contaminate the food web.

(b) They do not break down easily and can accumulate in the fat tissue of an organism.

At what step in the diagram would the last solid waste be removed from the wastewater in the treatment plant? (a) A - screening (b) B - settling (c) C - filtration (d) D - discharge or treatment

(c) C

Which of the following best describes the action of endocrine disruptors in organisms? (a) Endocrine disruptors scar the lung tissue of animals, inducing respiratory difficulties. (b) Endocrine disruptors block the central nervous system of animals, leading to behavioral abnormalities. (c) Endocrine disruptors mimic naturally occurring hormones in animals, leading to developmental disorders. (d) Endocrine disruptors reduce primary productivity in plants, inducing a trophic cascade.

(c) Endocrine disruptors mimic naturally occurring hormones in animals, leading to developmental disorders.

A scientist is studying the correlation between air pollution and cardiovascular disease in humans. Which of the following measures would best show a link between air pollution and cardiovascular disease? (a) Mortality rates from cardiovascular disease in populations in different countries (b) Total number of emergency room visits by individuals with cardiovascular disease in urban areas compared to rural areas (c) Occurrences of emergency room visits by individuals with cardiovascular disease on days with a high air quality index value (d) Change in number of individuals with cardiovascular diseases over the past 50 years compared to levels of atmospheric carbon dioxide

(c) Occurrences of emergency room visits by individuals with cardiovascular disease on days with a high air quality index value

Which of the following correctly identifies an example of an endocrine disruptor and the effect it might have on the human body? (a) High levels of lead in drinking water could lead to neurological damage. (b) Exposure to radon in indoor air is linked to increased rates of lung cancer. (c) Phthalates in cosmetics and shampoos reduce fertility. (d) The bacterium E. coli found in vegetables causes abdominal cramping and vomiting.

(c) Phthalates in cosmetics and shampoos reduce fertility.

Based on the diagram, organic solids that have settled to the bottom of the treatment tanks in step B are transferred to which of the following for further processing? (a) Screens (b) Filter beds (c) Sludge treatment tanks (d) Effluent discharge

(c) Sludge treatment tanks

Based on the diagram, which of the following processes most likely caused the bottom-dwelling plants in the lake to die? (a) The remnants of the corn crop were burned after the corn was harvested, decreasing the amount of dissolved oxygen in the water. (b) Toxins such as lead and mercury were released into the water when the fish died. (c) The algal bloom prevented sunlight from reaching the bottom-dwelling plants, which reduced the rates of photosynthesis. (d) Oxygen was released into the water when the algae died.

(c) The algal bloom prevented sunlight from reaching the bottom-dwelling plants, which reduced the rates of photosynthesis.

Which of the following describes the independent variable in the experiment? (a) The simulated field environment that housed the group of twenty mice (b) The respiratory output of each mouse (c) The different levels of ozone introduced into the environments (d) The use of female mice

(c) The different levels of ozone introduced into the environments

Which of the following best describes how thermal pollution from power plants can affect aquatic ecosystems? (a) Water injected into the ground during the hydraulic fracking process can seep into wells, causing methane contamination. (b) Warm water runoff that reaches lakes and ponds slows down the metabolic rate of aquatic animals, which decreases primary productivity. (c) Warm water discharged into rivers and streams decreases the oxygen content of the water, which reduces the number of fish species. (d) Wastewater from nuclear power plants contains radioisotopes and carbonic acid, which increase the rate of cancer in aquatic species.

(c) Warm water discharged into rivers and streams decreases the oxygen content of the water, which reduces the number of fish species.

Based on the LD50 data in the table, which of the following equations should be used to calculate how many times greater the resistance of a rabbit to x-rays is than that of a dog? (a) 800−325 (b) 800+325 (c) 800×325 (d) 800/325

(d) 800/325

Which of the following should be added to the study to best serve as the control group? (a) A replicated experiment using male mice (b) A replicated experiment conducted in the field and not in the laboratory (c) A group of twenty mice provided with additional food resources (d) A group of twenty mice that were not exposed to ozone

(d) A group of twenty mice that were not exposed to ozone

At what step in the diagram would wastewater most likely be treated with chlorine or UV light to remove bacteria? (a) Before step A (screening) (b) Between steps A and B (screening and settling) (c) Between steps C and D (filtration and discharge or treatment) (d) During step D (discharge or treatment)

(d) During step D (discharge or treatment)

Based on the diagram, which of the following is one way that the Zika virus can be spread within the human population? (a) Airborne transmission (b) Through drinking water (c) Through contaminated food (d) From a mother to her unborn child

(d) From a mother to her unborn child

Based on the data in the graph, which of the following solutions most likely led to the decrease in the amount of waste sent to landfills from 1990 to 2015 ? (a) Increased composting of domestic waste (b) Increased composting of e-waste (c) Increased combustion of waste (d) Increased recycling of waste

(d) Increased recycling of waste

The table below shows the number of brine shrimp that hatched over 72 hours in three different concentrations of salt water. All tanks had 50 eggs at the start of the study. Which of the following claims about brine shrimp is best supported by the data in the table? (a) Brine shrimp generally hatch in 36 to 48 hours in warm temperatures. (b) The growth and survival of brine shrimp are optimal 72 hours after hatching. (c) There is more food available for brine shrimp when the water has a salt concentration of 20mg100mL. (d) The optimal salinity for brine shrimp hatching is 30mg100mL.

(d) The optimal salinity for brine shrimp hatching is 30mg100mL.

<prior description> Which of the following best explains why the die-off event occurred in the lake following the increased water temperature? (a) The warm water increased the amount of dissolved oxygen in the water, which led to an increase in the photosynthetic rate of the aquatic organisms. (b) The warm water increased the amount of dissolved oxygen in the water, which led to an increase in the amount of competition by consumers for food. (c) The warm water decreased the amount of dissolved oxygen in the water, which led to an increase in the rate of decomposition in the lake. (d) The warm water decreased the amount of dissolved oxygen in the water, which led to an increase in the respiration rate of the aquatic organisms.

(d) The warm water decreased the amount of dissolved oxygen in the water, which led to an increase in the respiration rate of the aquatic organisms.

Which of the following correctly identifies both a non-point source and a point source of pollution? (a) Industrial smokestack - Waste discharge pipe (b) Agricultural runoff - Urban runoff (c) Leaking sanitary landfill - Pesticide spraying (d) Urban runoff - City bus exhaust

(d) Urban runoff - City bus exhaust