APES Ch8

The LD50 for arsenic in humans is 13mg/kg. Which of the following approaches should be used to calculate the number of grams of arsenic it would take to reach the LD50 in a 140-pound person? [Note: 1kg=2.2pounds]

140lb x 1kg/2.2lb x 13mg/1kg x 1g/1000mg First, pounds are converted to kilograms, then the kilograms are multiplied by the given amount of 13mg/kg to find amount of arsenicto reach the LD50. Since it gives in milligrams, milligrams must be converted to grams for the final answer.

Which of the following describes a component of a modern sanitary landfill?

A bottom liner of plastic or clay to prevent groundwater contamination

When scientists discover the existence of an emerging infectious disease such as SARS (severe acute respiratory syndrome), they must take immediate steps to determine the cause of the disease and the method of transmission. These initial steps would include which of the following?

Acquiring recent medical and travel histories of the disease victims

An ecologist examining several different ponds discovers that in one pond all the frogs are female. Which of the following most likely led to the all-female population of frogs?

An endocrine disrupter

Which of the following is most likely to result from destruction of wetlands surrounding a river?

An increased frequency of flooding of the river valley

Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case.

As the concentration of anastrozole increases, the percent induction of breast cancer decreases.

The graph above shows the effect of sewage on biological oxygen demand (BOD) and dissolved oxygen (DO) in a flowing stream. The smallest fish populations will most probably be found at point?

C

Which of the following best explains why DDT has been found in penguin eggs in the Antarctic?

Chemicals used in one region of Earth can circulate in the biosphere and affect organisms in a distant region.

This pathogen infects the intestine and is spread through contaminated water or food

Chlorea

This pathogen infects the intestine and is spread through contaminated water or food.

Cholera

Directions: Select the choice that best fits each statement. The following question(s) refer to the following. (A) Safe Drinking Water Act (B) Clean Water Act (C) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (D) Resource Conservation and Recovery Act (E) Toxic Substances Control Act Mandates the restoration and maintenance of the chemical, physical, and biological integrity of the nation's waters

Clean Water Act

Which of the following is the most likely route for mercury to enter the food web?

Coal-burning emissions → deposition → ocean → plankton → fishes

The graph below represents the dose response curves of insect pests for four different pesticides.

D(kill 100%)

Alligators in a Florida lake polluted by high levels of dioxins (chlorinated hydrocarbons) had low testosterone levels and failed to reproduce. Scientists came to the conclusion that the dioxins were acting as which of the following?

Endocrine disrupters

Of the following, which is the best example of a point source of water pollution?

Factory effluent

The presence of which of the following contaminants would be the strongest reason for judging municipal sewage sludge unfit for use as fertilizer?

Heavy Metals

Endocrine disruptors directly affect which of the following in an organism?

Hormones

Regulations that deal directly with the disposal of hazardous materials in the United States include which of the following? I RCRA II Clean Water Act III Clean Air Act

I only

Which of the following is a common characteristic of lakes undergoing cultural eutrophication?

Increased levels of plant nutrients

Which of the following is a way to potentially eliminate one of the greatest threats to the world's mangrove wetlands?

Integrate ecologically sound shrimp aquacultural practices with mangrove management.

Directions: Select the choice that best fits each statement. The following question(s) refer to the following gases. Carbon dioxide Carbon monoxide Methane Radon Sulfur dioxide Is a flammable gas produced by landfills

Methane

Which of the following is the best example of a point source pollutant?

Oil tanker spill

Step P. Water is passed through a screen to remove debris. Step Q. Pathogenic organisms are killed by chlorination, UV, or ozone. Step R. Suspended particles clump and settle out. Step S. A floccing agent, such as alum, is added to the water. The processes described above are steps in the purification and treatment of municipal wastewater. The steps are listed in random order. Which of the following lists the steps in the correct sequence?

P → S → R → Q

Which of the following best describes a way that persistent organic pollutants (POPs) cause harm in the environment?

Persistent organic pollutants are soluble in fat, so they accumulate in an organisms' fatty tissues.

Which of the following will result in accelerated eutrophication when introduced into streams, lakes, and bays?

Phosphates

Cholera is an acute infection of the digestive system that is caused by the bacterium Vibrio cholerae. Infected individuals can experience a range of symptoms, including diarrhea, vomiting, muscle cramps, low blood pressure, rapid heart rate, and extreme thirst. If symptoms persist and severe dehydration results, an infected individual can die within hours of symptom onset. The diagram below shows how cholera is transmitted.Based on the diagram, which of the following is the most likely reason that a community with good sanitation could still have individuals who contract cholera?

Runoff from a nearby agricultural field pollutes a reservoir used for drinking water.

Waste from which of the following is an example of nonpoint source pollution

Runoff from agricultural fields

Directions: Select the choice that best fits each statement. The following question(s) refer to the following. (A) Safe Drinking Water Act (B) Clean Water Act (C) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (D) Resource Conservation and Recovery Act (E) Toxic Substances Control Act Requires minimum safety standards for community water supplies

Safe Drinking Water Act

Many synthetic chemicals, such as PCBs, act as estrogen mimics. In an ecosystem, these persistent chemicals would have the greatest effect on which of the following?

Secondary consumers

Which of the following is the best description of bioaccumulation?

The absorption of a substance by an organism at a rate greater than the rate of elimination

A laboratory experiment was done to show the effects of organic waste on the dissolved oxygen (DO) content in water. Five tanks were set up, each containing fresh water and a small amount of single-celled green algae. Specified amounts of organic waste were added to the tanks. The results below show the amount of DO in each tank after a period of one week.Why did the DO after one week decrease as the amount of waste increased?

The algae multiplied and then died and decomposed.

Cholera is an acute infection of the digestive system that is caused by the bacterium Vibrio cholerae. Infected individuals can experience a range of symptoms, including diarrhea, vomiting, muscle cramps, low blood pressure, rapid heart rate, and extreme thirst. If symptoms persist and severe dehydration results, an infected individual can die within hours of symptom onset. The diagram below shows how cholera is transmitted.Based on the diagram above, which of the following best describes why a population in an area that has poor sanitation can be particularly at risk for a cholera outbreak?

The bacterium that causes cholera is spread through ingestion of contaminated water or food.

Glyphosates are herbicides that are often applied to genetically modified (G M) crops to kill weeds without harming the crop itself.Some studies have indicated that global amphibian populations are declining and that exposure to herbicides in agricultural runoff is implicated in the decline. Which of the following is the most likely explanation of how herbicides affect amphibians?

The herbicides act as endocrine disruptors.

Which of the following is true of sewage treatment plants in the United States?

They are not designed to remove pharmaceutical chemicals from wastewater

examples includes both a point and a nonpoint source of pollution?

Waste from animal feedlots and sediment from construction sites AND Fertilizer from suburban lawns and wastewater from a water treatment plant

A local citizen science group is monitoring the water quality of a nearby lake. They gather water samples once a week on Wednesday between the hours of 7 A.M. and 9 A.M. from the same location. One day in August they were unable to sample within that time frame and collected the sample at 3 P.M. How might this modification to the sampling procedure affect the results?

Water sampled later in the day may be warmer and therefore have lower dissolved oxygen levels.

A point source of pollution is something that

a pollution source can be directly attributed to

All of the following are commonly used to deal with the side effects of eutrophication in lakes EXCEPT

adding nitrates

Eutrophication results in the death of trout and other fish as a result of

asphyxiation from lack of oxygen

Most plastics pose a special problem in the waste stream because they

decompose slowly, if at all, and persist as solid waste

Select the all ways in which sediment pollution in water affects the ecosystem

decreases temperature, decreases photosynthesis, Decreases gill function in fish

One of the greatest concerns about POPs, both PCB and DDT, is that they are

fat soluble therefore stay within organisms forever

Although ozone in the stratosphere has been decreasing in recent years, ozone near Earth's surface is on the increase. The ozone near the surface is undesirable because it

is a strong oxidant and a respiratory irritant

Lakes that are characterized by high water clarity and low concentrations of dissolved nutrients are classified as

oligotrophic

A species with a wide range of tolerance allows its to (select all that apply)

survive changing conditions better, handle pollution better, handle climate change better

Of the phenomena that correlate with the data above, the one that is the most direct consequence of the trend in air travel is

the increase in the spread of infectious diseases