Apes Unit 8*

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×1kg2.2lb×13mg1kg×1g1,000mg

A pesticide was applied to a population of roaches, and it was determined that the LD50LD50 was 55mgkg55mgkg. If the average mass of a roach was 0.02kg0.02kg, which of the following approaches will determine the dose in mgmg per roach?

55mg1kg×0.02kg

Based on the data in the graph, which of the following should be used to calculate the difference in LD50LD50 for the two different species of mice?

575mg−490mg

Water from which of the following locations on the map would best serve as a control group for the study?

A

Which is a point source of pollution?

A sewage treatment plan

Which of the following best describes the action of an endocrine disruptor?

An endocrine disruptor blocks the receptor protein binding site of a hormone so that the cell cannot receive a signal

Which of the following best describes why DDTDDT is classified as a persistent organic pollutant?

DDTDDT is very stable, and as much as 50% of the original concentration can remain in the soil 15 years after the initial application.

Researchers suspect that sewage leaked into the Moose River. Rates for which of the following diseases should be used to determine whether the human population using the river as a source of drinking water was exposed to sewage?

Dysentery

Which of the following water quality tests would best indicate if sewage from the wastewater treatment plant has contaminated the Moose River?

Fecal coliform measured at site B

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

Hormones

Mercury concentrations were measured in freshwater shrimp populations in two different ponds, one polluted with mercury and one unpolluted, with a similar food web in each pond. Which of the following best identifies the scientific question that would guide this investigation?

How much mercury accumulates in the tissues of freshwater shrimp living in a polluted pond?

Which of the following is the most likely consequence of runoff transporting chemicals that are endocrine disruptors to a pond?

Increased frequency of birth defects in fish populations in the pond

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

Significant increases in water temperature can drastically change dissolved oxygen (DO)(DO) levels in a lake. Why does the combined effect of these two environmental changes result in algal blooms?

Low dissolved oxygen leads to death for aerobic organisms, like fish, whose decomposition provides an overabundance of nutrients for the algae, resulting in the large blooms.

A scientist is studying PCBsPCBs in tertiary consumers. She wants to determine if PCBsPCBs can be found in tertiary consumers even though these compounds were banned in the United States in the 1970s. Which of the following best identifies a testable hypothesis for the study?

PCBsPCBs are persistent organic compounds that are fat-soluble, so they should be found in the fatty tissues of tertiary consumers even though the compounds have been banned for decades.

Which of the following best explains why top predators can have up to 60 times as much of persistent organic pollutant (POPPOP) as their prey and up to 600 times as much of the pollutant as producers?

POPsPOPs accumulate in the body fat of living organisms. POPsPOPs increase in concentration as they move up the food chain.

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

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

Which of the following solutions would best address the issues of greatest concern in the community?

Planting mangrove forests

Which of the following practices would best help to protect against inland and coastal flooding in urban areas?

Preserving wetland and coastal mangrove habitats

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.

Scientists are interested in determining if selenium, from a nearby mine, magnifies in the tissues of fish living in a lake. Which of the following best describes a testable hypothesis for the study?

Selenium will be at a higher concentration in fish tissue than in the tissue of fish prey.

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

When water used to cool power plants during normal plant operations is released into adjacent waterways, which of the following is most likely to occur as a result?

The dissolved oxygen in the adjacent waterways would decrease because used coolant water is warm and leads to thermal pollution.

A massive bluegill fish kill was observed in a lake near a power plant during the winter months. It was determined that the plant was releasing large amounts of hot water into the lake. Which of the following explains what likely caused the death of so many bluegills in the lake?

The influx of warmer water caused an unexpected increase in the metabolic rate of the bluegills, which led to increased physiological stress from limited resource availability.

Based on the diagram above, which of the following is the most likely reason that V. cholerae can spread rapidly through a population?

V. cholerae is a microscopic bacterium that can survive in various aquatic environments for prolonged periods of time and can cause a delayed onset of visible symptoms

Eutrophication

can cause dead zones.

Fecal coliform bacteria

is used as an indicator of water quality

Leach fields are

used to filter septage

A manure lagoon is being built for a dairy with 700 cows, each of which produces 40 L of manure each day. How large must the lagoon be to hold 30 days' worth of manure?

840,000 L