Unit 8 Quiz

This pathogen is primarily transmitted by mosquitoes and is found most often in sub-Saharan Africa.

zika

In August of 2014, residents of several Ohio cities that use Lake Erie as a drinking water source were warned not to drink tap water because of the presence of toxins released by blue-green algae (cyanobacteria). Which of the following is the most likely cause of recent blooms of blue-green algae in Lake Erie?

Chlorine from sewage treatment plants along Lake Erie's shoreline

For a certain insecticide, the LD-50 dosage level for rats is determined to be 250 milligrams per kilograms of body mass. On the basis of this information, which of the following is the best prediction regarding the consequences of receiving this dosage of the insecticide?

Five hundred out of every one thousand rats would die.

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

Runoff from agricultural fields

In 1986 Country X established regulations to reduce the maximum allowable concentration of chromium in industrial effluents from 37 ppm to 25 ppm. In 1994 government research indicated that a chromium concentration of up to 35 ppm in effluents presented an acceptable risk; in the same year the government also discovered that a certain chemical company had been discharging effluents with chromium concentrations of 32 ppm each year since 1981. Based on this information, which of the following statements is correct?

The chemical company did not violate effluent regulations in the 1982-1985 period, but it violated them at some other time.

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.

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

a lack of sufficient minerals in the water

Which method introduces microorganisms to break down hazardous organic compounds in wastewater treatment?

biological treatment

Some toxic compounds are ingested and retained in the tissues. These pollutants pose special risks to humans and other organisms high on the food chain because of which process?

biomagnification

Factors that increase the spread of infectious diseases include all of the following EXCEPT

exposure to neurotoxins, which affect the endocrine system

Which of the following poses a health risk to humans who eat large quantities of marine fish such as swordfish and tuna?

mercury

Although the use of DDT was banned in the United States in 1972, a test of the body tissue of an average United States resident today would most likely reveal the presence of DDT because

other countries that export produce to the United States still use DDT

Which of the following is an effective alternative to chlorine for disinfecting wastewater in a municipal treatment plant?

ozone

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