Microbiology- Chapter 22 Homework
Put the steps in the correct order to demonstrate your understanding of water purification and sewage treatment.
Raw Water 1. Coagulation 2. Sedimentation 3. Filtration 4. Disinfection 5. Distribution
Choose the answer that explains the emergence of Lyme disease in the northeastern United States.
Restoration of woodland areas increased the deer tick population, the vector for transmission of Lyme disease to humans.
Increased rainfall in some areas of the world could lead to an increased incidence of which of the following diseases?
-Malaria -Yellow Fever
Which of the following organisms are coliforms?
Enterobacter E.coli Klebsiella All of the choices are coliforms
Which of the following refers to a process in which microbial activity is discouraged? -Composting -Trickling filter system -Bioremediation -All of these activities involve the activity of microbes
-All of the activities involve the activity of microbes
Which pathway accurately represents the spread of West Nile virus in the late 1990s through the 2000s?
Africa—eastern United States—western United States
Complete the sentences to demonstrate your understanding of the 1993 outbreak of hantavirus pulmonary syndrome in the United States.
As weather patterns change, unusual occurrences of infectious disease can result. In 1993, healthy young adults were dying of severe respiratory distress caused by hantavirus infection. The year before this occurred, El Nino had brought wetter winter conditions to the southwestern United States. This led to an increase in pine nuts, which led to an increase in the deer mouse population. These rodents are the reservoirs for hantavirus, and people were infected by inhaling aerosols of rodent urine or feces.
Which of the following emerging pathogens is a spirochete?
Borelia burgdorferi
Using figure 22.2, which of the following zoonoses leads to the most human deaths annually?
Cysticercosis
A xenobiotic is any compound that has been chemically altered to undergo biodegradation. True or False
False
All coliform species are fecal bacteria; therefore, a high total coliform count indicates a substance is absolutely unsafe to drink. True or False
False
The presence of coliforms necessarily indicates the presence of fecal matter. True or False
False
The presence of trace amounts of fecal coliforms in a water sample means that the entire body of water is considered unsafe to drink. True or False
False
Waterborne pathogens are always bacterial in nature and have been known to cause disease epidemics. True or False
False
Which of the following most likely explains the transmission of HIV from animals to humans?
HIV evolved from a similar virus in chimpanzees that was transmitted to hunters by bites, scratches, and blood products.
What type of bacteria is water tested for when determining its safety?
Indicator bacteria
Which of the following xenobiotic chemicals was redesigned to be biodegradable?
Laundry detergents
Which of the following is an emerging or reemerging disease for which a vaccine is widely available?
Measles
Move the diseases to the correct category to demonstrate your understanding of how environmental changes can affect the transmission of different infectious agents.
Rates and Patterns of Infection Change due to Changes in Vector Population Yellow fever West Nile encephalitis Malaria Lyme disease Rates and Patterns of Infection Change Due to Changes in Water quality Cholera Hepatitis A E. Coli
Which of the following is a common pathogen that can cause a waterborne diarrheal illness?
Shigella
Complete the sentences to review the rapid method of water analysis for coliform contamination.
Water quality departments employ some standard assays for the routine detection and quantification of coliforms. These organisms serve as indicator bacteria, meaning that their presence in the water is indicative of recent fecal contamination. In the membrane filter technique, the water sample is passed through a sterile apparatus and collected in a flask. The filter on to which the sample was collected is then placed on a medium that is both differential and selective, such as m-Endo agar. After incubation, the plate medium permits easy differentiation of coliforms that naturally exist in soils and uncontaminated water from true fecal coliforms that live mainly in the intestinal tract of mammals. Other tests, like the MI agar test, detect coliforms based on their ability to ferment lactose in the medium.
