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03:52
04:23 03:52Which of the following statements is false?
a. E. coli never causes disease
b. E. coli provides vitamin K for its host
c. E. coli often exists in a mutualistic relationship with humans
d. A disease-causing strain of E. coli causes bloody diarrhea
Distinguish symptoms from signs as signals of disease.
All members of a group of ornithologists studying barn owls in the wild have had
salmonellosis (Salmonella gastroenteritis). One birder is experiencing her third infection. What is the most likely source of their infections?
a. The ornithologists are eating the same food.
b. They are contaminating their hands while handling the owls and nests.
c. One of the workers is a Salmonella carrier.
d. Their drinking water is contaminated.
Which of the following is not one of Koch's postulates?
a. The same pathogen must be present in every case of the disease.
b. The pathogen must be isolated and grown in pure culture from the diseased host.
c. The pathogen from pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal.
d. The disease must be transmitted from a diseased animal to a healthy, susceptible animal by direct contact.
e. The pathogen must be isolated in pure culture from an experimentally infected lab animal.
Which one of the following diseases is not correctly matched to its reservoir?
a. Influenza-animal
b. Rabies-animal
c. Botulism-nonliving
d. Anthrax-nonliving
e. Toxoplasmosis-cats
Indicate whether each of the following conditions is typical of subacute, chronic, or acute infections.
a. The patient experiences a rapid onset of malaise; symptoms last 5 days
b. The patient experiences cough and breathing difficulty for months
c. The patient has no apparent symptoms and is a known carrier
