Deck 22 (MR): An Introduction to Microbiology and Human Disease

Question 1

Which of the following statements are true of viruses (Select all that apply)?

A)A virus has either DNA or RNA surrounding its protein core.
B)To reproduce,a virus must be within a living cell.
C)Viruses spread from person to person only by direct contact.
D)Viruses cause disease by killing the cells they reproduce within.
E)The enzymes secreted by viruses are needed for them to obtain food.
F)Some viruses require insect vectors to spread from host to host.

Answer 1

B,D,F

Question 2

Which of the following statements are true of portals of entry and exit (Select all that apply)?

A)The reproductive tract is the only portal of entry for the pathogens of sexually transmitted diseases.
B)Even a small break in the stratum corneum is a potential portal of entry for bacteria.
C)The HCl in gastric juice destroys many pathogens that enter with food and drink.
D)There is no direct portal of entry to the human nervous system.
E)The human large intestine is a portal of exit for water-borne diseases such as cholera.
F)The nose is a possible portal of entry,but not a portal of exit.

Answer 2

B,C,D,E

Question 3

Which of the following statements are true of bacteria (Select all that apply)?

A) Bacterial DNA is always in pairs of circular chromosomes.
B) The chemical structure of the cell wall of bacteria is the basis for the Gram stain.
C) A bacterial capsule inhibits phagocytosis by white blood cells.
D) Bacterial flagella permit attachment to a host cell.
E) Many bacterial toxins are enzymes the bacteria use to obtain food.
F) A bacterial spore is a reproductive structure that produces four bacteria from one.
G) “Coccus” is to “sphere” as “bacillus” is to “square.”
H) Anaerobic bacteria do not reproduce in the absence of oxygen.

Answer 3

The chemical structure of the cell wall of bacteria is the basis for the Gram stain.
A bacterial capsule inhibits phagocytosis by white blood cells.
Many bacterial toxins are enzymes the bacteria use to obtain food.

Question 4

Which of the following statements are true of infections and disease (Select all that apply)?

A)When the number of cases of a disease rises sharply,the disease is called endemic.
B)Subclinical is a synonym for asymptomatic or inapparent.
C)Fomites are objects that may be a source of pathogens.
D)An acute infection is always localized,and a chronic infection is always widespread.
E)A communicable disease is not always contagious,and a contagious disease is not always communicable. f.A post-op infection of abdominal skin sutures is an example of a nosocomial infection.

Question 5

Which of the following statements are true of infections and disease (Select all that apply)?

A)An endogenous infection is one that is acquired in a hospital or other institution.
B)A person who has recovered from a disease but remains a source of the pathogen is considered a carrier.
C)When influenza is followed by bacterial pneumonia,the pneumonia is considered a secondary infection.
D)A zoonosis is a disease that affects only wild animals.
E)The "AIDS epidemic" is really the "AIDS pandemic."
F)Septicemia is a systemic infection,and is always serious.

Question 6

Which of the following statements are true of yeasts and molds (Select all that apply)?

A)A superficial mycosis affects the skin or mucous membranes.
B)Yeasts in small numbers may be part of the resident flora of the skin or oral cavity.
C)The molds that form mycelia are not considered part of resident flora.
D)People with compromised immune systems are more susceptible to systemic mycoses.
E)Several systemic mycoses are lung infections following the inhalation of spores.
F)Molds are true pathogens in that they always cause disease whenever they are present.

Question 7

Which of the following statements are true of vectors and the diseases they spread (Select all that apply)?

A)The human body louse is the vector of typhoid fever.
B)Mosquitoes are vectors of malaria and yellow fever.
C)Vectors spread disease when they bite humans or other warm-blooded animals.
D)The deer tick is the vector of Lyme disease and West Nile encephalitis.
E)Fleas are vectors of bubonic plague,epidemic typhus,and sleeping sickness.
F)The vector of a pathogen may be an essential part of the life cycle of that pathogen.

Question 8

Which of the following statements are true of resident flora (Select all that apply)?

A)The nasal cavities have a smaller flora than do the bronchioles.
B)Many of our resident flora prevent pathogens from establishing themselves.
C)Some colon flora produce vitamins that are useful to us.
D)The urinary bladder should have only a small population,and the blood should be free of bacteria.
E)Resident skin flora include fungi as well as bacteria.
F)Few pathogens reach the lungs,and those that do are quickly destroyed by red blood cells.

Question 9

Which of the following statements are true of sterilization and pasteurization (Select all that apply)?

A)Pasteurization is the pathogen-destroying process for milk and milk products.
B)An antiseptic is a chemical that kills pathogens on inanimate surfaces.
C)A disinfectant is a chemical that kills pathogens on the skin or living tissue.
D)Boiling drinking water for a minute will kill most bacteria,but may not kill bacterial spores.
E)Surgical instruments must be sterilized after each use.f.Bleach is an effective bactericide.