WCU micro 9, 10, 14, 15, 16, 19, 20 , 21

The removal of ALL microbes in or on an object is known as ___

A. pasteurization

B. sterilization

C. disinfection

D. sanitizing

B. sterilization

Antiseptics are disinfectant chemicals applied to ___

A. utensils

B. medical devices

C. skin

D. food

C. skin

Which statement MOST accurately describes the microbial death rate after cells are exposed to a microbicidal agent?

A. microbial agents kill a constant percentage of cells over time

B. as soon as a population of cells is exposed to a microbicidal agent, they all die at the same time

C. microbicidal agents do not kill microorganisms, but rather temporarily inhibit their growth

D. the microbial death rate is not constant

A. microbial agents kill a constant percentage of cells over time

How does the alteration if a microbe's cytoplasmic membrane by an antimicrobial agent lead to cell death?

A. the compromised membrane allows viruses to infect the cell, and the cell dies

B. the cell fills with water until it bursts

C. the cell is not able to conjugate

D. cellular contents will leak out of the cell, leading to cell death

D. cellular contents will leak out of the cell, leading to cell death

_____ facilities require that all manipulations be performed in a safety cabinet with HEPA filtration

A. BSL-1

B. BSL-2

C. BSL-3

D. BSL-4

C. BSL-3

What is the first thing you should do to control microbial growth on a surgical instrument that is covered with blood?

A. soak the instrument in disinfectant

B. immediately immerse the instrument in bleach

C. clean the blood off the instrument, then proceed to sterilize it

D. throw the instrument away because it has blood on it

C. clean the blood off the instrument, then proceed to sterilize it

Common methods of using moist heat to control microbial growth include all if the following EXCEPT which one?

A. pasteurization

B. autoclaving

C. boiling

D. incineration

D. incineration

The mechanisms of cell death by moist heat include which of the following?

A. denaturing of proteins

B. creation of thymine dimers

C. disruption of cytoplasmic membranes

D. both denaturing of proteins and disruption of cytoplasmic membranes

D. both denaturing of proteins and disruption of cytoplasmic membranes

Which of the following procedures should be used to sterilize a protein solution?

A. boiling

B. autoclaving

C. filtration

D. nonionizing radiation

C. filtration

Why is a solution of 70% to 90% alcohol more effective at denaturing proteins than 100% alcohol?

A. water is required to denature proteins

B. 100% alcohol is too flammable

C. phenol is used to dilute the alcohol and is more effective

D. 100% alcohol is the most effective

A. water is required to denature proteins

_____ are antimicrobial chemicals produced naturally by microorganisms

A. plasmids

B. antibiotics

C. phages

D. macrophages

B. antibiotics

Which category of chemical agent is placed in newborn's eyes to prevent blindness caused by Neisseria gonorrhoeae?

A. phenols

B. heavy metals

C. alcohols

D. surfactants

B. heavy metals

A phenol coefficient greater than 1 indicates that an agent is ____

A. less effective than phenol

B. more effective than phenol

C. effective after 1 minute

D. less effective than phenol and is effective after 1 minute

B. more effective than phenol

the current standard test in the U.S. for measuring efficacy of disinfectants and antiseptics is the ____ test

A. in-use

B. Kelsey-Sykes capacity

C. phenol coefficient

D. use-dilution

D. use-dilution

Which of the following microorganisms are MOST resistant to antimicrobial agents?

A. bacteria

B. fungi

C. mycobacteria

D. viruses

C. mycobacteria

Who was the FIRST person to envision the use of chemicals to selectively kill pathogens without harming the patient?

A. Louis Pasteur

B. Alexander Fleming

C. Robert Koch

D. Paul Ehrlich

D. Paul Ehrlich

Which of the following was the FIRST antimicrobial agent used to safely treat a wide array of bacterial infections?

A. sulfanilamide

B. arsenic

C. penicillin

D. aspirin

A. sulfanilamide

Which of the following BEST describes why it is difficult to develop antiviral drugs?

A. antiviral drugs are very easy to develop and have no side effects

B. viruses are hard to target because they use the host cell's enzymes and ribosomes to metabolize and replicate

C. viruses are too small to be targeted by drugs

D. viral infections usually clear up on their own with no problems

B. viruses are hard to target because they use the host cell's enzymes and ribosomes to metabolize and replicate

The mechanism of ____ is to inhibit the formation of the peptidoglycan layer in the bacterial cell wall

A. penicillin

B. cephalosporin

C. beta-lactams

D. all of the above

D. all of the above

What is one disadvantage associated with the use of broad-spectrum antibiotics?

A. they kill pathogens too quickly

B. they cause toxicity for the host

C. they cannot be used orally

D. they kill normal microbiota

D. they kill normal microbiota

What is the minimum inhibitory concentration (MIC)?

A. the smallest zone of inhibition

B. the smallest dose of an antimicrobial agent that can be given orally to a patient

C. the smallest amount of bacteria that will be killed by an antimicrobial agent

D. the smallest amount of drug that will inhibit the growth and reproduction of a pathogen

D. the smallest amount of drug that will inhibit the growth and reproduction of a pathogen

Which term best describes an agent that kills microbes, as opposed to temporarily inhibiting their growth and reproduction?

A. bactericidal

B. bacteriostatic

C. toxigenic

D. broad-spectrum

A. bactericidal

Why should tetracycline NOT be prescribed to pregnant women?

A. it can be absorbed into the fetus

B. it can lead to malformation of the skull

C. it can weaken tooth enamel

D. all of the above are correct

D. all of the above are correct

____ is a relationship in which both members benefit

A. mutualism

B. commensalism

C. antagonism

D. symbiosis

A. mutualism

Which of the following is an example of mutualism?

A. Staphylococcus epidermidis living on human skin

B. bacteria living in the human colon

C. tapeworms living in the human colon

D. fleas living on a dog

B. bacteria living in the human colon

Microorganisms that are able to colonize the skin or mucosal surfaces for a limited period of time are called _____

A. parasites

B. transient microbiota

C. commensals

D. resident microbiota

B. transient microbiota

Humans acquire normal microbiota in all of the following ways EXCEPT which one?

A. during first meals

B. during first breaths

C. during birth

D. in the womb

D. in the womb

What can cause normal microbiota to become opportunistic pathogens?

A. hormonal changes

B. stress

C. immune supression

D. all of the above

D. all of the above

What is a zoonotic disease?

A. a disease that affects only exotic animals, not domesticated ones

B. a disease that can spread from animals to humans

C. a disease that can spread from zookeepers to animals

D. a disease that can spread only from humans to animals, not from animals to humans

B. a disease that can spread from animals to humans

Which of the following is TRUE of a disease carrier?

A. carriers never develop disease

B. most carriers have a weakened immune system

C. some carriers never become sick

D. both A and B are correct

C. some carriers never become sick

The term that applies when the presence of a pathogen results in damage to the host is ___

A. infection

B. disease

C. synergy

D. antagonism

B. disease

What is the term used to describe characteristics of a disease that are felt by the patient?

A. symptoms

B. signs

C. objective manifestations

D. syndrome

A. symptoms

Which term describes a disease that is acquired in a healthcare setting?

A. idiopathic

B. nosocomial

C. congenital

D. neoplastic

B. nosocomial

Why are bacterial capsules effective as virulence factors?

A. capsules are toxic to the host cells

B. capsules frant pathogens motility

C. capsules allow pathogens to reproduce faster within the host

D. capsules enable pathogens to "hide" from the immune system

D. capsules enable pathogens to "hide" from the immune system

Which of the following types of toxins are produced only by Gram-negative bacteria?

A. endotoxins

B. cytotoxins

C. neurotoxins

D. enterotoxins

A. endotoxins

Which of the following is a definition of disease transmission by fomites?

A. transmission by inanimate objects

B. transmission by tiny arthopods

C. transmission by the bite of a flea

D. transmission by person-to-person contact

A. transmission by inanimate objects

When a housefly walks across feces containing Salmonella and then walks across food, the fly is serving as a ________.

A. vehicle

B. biological vector

C. mechanical vector

D. fomite

C. mechanical vector

What type of disease develops rapidly but lasts only for a short time?

A. noncommunicable

B. chronic

C. latent

D. acute

D. acute

What term best describes the total number of disease cases in an area during a given period of time?

A. mortality

B. morbidity

C. prevalence

D. incidence

C. prevalence

Which of the following BEST describes an exogenous nosocomial infection?

A. an exogenous infection that is acquired from the healthcare environment

B. an exogenous infection that is acquired outside the hospital

C. an exogenous infection that results from use of medical devices

D. an exogenous infection that results from contact with sick doctors and nurses

A. an exogenous infection that is acquired from the healthcare environment

The careful examination of data used to identify a cause or mode of transmission following an outbreak of disease is called ___ epidemiology

A. descriptive

B. analytical

C. experimental

D. disease

B. analytical

Iatrogenic infections are the result of ___

A. infections acquired by healthcare workers

B. vectors

C. stepping on a nail

D. invasive medical procedures

D. invasive medical procedures

Which of the following does NOT contribute to the ability of the epidermis to act as a nonspecific disease?

A. constant presence of T cells

B. acts as a physical barrier

C. continual cell turnover

D. presence of dendritic cells

A. constant presence of T cells

Which statement BEST describes the environment of the skin and its effect on microbial growth?

A. the skin is simply a physical barrier that keeps microbes from entering the body

B. the skin has minimal defenses, and it is a suitable environment for many microbes

C. salt, defensins, enzymes, and a low pH make the skin inhospitable for ALL microbes

D. the skin is inhospitable to most microbes, but some normal microbiota are present

B. the skin has minimal defenses, and it is a suitable environment for many microbes

Which of the following is NOT a way that normal microbiota help protect the body from pathogens?

A. they consume available nutrients

B. they can alter the pH

C. they keep the immune system stimulated and ready

D. they attack and kill pathogenic microbes

D. they attack and kill pathogenic microbes

Which of the following is a function of normal microbiota?

A. consuming nutrients required by pathogens

B. producing mucus to trap pathogens

C. generating antibodies against pathogens

D. the stomach is not a barrier to infection

A. consuming nutrients required by pathogens

How does the stomach pose a barrier to infection?

A. the grinding action of the stomach lyses pathogens

B. the stomach is a center of immune activity

C. the very acidic pH of the stomach kills most potential pathogens

D. the stomach is not a barrier to infection

C. the very acidic pH of the stomach kills most potential pathogens

Which of the following is TRUE of macrophages?

A. they are part of the second line of defense

B. they are phagocytic

C. they devour foreign objects

D. All of the above

D. All of the above

Which of these statements accurately describes phagocytosis?

A. all cells carry out phagocytosis

B. pathogens are killed in phagolysosomes by acid and oxidative radicals

C. phagocytosis is inhibited by opsonins

D. the purpose of phagocytosis is to transport nutrients in the blood

B. pathogens are killed in phagolysosomes by acid and oxidative radicals

What is the role of a dendritic cell?

A. to secrete toxins against viruses

B. to phagocytize invading cells and act as messenger to cells of active immunity

C. to release histamine

D. to bind iron and inhibit microbial growth

B. to phagocytize invading cells and act as messenger to cells of active immunity

Which pathway of complement activation acts in conjunction with the action of antibiotics?

A. classical pathway

B. alternative pathway

C. lectin pathway

D. attack pathway

A. classical pathway

Which of the following statements is TRUE?

A. acute inflammation can lead to tissue damage and disease

B. chronic inflammation can lead to tissue damage and disease

C. chronic inflammation leads to vessel constriction and decreased permeability of blood vessels

D. acute inflammation results in reduced edema and pain

B. chronic inflammation can lead to tissue damage and disease

What is the physiological trigger for a fever?

A. pyrogens

B. complement

C. interferons

D. bradykinin

A. pyrogens

____ are cells that give rise to lymphocytes

A. epidermal cells

B. erythrocytes

C. plasmacytic stem cells

D. hematopoietic stem cells

D. hematopoietic stem cells

What is the role of primary lymphoid organs in adaptive immunity?

A. antigens arise and mature in these organs

B. antibodies arise and mature in these organs

C. lymphocytes arise and mature in these organs

D. lymph nodes migrate out of these organs

C. lymphocytes arise and mature in these organs

What is the main function of B lymphocytes?

A. to secrete soluble antibodies

B. to attack intracellular pathogens

C. to activate T lymphocytes

D. to activate antigen-presenting cells

A. to secrete soluble antibodies

Toxins and flagella are classified as _____ antigens

A. endogenous

B. exogenous

C. auto

D. hematophagous

B. exogenous

Which type of lymphocyte is responsible for killing abnormal or virus-infected cells?

A. B lymphocyte

B. helper T cell

C. cytotoxic T cell

D. plasma cell

C. cytotoxic T cell

______ is the most common and longest-lasting class of antibody in the blood

A. IgG

B. IgM

C. IgE

D. IgA

A. IgG

What is the benefit of memory T cells that remain in the lymphoid tissues for years after an infection?

A. they are readily available for quick antibody production

B. they are readily available to activate by APCs

C. they provide a quick response without the need for interaction with APCs

D. memory T cells are not beneficial

C. they provide a quick response without the need for interaction with APCs

Which statement regarding memory B cells is MOST accurate?

A. they last 2 - 3 weeks in lymphoid tissues

B. their main function is to constantly secrete antibodies

C. they can last up to 20 years in lymphoid tissues

D. they activate T cells upon a reinfection event

C. they can last up to 20 years in lymphoid tissues

How is a secondary immune response different from a primary immune response?

A. it is faster and more effective

B. it is slower but more effective

C. it is faster but less effective

D. there is no difference

A. it is faster and more effective

Immunity that is passed from a mother to child through the placenta is which type of immunity?

A. naturally acquired active immunity

B. naturally acquired passive immunity

C. vaccination

D. exposure to a pathogen in the environment

B. naturally acquired passive immunity

Which class of antibody is able to cross the placenta from mother to developing fetus?

A. IgG

B. IgM

C. IgE

D. IgA

A. IgG

Jim was given antitoxin to rattlesnake venom when he was seven, and now at age nine, he has been bitten by a rattlesnake. Will he be protected?

A. yes, antitoxin is active immunity

B. no, passive immunity does not have memory

C. no, active immunity wears off in 2 years

D. yes, passive immunity stimulates T cells

B. no, passive immunity does not have memory

What is one reason why active immunity is more advantageous than passive immunity?

A. passive immunity is always better

B. active immunity leads to the development of immunological memory

C. active immunity is fast-actin

D. active immunity is slower and less likely to produce mistakes

B. active immunity leads to the development of immunological memory

Normal skin flora are able to survive on the surface of skin because of their tolerance to ___

A. salt

B. sebum

C. lower pH than inside the body

D. All of the above

D. All of the above

Why is skin an effective barrier to microbes?

A. the outer lawyers are dead and covered in salt

B. organisms cannot survive on the skin surface

C. the outer layer is covered in blood vessels

D. melanin is cytotoxic

A. the outer lawyers are dead and covered in salt

What is the most common species of Staphylococcus found on the skin?

A. S. epidermidis

B. S. aureus

C. S. hominis

D. S. capitis

A. S. epidermidis

How do people become infected with Listeria monocytogenes?

A. ingesting contaminated food or drink

B. inhaling aerosolized bacteria

C. through a cut or abrasion

D. contact with an infected person

A. ingesting contaminated food or drink

How are prions infectious?

A. they refold normal prion proteins in the cell into the abnormal form of the prion protein

B. they inject their DNA into the nucleus

C. they kill cells

D. the mechanism is unknown

A. they refold normal prion proteins in the cell into the abnormal form of the prion protein

Which of the following best defines axenic?

A. transferred from animal to human

B. free of microbes

C. full of microbes

D. transferred from human to animal

B. free of microbes