Chapter 15

Mucus-secreting membranes are found in
A. The urinary system
B. The digestive cavity
C. The respiratory cavity
D. All of the above

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.

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 is inhospitable to most microbes, but some normal microbiota are present.
C. Salt, defensins, enzymes, and a low pH make the skin inhospitable for all mcirobes.

Which of these statements accurately describes pathocytosis?
A. Pathogens are killed in phagolysosomes by acid and oxidative radicals
B. Phagocytosis is inhibited by opsonins
C. The purpose of phagocytosis is to transport nutrients in blood

The type of interferon present late in an infection is:
A. Alpha interferon
B. Beta interferon
C. Gamma interferon
D. Delta interferon

Which of the following is NOT targeted by a Toll-like receptor?
A. Lipid A
B. Eukaryotic flagellar protein
C. Single stranded RNA
D. Lipoteichoic acid

Which complement fragement is inflammatory?
A. C3a
B. C5a
C. C4a
D. All of the above

_____ of complement activation acts in conjuction with the action of antibodies.
A. The classical pathway
B. The alternative pathway
C. The lectin pathway
D. The attack pathway

_____ is the inflammatory mediator released by mast cells
A. Complement
B. Bradykinin
C. Histamine
D. Interferon

The (epithelial or goblet or mucous) cells in the tracheal mucous membrane produce mucus.

Sweat can cause damage to bacteria because it contains salt and lysozyme.
(True/False)

The leukocytes called natural killer lymphocytes:
A) respond to the coating of a pathogen by complement.
B) are specialists in killing bacteria.
C) are nonspecific leukocytes that secrete toxins onto the surface of virus-infected cells.
D) release prostaglandins and leukotrienes in response to microbes.
E) increase in allergies and helminth infection.

Which of the following are macrophage functions?
A) production of NETs
B) phagocytosis of pathogens and debris
C) phagocytosis of pathogens and production of NETs
D) phagocytosis of pathogens and secretion of alpha interferons and leukotrienes
E) release of alpha interferon

Which of the following are among the activities of neutrophils?
A) formation of neutrophil extracellular traps and release of histamines
B) release of histamines
C) formation of neutrophil extracellular traps
D) enzyme production that leads to the formation of nitric oxide
E) formation of neutrophil extracellular traps and production of nitric oxide

Which of the following proteins are part of the first line of defense against microbial invasion?
A) interferons
B) C3 and C5
C) dermicidins
D) NOD proteins
E) TLRs

Which cell becomes a macrophage when leaving the bloodstream?
A) erythrocyte
B) monocyte
C) eosinophil
D) basophil
E) neutrophil

Mannose sugar occurs on the surface of some bacteria and fungi and can trigger the:
A) release of NETs by neutrophils.
B) classical pathway of complement activation.
C) release of histamines by basophils.
D) lectin pathway of complement activation.
E) release of cytotoxins by NK cells

The components of the second line of defense against microbes may be characterized as:
A) both passive barriers and detecting specific pathogen features.
B) responders to invasion
C) mechanisms to strengthen the first line of defense.
D) detecting the unique features of specific pathogens.
E) passive barriers

Fever is beneficial during viral infection because the higher temperature:
A) increases sweating and consequently the barrier effect.
B) inactivates interferons.
C) increases vasodilation, contributing to inflammation.
D) prevents viral infection of fibroblasts.
E) increases the effectiveness of interferons.

Choose the most common portal of entry for most pathogens:
A) the urinary tract
B) parenteral route (cuts, wounds abrasions, bites, etc.)
C) the respiratory tract
D) the skin
E) the conjunctiva of the eyes

If SARS-CoV-2, the virus responsible for Covid-19, continues to spread and infect us without causing outbreaks of severe disease (due to immunization campaigns and increased immunity of the population to the pathogen) - at that point, we would say that Covid-19 is an (endemic/epidemic/sporadic) disease.
A) sporadic
B) endemic
C) epidemic

Many people infected with tuberculosis do not have symptoms of Tb disease. In these cases, the pathogen remains inactive within the body and it may become active at a later time. Inactive Tb is an example of:
A) opportunistic disease
B) latent disease
C) subacute disease
D) acute disease
E) chronic disease

Apply the definitions of disease signs and symptoms to determine whether the following statement is true or false: "Fever, redness, and swelling are signs - not symptoms - of disease".
True/False

In which example could a typically resident microbe become an opportunistic pathogen?
A) growth of microorganisms on the excreted cellular wastes and dead cells in the large intestine
B) Resident flora grow on the surface of intact skin
C) presence of Entamoeba in the lumen of the colon
D) Lactobacilli grow on the surface of teeth
E) E. coli enters the urinary tract

Many pathogenic bacteria can secrete exotoxins which can harm the host. A key way that the body protects itself from exotoxins is through protective molecules called:
A) antibodies
B) capsules
C) kinases
D) protein F
E) hyaluronidases

In early spring 2009, the CDC reported several dozen cases of novel H1N1 influenza ("swine flu") in the United States. By the end of the year millions of people had been infected. The pattern of novel H1N1 cases in the United States represents a(n) ________ disease.
A) epidemic
B) sporadic
C) pandemic
D) opportunistic
E) endemic

The incidence of tuberculosis in the year 2000 in the United States was 12.43/100,000 cases. This means:
A) 12.43 of every 100,000 people died of tuberculosis in the United States in the year 2000.
B) there were 12.43 tubercle bacilli per 100,000 microbes in the United States in the year 2000.
C) 12.43 of every 100,000 cases of tuberculosis were treated in the United States in the year 2000.
D) there were 12.43 new cases of tuberculosis for every 100,000 people in the United States in the year 2000.
E) 12.43 of every 100,000 people in the United States had tuberculosis in the year 2000.

An American cruise ship identifies a passenger as positive for SARS CoV-2, although the passenger had never had Covid-19 and did not have any signs or symptoms of disease. Which of the following is the most accurate description of the passenger in this scenario?
A) reservoir
B) human carrier
C) a reservoir but not a carrier
D) both a human carrier and a reservoir
E) contact carrier

Which of the following virulence factors allows pathogens to evade phagocytosis?
A) hyaluronidase
B) capsules
C) adhesins
D) ligands
E) kinases

Amensalism is best described as a(n):
A) relationship in which a microorganism causes disease.
B) relationship between two organisms where neither benefits or is harmed.
C) relationship between two organisms where one is harmed and the other neither benefits or is harmed.
D) unsuccessful microbial invasion due to the presence of preexisting microbes.
E) relationship between two organisms where both members benefit.

Droplet transmission is a form of vehicle transmission.
True/False

Cutibacterium acnes is a bacterium that is commonly present on human hair follicles and sebaceous glands where it rarely causes disease. Which type of symbiosis does this represent? (you may assume there is no benefit to humans from the symbiosis)

A woman dies after sharing a contaminated needle, resulting in (contact/vehicle/vector) transmission.

The condition known as microbial antagonism may be defined as:
A) an unsuccessful microbial invasion due to the presence of pre-existing microbes
B) microorganisms that remain with a person throughout life.
C) a relationship between two organisms where only one member benefits.
D) a relationship between two organisms where one member harms the other.
E) a relationship between two organisms where both members benefit.

Infectious diseases can be classified on the basis of:
A) means of transmission.
B) type of microbe that causes the disease.
C) disease severity and duration, organ system affected or type of microbe.
D) severity and duration of the disease.
E) organs or organ systems affected by the disease.

A patient developed a blood infection after a dental procedure which resulted in bleeding gums. The patient has:
A) a subclinical infection
B) a healthcare-associated infection (HAI).
C) a zoonotic infection
D) an exogenous infection
E) a superinfection

Aerosols may be involved in ________ transmission of pathogens.
A) direct
B) droplet
C) fecal-oral
D) waterborne
E) vector

People in the incubation stage of a disease may be a reservoir of the agent.
True/False

Which of the following cells increase in number during an infection with parasitic worms?
A) neutrophils
B) basophils
C) lymphocytes
D) macrophages
E) eosinophils

Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?
A) the mucus is a physical trap that contains a variety of antimicrobial chemicals.
B) both the mucus and the outer layer of cells are shed frequently.
C) the mucus secreted by the mucous membrane physically traps microbes.
D) the mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
E) the mucus contains a variety of antimicrobial chemicals and molecules.

Antimicrobial peptides called ________ are secreted in sweat and damage bacteria and fungi.
A) cytokines
B) TLRs
C) complement factors
D) dermicidins
E) antibodies

The complement cascade and its by-products contribute to:
A) triggering release of interferons.
B) triggering inflammation and release of interferons.
C) attracting phagocytes to sites of infection.
D) triggering inflammation.
E) both triggering inflammation and attracting phagocytes to sites of infection.

Cells of the second line of defense called ________ recognize and kill virus-infected cells.
A) dendritic cells
B) macrophages
C) eosinophils
D) basophils
E) natural killer (NK) cells

Which of the following is NOT a stage of phagocytosis?
A) adhesion
B) elimination
C) fusion
D) secretion of cytotoxins
E) chemotaxis

Which of the following statements regarding phagocyte recognition of pathogens is true?
A) MACs on the surface of microbes are detected by NOD proteins.
B) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.
C) Lectins on the surface of microbes are bound by chemokine receptors.
D) TLRs on the surface of microbes trigger the accumulation of opsonins.
E) NOD proteins on the surface of microbes are detected by TLRs.

Alpha and beta interferons:
A) are produced by infected fibroblasts and macrophages.
B) produce no adverse effects in the body.
C) protect the cells that secrete them from being invaded by a virus.
D) help protect virus-infected cells from the effects of the pathogen.
E) produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent the attachment of pathogenic viruses.

Receptors known as ________ are receptors for microbial molecules in the cytoplasm.
A) NETs
B) MACs
C) lectins
D) TLRs
E) NOD proteins

The alternative pathway of complement cascade activation begins with ________ binding to the surface of a microbe.
A) C3b
B) C5b
C) C5a
D) C1
E) factor B

Which of the following substances contributes to the edema associated with inflammation?
A) interferon
B) histamine
C) both leukotrienes and histamine
D) defensin
E) leukotrienes

Which of the following proteins of the complement cascade triggers inflammation?
A) factor B
B) C2b
C) C4a
D) MAC
E) C3b

Opsonization is:
A) the sticking of monocytes to the wall of the blood vessels at the site of infection.
B) nonspecific leukocyte secretion of toxins onto the surface of virally infected cells.
C) phagocyte receptors detecting PAMPs.
D) damage resulting in cell lysis.
E) the coating of a pathogen by complement to facilitate phagocytosis.

A person produces a mutated C3 protein resulting in C3b failing to stick, but enzymatic function is not affected. Complement activation in this individual would result in which of the following?
A) Phagocytosis would be facilitated but chemotaxis by phagocytes would be reduced.
B) MACs would form but inflammation would not occur.
C) Phagocytes would not be attracted to the site of infection.
D) Phagocytes would be attracted to the site of infection but phagocytosis would be impaired.
E) MACs would not form.

Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead and dying tissue cells, leukocytes, and pathogens?
A) a pustule
B) an abscess
C) a tumor
D) a boil
E) a pimple

How does aspirin act to decrease the symptoms of inflammation?
A) it interferes with the action of interferons.
B) it prevents complement activation.
C) it acts as an anti-prostaglandin.
D) it is an anti-toxoid for most microbial toxins.
E) it blocks the release of histamine

Microbial molecules detected by phagocytes are called:
A) NODs
B) prostaglandins
C) PAMPs
D) TLRs
E) leukotrienes

TLRs are:
A) phagocyte receptors that detect PAMPs.
B) the coatings of pathogens by complement.
C) molecules that damage cells, resulting in cell lysis.
D) present in intact skin, sebum, tears, etc.
E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

Interferons alpha and beta are effective against viruses.
True/False

Innate immune defenses are nonspecific defenses against microbial invaders.
True/False

This toxin is responsible for the toxicity of Gram-negative bacteria:
A) hemolysin
B) neurotoxin
C) Lipid A
D) collagenase
E) coagulase