Microbiology Exam 4. Ch. 23

D. produces suboptimal temperatures for the microbe

How does a moderate fever slow bacterial growth? A. produces prostaglandin E2 B. increases iron availability C. produces pyrogens, which opsonize microbes D. produces suboptimal temperatures for the microbe

C. help protect cells from viral infection.

Type I interferons A. reduce cellular levels of double-stranded RNA endonucleases. B. are not host species specific (e.g., rabbit interferon will work in mice). C. help protect cells from viral infection. D. are produced in response to extracellular pathogens.

B. The classical pathway

Which complement cascade pathway depends on the production of antibodies? A. The CD47 pathway B. The classical pathway C. The alternative pathway D. The lectin pathway

D. autophagy

An individual is infected with Mycobacterium tuberculosis. The bacteria infect macrophages in the lungs, where it survives and reproduces intracellularly. What is the most likely mechanism the infected macrophages will use to combat the invading bacteria? A. opsonization B. extravasation C. degranulation D. autophagy

A. Without the capsule, opsonization of the mutant will not be required for host macrophages to ingest the microbe, making it less pathogenic.

A Streptococcus pneumoniae mutant does not produce a capsule. What will be the most likely result of this mutation if the bacteria infect a host? A. Without the capsule, opsonization of the mutant will not be required for host macrophages to ingest the microbe, making it less pathogenic. B. The loss of the capsule will protect the bacteria from the oxidative burst in the phagolysosome and allow them to survive within phagocytes. C. Without the capsule, the bacteria are more likely to cause septicemia (an infection of the blood) because they will enter the blood by extravasation more easily than encapsulated bacteria. D. Without the capsule, the bacteria no longer produce MAMPs and so will escape detection by the host's immune system.

B. innate and adaptive branches of immunity

Below are two statements about the immune system: Macrophages ingest and degrade microbes and present the microbial antigens to other immune system cells. Antibodies on the surface of virally infected host cells activate natural killer (NK) cells. These two statements are examples of the connections between which of the following? A. phagocytosis and inflammation B. innate and adaptive branches of immunity C. neutrophil extracellular traps (NETs) and the disease lupus D. primary and secondary lymphoid tissues

B. stimulating the release of cytokines by macrophages

Bradykinin plays several roles in inflammation. Which of the following is not a function of bradykinin in inflammation? A. triggering the release of histamine from mast cells B. stimulating the release of cytokines by macrophages C. causing capillary cells to release prostaglandins D. loosening the junctions between endothelial cells

C. promote phagocytosis.

Complement protein factor C3b is an opsonin, which means it can A. trigger degranulation of cells. B. stimulate chemotaxis of immune cells. C. promote phagocytosis. D. initiate membrane attack complex formation.

Skin: Lang. Cell, Sebum GI tract: M cells. Lungs: Alveolar, Cystic fibrosis transmembrane conductance regulator , Mucociliary escalator.

Components of the physical barriers that protect the skin, gastrointestinal tract, and lungs are given below. Drag each component to the organ that it protects. Skins: Gastrointestinal Tract: Lungs: Langerhans cells, M cells, Sebum, Alveolar marcrophages, Cystic fibrosis transmembrane conductance regulator, Mucociliary escalator

Round, purple, small chunks inside.

Describe what Neutrophile looks like.

D. increased permeability of endothelial cell junctions.

Extravasation of immune cells depends on A. increased vasoconstriction. B. antibody production by B cells. C. down regulation of selectin proteins on endothelial cells. D. increased permeability of endothelial cell junctions.

C. It destroys the proton motive force required for energy production.

How does the alternative complement pathway kill the invading microbial cell? A. It causes the oxidation of the microbe's membranes by producing superoxide ion. B. It enhances the phagocytosis of the microbes by host cells. C. It destroys the proton motive force required for energy production. D. It stimulates the production of neutrophil extracellular traps (NETs), which trap the microbes and kill them with antimicrobial compounds.

C. blood

In which of the following body sites would the mere presence of microbes indicate an infection? A. lungs B. stomach C. blood D. bladder E. skin

D. nonadaptive

Innate immunity is also called __________ immunity. A. antibody-mediated B. antigen-mediated C. adaptive D. nonadaptive

C. Type I interferes with viral replication, while type II activates white blood cells.

Interferons are cytokines produced by host cells in response to intracellular infection. There are two types of interferons, type I and type II. Which of the following is a difference between these two types? A. Type I binds to extracellular pathogens, while type II binds to intracellular pathogens. B. Type I is part of innate, nonspecific immunity, while type II is part of adaptive, specific immunity. C. Type I interferes with viral replication, while type II activates white blood cells. D. Type I includes interferon-alpha and interferon-beta, while type II includes interferon-omega.

compromised, opportunistic

Michael has Acquired Immunodeficiency Syndrome (AIDS) caused by the Human Immunodeficiency Virus (HIV). The damage that the virus has done to Michael's immune system has made him susceptible to a yeast infection of his respiratory tract, called Candidiasis. Individuals with a healthy immune system do not develop this yeast infection. Michael is a(n) _____ and the yeast that causes Candidiasis is a(n) _____.

D. high; low

Microbes that colonize the skin need to be resistant to __________ salt and __________ pH. A. low; high B. high; high C. low; low D. high; low

C. Phagocytosis

Microbial species of the microbiota may interfere with colonization of pathogens by all EXCEPT which of the following mechanisms? A. Competition for food sources B. Competition for attachment receptors on host cells C. Phagocytosis D. Through the synthesis of antimicrobial compounds

B. moves the temperature outside the pathogens' optimal range.

Moderate fever can actually be beneficial because it A. increases inflammation. B. moves the temperature outside the pathogens' optimal range. C. increases iron availability to pathogens. D. causes enzymatic denaturation.

E. bladder - presence of bile salts

Organs have varied mechanisms for limiting the amount and types of colonizing microbiota. In the choices below, organs are matched with one of their microbiota-limiting mechanisms. Which organ and mechanism are mismatched? A. skin - presence of dry, high-salt environments B. intestine - secretion of lectins that separate the microbiome from the host mucosal cells C. eye - constant washing action with antimicrobial factors such as lysozyme D. lungs - action of the mucociliary escalator E. bladder - presence of bile salts

Neutrophiles: phagocytic, lattice-works of DNA, majority of leukocytes Basophiles: contain IgE, similar to mast cells.

Polymorphonuclear leukocytes (PMNs) are involved in innate immunity and include neutrophils and basophils. Sort the following descriptions as they apply to either of these two PMNs. Neutrophils: Basophiles: are phagocytic, produce lattice-work of DNA that trap pathogens, are the majority of leukocytes in blood, contains IgE receptors associated with allergies, are similar to mast cell.

C. the donor's healthy microbiome outcompetes the C. difficile and restores balance to the gut microbiome in the patient.

Pseudomembranous enterocolitis is caused by an overgrowth of the bacteria Clostridioides difficile. This overgrowth can be caused by antibiotic therapy in which sensitive members of the microbiome are killed or inhibited by the antibiotic drug, but the resistant C. difficile is not. Because the C. difficile infection is resistant to many antibiotics, it is hard to treat. Cases of pseudomembranous enterocolitis have been cured with fecal transplants in which the gut microbiome of a donor healthy person is transferred into the patient. Fecal transplants work to cure this resistant infection because A. inflammation that combats the C. difficile infection is promoted in the gut of the patient by the donor's microbiome. B. C. difficile is sensitized to antibiotic drugs by factors in the donor's microbiome. C. the donor's healthy microbiome outcompetes the C. difficile and restores balance to the gut microbiome in the patient. D. a different strain of C. difficile from the healthy donor replaces the patient's strain.

D. increase the temperature set point.

Pyrogens indirectly cause the hypothalamus to A. alter the temperature set point erratically and frequently. B. decrease the temperature set point. C. keep the temperature set point the same. D. increase the temperature set point.

C and D.

Some cells of the innate immune system present antigens to T cells of the adaptive immune system. Cells that can present the antigens are logically called antigen-presenting cells (APCs) and include which of the following? Choose two: A. neutrophils B. natural killer cells C. dendritic cells D. macrophages E. eosinophils F. basophils

C. warmth - increased production of pyrogens

The five classic signs of localized inflammation are redness, warmth, pain, swelling, and altered function at the affected site. Altered function is caused when swelling interferes with the movement and function of the inflamed area. The other signs are matched with their causes below. Which sign and cause are mismatched? A. redness - increased blood flow to the site B. swelling - increased vascular permeability C. warmth - increased production of pyrogens D. pain - increased production of prostaglandin

C, E, and G.

The gut microbiome benefits the host in many ways. One benefit of the gut microbiome is that it helps to prevent infection by pathogenic microbes. To directly compete with and inhibit the growth of pathogenic microbes, members of the gut microbiome do which of the following? Choose three: A. synthesize vitamins B. degrade mucin C. occupy attachment receptors D. compete for mates E. secrete substances that inhibit the growth of pathogens F. degrade complex carbohydrates G. compete for nutrients

B. endothelial VCAM - mast cells

The inflammatory response depends on the interaction of many inflammatory molecules and cellular proteins. Which of the following pairs of molecules or cells does not interact? A. endothelial selectin - neutrophil surface carbohydrates B. endothelial VCAM - mast cells C. neutrophil integrins - endothelial ICAM D. endothelial prostaglandins - nerve cells

B, D, and E.

The microbiome has both associated benefits and risks. What are some of the risks associated with the oral microbiome? Choose three: A. urinary tract infections B. subacute bacterial endocarditis C. gastric ulcers D. tooth decay E. bacteremia

A and E.

Which of the following activates a natural killer (NK) cell to kill a host cell? Choose two: A. absence of MHC I on the host cell B. presence of MHC I on the NK cell C. absence of antibodies on the NK cell D. absence of MHC I on the NK cell E. presence of antibodies on the host cell F. presence of MHC I on the host cell G. absence of antibodies on the host cell H. presence of antibodies on the NK cell

A. M cells

Which of the following cell types is present in gut-associated lymphoid tissue (GALT) and takes up microbes, releasing them into pockets containing macrophages? A. M cells B. Paneth cells C. Langerhans cells D. alveolar macrophages

A. A Gram-negative bacterium

Which of the following cells is most likely to be killed via the alternative complement pathway? A. A Gram-negative bacterium B. A virally infected host cell C. A Gram-positive bacterium D. A parasitic worm

B. Defensins

Which of the following chemical defenses are produced by host cells to destroy invaders' membranes? A. Acidic pH B. Defensins C. Superoxides D. Lysozyme

B. alternative complement pathway

Which of the following complement pathways is activated by lipopolysaccharide? A. opsonin pathway B. alternative complement pathway C. classical complement pathway D. lectin pathway

C. type I interferons

Which of the following host cell products prevents viral infections by inhibiting viral replication? A. Toll-like receptors B. type II interferons C. type I interferons D. NOD-like receptors

C. Tightly linked epithelial cells

Which of the following is a physical barrier to microbial infection in innate immunity? A. Superoxide radicals B. Antimicrobial peptides C. Tightly linked epithelial cells D. Acidic pH

D. microbe-associated molecular patterns

Which of the following is not an innate chemical defense used by the host to protect itself against infection? A. acidic pH B. alpha defensins C. lysozyme D. microbe-associated molecular patterns

D. Its two branches, innate and adaptive, are isolated from each other.

Which of the following is not true of the immune system? A. It is capable of responding to almost any foreign molecule. B. Its cells differentiate between self and nonself. C. It includes organs, cells, and cell products. D. Its two branches, innate and adaptive, are isolated from each other.

B. They are the cells most likely to first encounter an invading pathogen.

Which of the following is true of macrophages? A. They participate in the innate immune response but not in the adaptive immune response. B. They are the cells most likely to first encounter an invading pathogen. C. They produce antibodies in response to antigens presented by antigen-presenting cells. D. They are unable to perform phagocytosis.

B. It can help aid digestion and absorption of nutrients.

Which of the following is true of the normal intestinal microbiota? A. The normal microbiota contains only bacterial species. B. It can help aid digestion and absorption of nutrients. C. The microbes that are present will not harm the host if they colonize a different tissue. D. There are up to two dozen different species present.

B. Blood

Which of the following locations is LEAST likely to harbor commensal microbes? A. Skin B. Blood C. Mouth D. Vagina

C. Macrophages are involved only in innate immunity.

Which of the following statements about macrophages is false? A. Macrophages present microbial peptide antigens on major histocompatibility complexes. B. Macrophages are phagocytic. C. Macrophages are involved only in innate immunity. D. Macrophages differentiate only from monocytes.

B. Toll-like receptors

Which receptors on host cells participating in innate immunity recognize bacterial proteins? A. CD47 receptors B. Toll-like receptors C. Fc receptors D. MHC receptors