Mastering Micro: Innate Immunity

Which of the following is NOT a step that ultimately leads to antibody production? A) Activation of cytotoxic T cells by helper T cells B) Differentiation of plasma cells C) Activation of helper T cells by dendritic cells D) Immature B cells conducting surveillance for foreign epitopes

A) Activation of cytotoxic T cells by helper T cells

Each of the different activation pathways for complement has advantages and disadvantages compared to the other two pathways. Which of the following correctly lists an advantage and a disadvantage of classical activation in response to a new microbial intruder? A) Advantage: very specific. Disadvantage: slow to induce complement. B) Advantage: fast to induce complement. Disadvantage: NOT very specific. C) Advantage: fast to induce complement. Disadvantage: very specific. D) Advantage: very specific. Disadvantage: fast to induce complement.

A) Advantage: very specific. Disadvantage: slow to induce complement.

Which pair of molecules do NOT directly interact with one another? A) BCR and TCR B) CD8 and MHC-I C) BCR and epitope D) CD4 and MHC-II

A) BCR and TCR

Which of the following statements about the classical pathway of complement activation is FALSE? A) C3 is not involved in the classical pathway. B) C1 is the first protein activated in the classical pathway. C) C3b causes opsonization. D) Cleaved fragments of some of the proteins act to increase inflammation. E) The C1 protein complex is initiated by antigen-antibody complexes.

A) C3 is not involved in the classical pathway.

n the classical pathway, which of the following directly activates cellular responses? A) C3a, C5a, and C5bC6C7 B) C3b C) C5bC6C7 D) C4aC2bC3b E) C3a and C5a F) C2aC4b

A) C3a, C5a, and C5bC6C7

What complement result involves the use of phagocytes? A) Chemotaxis and opsonization B) Opsonization C) Cytolysis D) Chemotaxis

A) Chemotaxis and opsonization

A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count? A) Clonal selection of B cells B) Apoptosis of infected host cells C) Clonal expansion and antibody production D) Activation of cytotoxic T cells

A) Clonal selection of B cells

If a person could not form C2, which result of complement would be affected? A) Cytolysis, chemotaxis, inflammation, and opsonization B) Cytolysis C) Chemotaxis and inflammation D) Opsonization

A) Cytolysis, chemotaxis, inflammation, and opsonization

Which of the following phagocytic processes occurs last in the sequence? A) Exocytosis B) Chemotaxis of the phagocyte to the site of infection C) Formation of the phagolysosome D) Adherence

A) Exocytosis

What is the role of helper T cells in the adaptive immune response? A) Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells. B) Helper T cells phagocytize bacteria and viruses. C) Helper T cells produce and secrete antibodies. D) Helper T cells directly kill infected host cells.

A) Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.

How is phagocytosis in the immune system different from protozoan phagocytosis? A) Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection. B) Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells. C) There is no difference between the two.

A) Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.

All of the following pertain to fever EXCEPT that it A) accelerates microbial growth by increasing iron absorption from the digestive tract. B) is caused by interleukin-1 and TNF-alpha coming into contact with the hypothalamus. C) stimulates T lymphocyte activity. D) intensifies the effect of antiviral interferons. E) can be initiated by specific types of pathogens.

A) accelerates microbial growth by increasing iron absorption from the digestive tract.

Which of the following is found normally in serum? A) complement B) interferon C) TLRs D) leukocytosis-promoting factor E) histamine

A) complement

Which of the following is involved in resistance to parasitic helminths? A) eosinophils B) basophils C) neutrophils D) monocytes E) lymphocytes

A) eosinophils

Each of the following provides protection from phagocytic digestion EXCEPT A) formation of phagolysosomes. B) M protein. C) capsules. D) leukocidins. E) biofilms.

A) formation of phagolysosomes.

Which of the following is an effect of opsonization? A) increased adherence of phagocytes to microorganisms B) increased diapedesis of phagocytes C) inflammation D) increased margination of phagocytes E) cytolysis

A) increased adherence of phagocytes to microorganisms

Julie is preparing vegetables for dinner and accidentally cuts her finger. She washes it with soap and water before covering it with a bandage. A short while later, Julie notices that her finger is red, swollen, warm to the touch, and very painful. Which of the following describes the process going on in Julie's finger? A) inflammation B) fever C) phagocytosis D) complement

A) inflammation

Which of the following is an event that ultimately results in activation of complement C3 by splitting it into C3a and C3b? A) interaction of mannose-binding lectin with mannose molecules on a bacterium B) binding of factors B, D, and P to antibodies on bacteria C) binding of C2 to antigen-antibody complexes D) linkage of C2b with C4a

A) interaction of mannose-binding lectin with mannose molecules on a bacterium

Each of the following is an effect of complement activation EXCEPT A) interference with viral replication. B) opsonization. C) increased blood vessel permeability. D) increased phagocytic activity. E) bacterial cell lysis.

A) interference with viral replication.

All of the following increase blood vessel permeability EXCEPT A) lysozymes. B) prostaglandins. C) leukotrienes. D) histamine. E) Kinins

A) lysozymes.

Neutrophils with defective lysosomes are unable to A) produce toxic oxygen products. B) undergo chemotaxis. C) attach to microorganisms and other foreign material. D) engulf microorganisms and other foreign material. E) migrate.

A) produce toxic oxygen products.

All of the following are effects of histamine EXCEPT A) production of antibodies. B) removal of an injurious agent. C) isolation of an injurious agent. D) destruction of an injurious agent. E) repair of damaged tissue.

A) production of antibodies.

Correctly order the steps involved cellular immunity: 1. The Tc recognizes the infected host cell 2. The Tc interacts with epitope presented by MHC-I on the dendritic cell 3. The Tc secretes perforin and granzyme, causing apoptosis 4. The helper T cell activates the Tc cell A) 4,2,1,3 B) 2,4,1,3 C) 2,1,3,4 D) 1,2,4,3

B) 2,4,1,3

Which of the complement pathways employs properdin? A) Classical pathway B) Alternative pathway C) Lectin pathway D) Alternative and lectin pathways all employ properdin. E) Classical, alternative, and lectin pathways all employ properdin. F) The classical and alternative pathways both require properdin.

B) Alternative pathway

A microbe has the ability to inhibit complement activation of inflammation, but it cannot inhibit complement activation of opsonization and cytolysis. Therefore, the microbe has produced inhibitors of which complement protein(s)? A) C3a B) C3a and C5a C) C3b and C5b D) C5a

B) C3a and C5a

Which microorganism requires the low pH inside a phagolysosome in order to reproduce? A) Streptococcus pyogenes B) Coxiella burnetii C) Haemophilus influenzae D) Streptococcus pneumoniae

B) Coxiella burnetii

What does the plasma membrane of a phagocyte attach to on a microorganism? A) Phagosomes B) Glycoproteins C) Pseudopods D) Lysosomes

B) Glycoproteins

Which of the following statements about innate immunity is true? A) The innate immune response does not have a mechanism for detecting invading microorganisms. It is activated only in response to tissue damage or a signal from an infected cell. B) Innate immunity is present at birth. C) Innate immunity involves specific recognition of microorganisms via a memory response. D) It involves the activity of B and T cells.

B) Innate immunity is present at birth.

What cellular macromolecules make up the complement pathway? A) Nucleic acids B) Proteins C) Carbohydrates D) Lipids

B) Proteins

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? A) Recognition of infected host cell using its TCR B) Recognition of infected host cell using its CD4 glycoprotein C) Secretion of granzyme D) Secretion of perforin

B) Recognition of infected host cell using its CD4 glycoprotein

Which of the following microorganisms use M protein to avoid destruction of a phagocyte? A) Coxiella burnetii B) Streptococcus pyogenes C) Haemophilus influenzae D) Streptococcus pneumoniae

B) Streptococcus pyogenes

Which of the following defense systems would be involved in eliminating virally-infected cells? A) Complement system B) T lymphocytes C) Phagocytosis D) Humoral immunity

B) T lymphocytes

What is a phagolysosome? A) A vesicle containing only an engulfed invading microorganism. B) The structure that results from the fusion of a phagosome and a lysosome. C) A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. D) A vesicle containing only digestive enzymes and other antimicrobial compounds.

B) The structure that results from the fusion of a phagosome and a lysosome.

How is Streptococcus pneumoniae able to avoid destruction by a phagocyte? A) They prevent the fusion of the lysosome and phagosome. B) Their capsules make them "slippery" to phagocytes. C) They cause the lysosomes to empty their contents into the phagocyte, killing it.

B) Their capsules make them "slippery" to phagocytes.

What is the role of opsonins? A) They aid in the formation of the phagolysosome. B) They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader. C) They attract phagocytes to the location of infection. D) They are present on the surface of phagocytes.

B) They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.

If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be A) a cytotoxic T cell. B) a phagocyte. C) an antibody-producing cell.

B) a phagocyte.

The classical pathway of complement activation begins with binding of __________. A) lectin B) an antibody C) C3 D) complement proteins

B) an antibody

The classical pathway for complement activation is initiated by A) lipid-carbohydrate complexes and C3. B) antigen-antibody reactions. C) C5-C9. D) factors released from damaged tissues. E) factors released from phagocytes.

B) antigen-antibody reactions.

Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe? A) deficiency of C8 B) deficiency of C3 C) deficiency of C6 D) deficiency of C5 E) deficiency of C7

B) deficiency of C3

The antimicrobial effects of AMPs include all of the following EXCEPT A) inhibition of cell wall synthesis. B) inhibition of phagocytosis. C) lysis of bacterial cells. D) destruction of nucleic acids. E) pore formation in bacterial membranes.

B) inhibition of phagocytosis.

Which group contains ONLY innate physical defenses? A) B lymphocytes, blood, macrophages B) intact skin, tears, ciliary escalator C) lysozymes, stomach pH, sweat D) mucus, sebum, saliva

B) intact skin, tears, ciliary escalator

Phagocytes utilize all of the following to optimize interaction with (getting to and getting hold of) microorganisms EXCEPT A) chemotaxis. B) lysozyme. C) complement. D) trapping a bacterium against a rough surface. E) opsonization.

B) lysozyme.

As mentioned previously, the second line of defense is activated when the first line of defense fails. In Part A, you identified one of these defenses as inflammation, which occurs when the body responds to a foreign antigen and increases fluid accumulation in a specific area. An added benefit of this excess fluid is that it also brings immune cells to the area to aid clearance of foreign antigens. In Julie's situation, that added fluid would bring immune cells to prevent any microbial infections that could be caused if microbes were introduced when she cut her finger. Which of the following cell types is NOT part of the second line of defense? A) mast cells B) plasma cells C) eosinophils D) basophils

B) plasma cells

Antibodies from cellular immune responses are used in A) both the classical and alternative pathways. B) the classical pathway. C) the alternative pathway. D) the lectin pathway.

B) the classical pathway.

A differential cell count is used to determine each of the following EXCEPT A) leukocytosis. B) the number of red blood cells. C) the numbers of each type of white blood cell. D) leukopenia. E) the total number of white blood cells.

B) the number of red blood cells

The function of the "ciliary escalator" is to A) remove microorganisms from the gastrointestinal tract. B) trap inhaled dust and microorganisms in mucus and propel it away from the lower respiratory tract. C) propel inhaled dust and microorganisms toward the mouth, away from the lower respiratory tract. D) trap microorganisms in mucus in the upper respiratory tract. E) remove microorganisms from the lower respiratory tract.

B) trap inhaled dust and microorganisms in mucus and propel it away from the lower respiratory tract.

Place the following steps of phagocytosis in the order that they occur: 1. Endosome fuses with lysozome 2. Dendritic cell engulfs Rhinovirus 3. Epitopes are attached to MHC-II 4. Digestion of the Rhinovirus 5. MHC-II plus the attached epitope move to the outside of the dendritic cell A) 1,2,4,3,5 B) 2,1,3,4,5 C) 2,1,4,3,5 D) 2,4,1,3,5

C) 2,1,4,3,5

Which statement regarding the lymphatic system is true? A) Lymph nodes are sites of activation of neutrophils, which destroy microbes. B) The pancreas contains lymphocytes and macrophages that monitor the blood for microbes. C) Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces. D) The thymus serves as the site for activation of B cells.

C) Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.

If a person lacked the ability to form C5, what direct result of complement could still occur? A) Cytolysis B) Chemotaxis C) Opsonization

C) Opsonization

Where are the complement proteins found in the body? A) In every cell B) The liver C) The blood serum D) The thymus E) The spleen

C) The blood serum

Which of the complement pathways was discovered first? A) The lectin pathway B) The alternative pathway C) The classical pathway

C) The classical pathway

Margination refers to A) the movement of phagocytes through walls of blood vessels. B) dilation of blood vessels. C) adherence of phagocytes to the lining of blood vessels. D) the adherence of phagocytes to microorganisms. E) the chemotactic response of phagocytes.

C) adherence of phagocytes to the lining of blood vessels.

Which of the following is mismatched? A) pus tissue debris and dead phagocytes in a white or yellow fluid B) scab dried blood clot over injured tissue C) chemotaxis chemical degradation inside a phagolysosome D) diapedesis movement of leukocytes between capillary walls cells out of blood and into tissue E) abcess a cavity created by tissue damage and filled with pus

C) chemotaxis chemical degradation inside a phagolysosome

All of the following are effects of histamine EXCEPT A) redness. B) pain. C) fever. D) vasodilation. E) swelling.

C) fever.

Which non-specific defense mechanism is mismatched with its associated body structure or body fluid? A) very acidic pH stomach B) keratin and tightly packed cells skin C) mucociliary escalator intestines D) lysozyme tears and saliva E) cerumen and sebum ear

C) mucociliary escalator intestines

Phagocytosis is defined as A) the uptake of liquid material by a eukaryotic cell. B) the feeding of protozoans. C) the ingestion of solid material by a eukaryotic cell. D) cells of the immune system that ingest pathogens.

C) the ingestion of solid material by a eukaryotic cell.

TLRs attach to all of the following EXCEPT A) LPS. B) peptidoglycan. C) PAMPs. D) AMPs. E) flagellin.

D) AMPs

Which of the following statements is true? A) Innate defenses are enough to keep a person healthly. B) Adaptive defenses include humoral immunity only. C) Memory B cells are typically established when the B cell binds to an antigen. D) Adaptive defenses include both humoral and cellular immunity.

D) Adaptive defenses include both humoral and cellular immunity.

What is meant by the clonal expansion of a B cell? A) An activated B cell will kill infected host cells. B) An activated B cell will engulf and digest anything foreign. C) An activated B cell will immediately begin to produce antibodies. D) An activated B cell divides into cells that give rise to memory B cells and plasma cells.

D) An activated B cell divides into cells that give rise to memory B cells and plasma cells.

A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component? A) The complement system B) Skin barrier C) Inflammation D) Antibodies

D) Antibodies

Which of the following statements concerning phagocytosis is true? A) Phagocytes cannot ingest microorganisms unless they are coated with antibodies. B) Adherence always requires opsonization. C) Phagocytes ingest microorganisms by using protein transporters that are specific to the bacteria. D) Bacteria are digested when the phagosome fuses with a lysosome.

D) Bacteria are digested when the phagosome fuses with a lysosome.

Which cells directly attack abnormal cells in the body? A) Helper T cells B) B cells C) Phagocytes D) Cytotoxic T cells

D) Cytotoxic T cells

How does cytolysis occur via the complement pathway? A) Stimulation of the inflammatory response B) Disrupting cell wall of pathogens C) Triggering the release of histamine D) Formation of the MAC in invading cells, killing them

D) Formation of the MAC in invading cells, killing them

__________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form. A) Prostaglandins B) Cytokines C) Histamine D) Kinins

D) Kinins

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again? A) Antibodies that are "left over" from the last infection B) Plasma cells C) Dendritic cells D) Memory B cells

D) Memory B cells

Which of the following are functions of lectins? A) They attach to carbohydrates on some bacterial and viral surfaces. B) They act as opsonins for phagocytosis. C) They can activate C2 and C4. D) They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4. E) They produce antibodies. F) They produce factor P (properdin).

D) They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.

First line defenses have what aspect in common with each other? A)They involve unique cells that attack invading pathogens. B) They recognize specific pathogens. C) They involve the production of antibodies. D) They are physical barriers against invading pathogens.

D) They are physical barriers against invading pathogens.

Activation of C3a results in A) attraction of phagocytes. B) opsonization. C) increased blood vessel permeability. D) acute inflammation. E) cell lysis.

D) acute inflammation.

Activation of C3 results in __________. A) release of histamine and other pro-inflammatory chemicals B) formation of a membrane attack complex (MAC), which causes cytolysis of bacteria C) enhancement of phagocytosis via opsonization D) all of the listed choices

D) all of the listed choices

The process by which a phagocyte moves toward a chemical signal at the site of an infection is called A) digestion. B) exocytosis. C) adherence. D) chemotaxis. E) elimination.

D) chemotaxis.

After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT A) O2-. B) H2O2. C) OH. D) complement. E) HOCl.

D) complement.

Innate immunity A) provides increased susceptibility to disease. B) involves a memory component. C) involves T cells and B cells. D) is nonspecific and present at birth. E) is slower than adaptive immunity in responding to pathogens.

D) is nonspecific and present at birth.

A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes? A) lysozyme B) acidic skin secretions C) mucociliary escalator D) phagocytosis in the inflammatory response F) normal skin flora

D) phagocytosis in the inflammatory response

Innate immunity includes all of the following EXCEPT A) phagocytosis. B) inflammation. C) activation of complement. D) production of antibody. E) production of interferon

D) production of antibody.

Inflammation is part of the second line of defense that is activated when the first line of defense is breached. Julie's first-line defenses were damaged when her injury occurred. Which of the following represents the first line of defense? A) white blood cells B) platelets C) red blood cells D) skin and mucous membranes

D) skin and mucous membranes

Both the innate and adaptive defenses of the immune system work to prevent A) penetration by invading pathogens. B) colonization by pathogens. C) disease. D) the penetration and colonization by pathogens, and the diseases they cause.

D) the penetration and colonization by pathogens, and the diseases they cause.

All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT A) they initiate transcription. B) they initiate manufacture of antiviral proteins. C) they disrupt stages of viral multiplication. D) they are effective for long periods. E) they bind to the surface of uninfected cells.

D) they are effective for long periods

Normal microbiota provide protection from infection in each of the following ways EXCEPT A) they produce antibacterial chemicals. B) they compete with pathogens for nutrients. C) they change the pH of the environment. D) they produce lysozyme. E) they make the chemical environment unsuitable for nonresident bacteria.

D) they produce lysozyme.

A chill is a sign that A) blood vessels are dilating. B) body temperature is falling. C) the metabolic rate is decreasing. D)body temperature is rising. E) body temperature is not changing.

D)body temperature is rising.

Which complement protein is used as an opsonin? A) C3a B) C5b C) C7 D) C2a E) C3b F) C4a

E) C3b

Which of the following statements is TRUE? A) All three types of interferons have the same effect on the body. B) Beta interferon attacks invading viruses. C) Alpha interferon promotes phagocytosis. D) Alpha interferon acts against specific viruses. E) Gamma interferon causes bactericidal activity by macrophages.

E) Gamma interferon causes bactericidal activity by macrophages.

All of the following protect the skin and mucous membranes from infection EXCEPT A) multiple layers of cells. B) the "ciliary escalator." C) saliva. D) tears. E) HCl.

E) HCl.

antibodies directly interact with which innate defenses? A) The complement system B) First-line defenses C) Phagocytosis, inflammation, and the complement system D) Phagocytosis E) Phagocytosis and the complement system F) Inflammation

E) Phagocytosis and the complement system

Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial A) cell membrane. B) DNA. C) capsule. D) ribosomes. E) cell wall.

E) cell wall.

The swelling associated with inflammation decreases when the fluid A) is transported into macrophages. B) returns to the blood. C) is excreted in urine. D) is lost as perspiration. E) goes into lymph capillaries.

E) goes into lymph capillaries.

Mucous membranes are a part of A) the complement system. B) humoral immunity. C) cell-mediated immunity. D) adaptive defense. E) innate defense.

E) innate defense.

Activation of C5-C9 results in A) activation of C3. B) phagocytosis. C) inflammation. D) fixation of complement. E) lysis of microbial cells.

E) lysis of microbial cells

Macrophages arise from which of the following? A) basophils B) eosinophils C) neutrophils D) lymphocytes E) monocytes

E) monocytes

All of the following are iron-binding proteins found in humans EXCEPT A) hemoglobin. B) lactoferrin. C) transferrin. D) ferritin. E) siderophorin.

E) siderophorin.

All of the following are true regarding NK cells EXCEPT A) they are found in tissues of the lymphatic system. B) they are a type of lymphocyte. C) they have the ability to kill infected body cells and some tumor cells. D) they release toxic substances that cause cell lysis or apoptosis. E) they destroy infected body cells by phagocytosis.

E) they destroy infected body cells by phagocytosis.

An example of a TLR would be peptidoglycan found in the cell wall of gram-positive bacteria. True False

false

Complement proteins in their intact and unactivated form act as opsonins by binding to microorganisms and promoting phagocytosis. True False

false

Digestion of microorganisms occurs in phagosomes. True False

false

The inflammatory response can only be triggered by an infection. True False

false

Which of the following exhibits the highest phagocytic activity? A) eosinophils B) macrophages C) basophils D) erythrocytes E) neutrophils

macrophages

Aspirin alleviates pain, inflammation, and fever by inhibiting prostaglandins. True False

true

Histamine and kinins cause increased blood flow and capillary permeability. True False

true

Ingestion of certain lactic acid bacteria (LABs) has been shown to be beneficial for function and health of the intestinal tract. True False

true

Maturation of stem cells into mature blood cells occurs in the red bone marrow. True False

true

Microorganisms that are members of the normal microbiota are also known to cause disease. True False

true