MCB2000 - Labs Final 8-13

Tears, saliva, mucus, and breast milk contain the enzyme _____________ that destroys certain bacteria.

lysozyme

Which first-line defense molecules produced by the immune system kill pathogens, and pathogens rarely become resistant to them?

AMPs

Which subcategory of first-line defenses does skin belong to?

physical barriers

Eosinophil

B (bi-lobed nucleus red-orange staining)

Neutrophil

A (Highly phagocytic)

Dendritic cell

F (ruffled membrane)

Monocyte

E (Large horseshoe shaped)

Basophil

C (bi-lobed nucleus, obscured by dark purple granules)

Mast cell

D (circular nucleus)

Lymphocyte

G (NK cells, B cells, T cells; small cells...)

Swollen ________ indicate that a foreign antigen is present, and leukocytes are rapidly multiplying to mount an immune response.

lymph nodes

The thymus and bone marrow are considered _________ lymphoid tissue.

primary

The majority of secondary lymphoid tissue is called ________, and includes Peyer's patches, tonsils, and the appendix.

MALT

Which granulocyte when stained exhibits red-orange granules, is moderately phagocytic, and attacks allergens and parasites?

eosinophils

Which granulocyte contains granules packed with histamine, that stain dark purple?

basophils

Which agranulocyte has a large horseshoe-shaped nucleus, and matures into either fixed or wandering macrophages?

monocytes

Signaling proteins that support cell-to-cell communication and initiate and coordinate immune responses are called ___________. Examples of these signaling proteins are interleukins and interferons.

cytokines

Which complement pathway has complement proteins that are directly activated by interacting with a pathogen?

alternative pathway

Which of the following is NOT a hallmark sign of inflammation?

fever

Fever-inducing agents released by certain microbes are called ___________.

pyrogens

______ cells are involved in cell-mediated immunity and ______ cells are involved in humoral immunity.

T; B

T cells can be classified by certain glycoproteins on their surface called clusters of differentiation (CD). T helper cells are classified as __________, and T cytotoxic are classified as __________.

CD4/CD8

What is the function of activated macrophages in cell-mediated immunity?

enhances phagocytic activity

Once T or B cells are activated, they proliferate and differentiate into active immune cells and ___________ cells that protect the body from reinfection from the same pathogen.

memory

T helper cells produce cytokines that signal B cells to produce plasma cells, and T ________ cells, that function to destroy infected cells, cancer cells, and transplanted tissues.

cytotoxic

The T helper cell subclass that stimulates B cells to proliferate and differentiate is called ________.

TH2

Which of the following is a function of antibodies?

all answers are functions of antibodies

Which antibody isotype can be monomeric or dimeric, and is the primary antibody found in breast milk?

IgA

Which antibody isotype can be monomeric or pentameric, and is produced early in infection?

IgM

Various mechanisms used by the host to defend against unwanted pathogens is called __________.

immunity

First-and second-line defenses are considered ___________.

innate immunity

Which of the following is not considered a part of innate immunity?

cytotoxic T-cells

Which of the following doesn't describe an action of first line-innate mechanical defenses?

digesting

Which type of first-line innate defenses does stomach acid belong to?

chemical barriers

Which of the following is NOT a molecular second-line innate defense?

lysozyme

Which of the following leukocytes is part of cellular second-line innate immunity?

neutrophils

Which type of cytokines interfere with viral replication in virus infected cells?

interferons

What is the innate immune function of ferritin in the blood?

binds free iron

Which of the following is not a complement pathway?

primary pathway

Which of the following in not an outcome of complement cascade activation?

fever

What is the outcome when a MAC complex is formed in a cell?

cell lysis

A molecule that stimulates an immune response is called __________.

an antigen

T cell and B cell receptors only recognize one type of ____________.

epitope

The cellular and humoral responses proceed through four stages of activation. Put the following stages in the order that they occur:

A) Antigen elimination and memory

B) Antigen presentation

C) Lymphocyte differentiation and proliferation

D) Lymphocyte activation

B, D, C, A

What category of immune deficiencies results from genetic causes?

primary immunodeficiency

What category of autoimmune diseases results in damage to diverse tissues throughout the body?

systemic

The cause of autoimmune diseases is unclear, but genetic predisposition, and exposure to ________________ may lead to these disorders.

certain infectious agents

The body's response to an antigen which is beyond what is considered normal is called a/an _________ response.

hypersensitivity

It is unclear why hypersensitivities develop, but genetics and environmental factors may play a role. Another proposed factor suggests that individuals living in developed countries may have weaker immune systems due to accessibility of clean food, and water, antibiotics, and minimized exposure to diseases. This is known as the __________ hypothesis.

hygiene

When an allergen is recognized by the immune system, it mounts a humoral response producing IgE antibodies which bind to mast cells or basophils. Upon subsequent exposure, the allergen binds to the IgE located on the mast cell or basophil which causes degranulation of chemical mediators. Name the chemical mediator blocked by Benadryl.

histamine

Systemic anaphylaxis is also known as _______________.

anaphylactic shock

Conditions such as asthma and seasonal allergies are caused by what type of hypersensitivity reaction?

type I

What would likely occur if an individual with type A blood receives type B blood during a transfusion?

hemolysis of RBCs

ABO blood incompatibility reactions are an example of what type of hypersensitivity reaction?

type ii

What would happen the FIRST time an Rh- woman is pregnant with an Rh+ fetus?

antibodies to Rh factor would develop in the mother

When can hemolytic disease of the newborn occur?

when a previously sensitized Rh- woman is pregnant with her second and subsequent Rh+ fetus

Name the condition caused by generation of an immune response against administered medications such as antitoxins and penicillin?

serum sickness

What type of hypersensitivity reaction is caused by the complexing of soluble antigens with antibodies that are deposited into tissues?

type III

What type of hypersensitivity reaction is responsible for autoimmune conditions such as rheumatoid arthritis and lupus?

type III

____________ are small molecules that are in-and-of themselves incapable of eliciting an immune response.

Haptens

What type of hypersensitivity reaction is associated with transplant rejection?

type IV

What type of hypersensitivity reaction is associated with allergic contact dermatitis?

type IV

What type of hypersensitivity reaction is the only one that isn't antibody-mediated?

type IV

Which type of hypersensitivity reaction is mediated by IgE antibodies bound to mast cells or basophils?

type I

Type I diabetes is an autoimmune disorder where certain insulin-producing cells in the pancreas are recognized as non-self and are destroyed. Which type of cell-mediated hypersensitivity reaction is responsible for Type I diabetes?

type IV

Your patient has a severe headache, high fever, and a stiff neck. You suspect they have meningitis. You order a lumbar puncture and have the cerebrospinal fluid (CFS) Gram stained. Gram-positive cocci are observed. Why is Gram staining alone not enough to identify an unknown organism?

there are many species of bacteria that have the same Gram stain reaction and morphology

What type of growth media contains components that only allow certain bacteria to grow?

selective media

What type of growth media permits growth of multiple types of bacteria but contains components that allow you to distinguish certain properties based on the appearance of the media after bacteria are grown?

differential media

Which set of results represents bacterial growth on selective media?

plate set 1

Which set of results represents bacterial growth that distinguishes different bacteria based on colony morphology?

plate set 2

What enzyme breaks down hydrogen peroxide (H2O2) into water and oxygen?

catalase

The catalase test is used to differentiate between

staphylococci from streptococci

True or False? Streptococci are catalase positive and staphylococci are catalase negative.

false

Using your knowledge of the catalase test, which of the following bacteria would be catalase positive? Select all that apply

- Staphylococcus aureus

- Staphylococcus epidermidis

Which enzyme protects bacteria from the toxic by-products of oxygen metabolism?

catalase

True or False? Anaerobic bacteria are catalase negative.

true

Why should you be careful not to touch the inoculating loop to a blood agar plate while testing for catalase?

RBCs contain catalase yielding false positive results

Which sample is catalase positive?

sample B only

The biochemical test in the image is used to detect the presence of an enzyme that converts hydrogen peroxide into water and oxygen. Using your knowledge of the test and the observed results, name the enzyme.

catalase

Phenylethyl alcohol (PEA) agar inhibits growth of Gram-negative bacteria, but allows growth of Gram-positive bacteria.

True or False? PEA is a selective media.

True

Phenylethyl alcohol (PEA) agar inhibits growth of Gram-negative bacteria, but allows growth of Gram-positive bacteria. If you streaked a mixed culture containing Klebsiella aerogenes and Staphylococcus aureus on PEA agar, which of the bacterial species would grow?

Staphylococcus aureus only

Which of the following media tests for hemolysins?

blood agar

Blood agar distinguishes the different degrees of red blood cell destruction. What type of media is blood agar?

differential media

You inoculate a patient sample on a blood agar plate. After incubation, you observe a greenish-brown discoloration of the blood around the colonies. What hemolysis pattern is observed?

alpha hemolysis

You inoculate a patient sample on a blood agar plate. After incubation, you observe complete clearing of the blood around the colonies. What hemolysis pattern is observed?

beta hemolysis

You inoculate a patient sample on a blood agar plate. After incubation, there is bacterial growth, but no visible change to the media. What hemolysis pattern is observed?

gamma hemolysis

beta hemolysis

complete breakdown of rbc

gamma hemolysis

unable to breakdown rbc

alpha hemolysis

partial breakdown of rbc

Bile esculin agar (BEA) is a selective and differential media. What bacteria does it select for?

bile resistant bacteria

Bile esculin agar (BEA) is a selective and differential media. What does it differentiate?

the ability or inability of bacteria to hydrolyze esculin

These are the results of bacterial samples inoculated on bile esculin agar (BEA). Which tube(s) is/are positive for esculin hydrolysis?

tube 1 only

These are the results of bacterial samples inoculated on bile esculin agar (BEA). Which tube(s) is/are negative?

tube 2 and tube 3

These are the results of bacterial samples inoculated on bile esculin agar (BEA). Why is tube 3 considered a negative result?

there must be at least 50% black-colored media to be considered positive

What dye is DNA bound to in DNase agar?

methyl green

These are the results of two samples inoculated on DNase agar. What can you conclude about sample A?

sample A is negative for DNase

What component in mannitol salt agar (MSA) is used to select for certain types of bacteria?

7.5% salt

What type of bacteria does mannitol salt agar select for?

halotolerant bacteria

These are the results of three bacterial specimens inoculated on mannitol salt agar (MSA). Which plate(s) has/have bacteria that are halotolerant?

plate A and plate B

These are the results of three bacterial specimens inoculated on mannitol salt agar (MSA). Which plate(s) has/have were inoculated with bacteria that are NOT halotolerant?

plate C only