Chapter 11.3 Immune system

Which of the following is NOT a function of helper T cells? A. Phagocytize antigens B. Release cytokines to amplify the immune response C. Attract innate immunity cells to the site of infection D. Activate B cells and T cells, as well as induce their proliferation

A Helper T cells are there to assist both innate and adaptive immunityThey release cytokines to ramp up the immune response Functions of cytokines:Attract innate immunity cells e.g. macrophages, dendritic cells to where the identified antigen is presentStimulate clonal selection and proliferation of B cells and T cells

Which of the following is NOT true of the membrane attack complex? A. It is part of adaptive immunity B. It creates holes, which allow fluid and salts to enter the pathogen C. It causes pathogens to swell and lyse D. Membrane attack complex proteins gather on the membrane of a pathogen

A Membrane attack complex proteins group on the membrane of a pathogen This allows salts and fluids to enter the pathogen This causes swelling within the pathogen, causing the pathogen to burst The complement system is part of innate immunity.

Which of the following is NOT a disease caused by bacteria? A. Smallpox B. Tuberculosis C. Gonorrhea D. Syphilis

A These are all kinds of harmful microscopic enemies (virus, bacteria etc...) that can cause diseases. Many pathogens are bacterial in nature; common examples of diseases that are caused by bacteria include tuberculosis, gonorrhea, and syphilis

.Which disease is caused by Treponema pallidum? A. Measles B. Syphilis C. Gonorrhea D. Tuberculosis

B Syphilis is a sexually transmitted disease (STD); it is caused by Treponema pallidum. Gonorrhea is another STD that is caused by Neisseria gonorrhoeae. Tuberculosis is a disease that often affects your lungs and can lead to death if left untreated; it is caused by the acid-fast bacterium Mycobacterium tuberculosis.

Which of the following is NOT a function of antibodies? A. Tag the specific corresponding antigen for removal B. Phagocytose the specific antigen C. Coat the antigen in antibodies to neutralize them D. Activate the complement system

B After antibodies are released into the humor, they can: Tag the specific corresponding antigen for removal → signal it should be phagocytosed Coat the antigen in antibodies, which neutralizes them Activate the complement system These functions all share a common goal — annihilate the pathogen containing the specific antigen.

What is another way to call cytotoxic T cells? A. CD4 cells B. CD8 cells C. TH1 cells D. TH2 cells

B If an antigen is presented by MHC I: T cells activate and become cytotoxic T cells, also called CD8 cellsThey are called CD8 cells because they form a co-receptor CD8 in addition to its original TCR CD8 cells will recognize every cell containing the presented antigen and kill it

Which of the following of natural killer cells helps to create holes in pathogenic cell membranes? A. Lysozyme B. Lactoferrin C. Perforin D. Granzymes

C Perforin perforates (poke holes in) pathogenic cell membranes, causing cell lysis (cell breakdown).

In complement system, proteins activate each other through the release of __________. A. Interferons B. Bradykinins C. Cytokines D. Prostaglandins

C Although proteins are much smaller in size compared to cells, they can generate a big effect by 'turning each other on' through a cascade series of activation. They activate each other through the release of cytokines (intracellular signaling molecules)

Which of the following helps to distinguish between self and non-self cells? A. Interferon B. Toll-like receptor C. Major histocompatibility complex D. Perforin-mediated cytotoxicity

C Our immune system is normally programmed to recognize its own cells and not attack them. How does it distinguish between self and non-self cells? It accomplishes this through the major histocompatibility complex (MHC) molecule found on the surface of cells.

What is the difference between antibodies and BCRs? A. BCRs are secreted by plasma cells, whereas antibodies are secreted by memory B cells B. BCRs can bind to specific antigens, whereas antibodies can bind to any antigen C. BCRs are bound to the B cell membrane, whereas antibodies circulate freely D. BCRs can only bind to antigens presented by APCs, whereas antibodies can bind to free antigens

C Plasma cell release antibodies, also known as immunoglobulins Structurally, BCR and antibodies are identical. BCR is bound to the B cell membrane, whereas they are called antibodies when they are freely secreted. Antibodies circulate in the blood and lymph

Which of the following is TRUE of T cells? A. TCRs on each T cell can bind to different kinds of antigens B. T cells do not go through the clonal selection, unlike B cells C. T cells cannot recognize free-floating antigens D. Each T cell can have different types of TCRs

C Similar to B cells, T cells have T cell receptors (TCR) on their surfaces. Every T cell has a unique and uniform TCR that binds to only one kind of antigen. Hence, T cells also go through the clonal selection. However, unlike B cells, T cells are more needy. T cells cannot recognize free-floating antigens; they can ONLY bind to antigens presented by antigen-presenting cells (APCs).

Which of the following do sebaceous glands secrete? A. Sweat B. Cerumen C. Sebum D. Androgen

C The skin possesses sebaceous glands: Oil (sebum) itself serves as an additional physical barrier The fatty acids in sebum possess antimicrobial properties

Which disease affects the lungs and is caused by an acid-fast bacterium? A. Syphilis B. Measles C. Tuberculosis D. Gonorrhea

C Tuberculosis is a disease that often affects your lungs and can lead to death if left untreated; it is caused by the acid-fast bacterium Mycobacterium tuberculosis

Which class of antibodies can provide the newborn baby with passive immunity during breastfeeding? A. IgE B. IgD C. IgG D. IgA E. IgM

D. IgA

Which class of antibodies are the most abundant in body secretions? A. IgD B. IgM C. IgA D. IgE E. IgG

IgA Most abundant in body secretions e.g. breastmilk, tears, saliva Functions to bind and stop pathogens externally before they enter circulation

Which class of antibodies is the most abundantly found in circulation? A. IgG B. IgD C. IgE D. IgM E. IgA

IgG Monomer Most abundant antibodies found in circulation e.g. blood, lymph

CD8 cells and natural killer cells?

Similarities: Both release:Perforin: perforates (poke holes in) pathogenic cell membranes, causing cell lysis (cell breakdown)Granzymes: a protease which stimulates a target cell to undergo apoptosis (programmed cell death)—useful for killing cancerous cells Differences: NK cells react faster than CD8 cells because they do not require antigen-presentation and activation CD 8 cells are more specific than NK cells because they target a specific antigen on a pathogen

Which of the following do NOT have MHC II molecules? A. B cells B. Natural killer cells C. Dendritic cells D. Macrophages

two kinds of antigen-presenting cells (APCs) that act as a bridge between the innate and adaptive response — macrophages and dendritic cells