Bio 251 Exam 2 (New 2024/ 2025 Update)Questions and Verified Answers|100% Correct|Grade A+, Exams of Nursing

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Bio 251 Exam 2  (New 2024/ 2025 Update) Questions and Verified Answers|100% Correct | Grade A+ Which of the following statements about how the skin prevents disease is false? a) salt in sweat retards microbial growth b) the skin is the most common route for organisms to penetrate the body c) oil glands on the skin make it waterproof d) native microbes that live on your skin help protect you from infection - Correct Answer-b) the skin is the most common route for organisms to penetrate the body This antimicrobial protein is found at high levels in lacrimal secretions (tears) a) lysozyme b) defensins c) sebum d) C3b - Correct Answer-a) lysozyme Which component of the compliment system would stimulate neutrophils to phagocytize an attached cell? a) C5a b) C5b c) C3a d) C3b - Correct Answer-d) C3b Which of the following would prevent a microbe from activating the Alternative pathway of the compliment system? a) a bacteria that has an enzyme that degrades antibodies b) a bacteria that has a thick cell wall c) a bacteria that can prevent C3b from binding to it d) a bacteria that contain no mannose - Correct Answer-c) a bacteria that can prevent C3b from binding to it Which of the following is NOT a feature of the skin that allows it to serve as a barrier to infection? a) melanin in the skin is toxic to a bacteria b) sweat creates a sling environment that prevents non- halotolerant bacteria from growing c) tight junctions in keratinocytes make the skin waterproof d) resident flora produce bacteriocins - Correct Answer-a) melanin in the skin is toxic to a bacteria d) increased sensitivity of nociceptors - Correct Answer-b) increasing vascular permeability Put the steps of Phagocytosis in order. Chemotaxis Exocytosis Recognition and Attachment Engulfment (endocytosis) Destruction and Digestion Phagosome maturation and phagolysosome formation - Correct Answer-Chemotaxis Recognition and Attachment Engulfment (endocytosis) Phagosome maturation and phagolysosome formation Destruction and Digestion Exocytosis What are examples of Antigen Presenting Cells? - Correct Answer-Mast cells, Dendritic cells, Macrophages, B-cells Which of the following is NOT a way that antibodies assist the immune system in getting rid of pathogens? a) labelling pathogens for phagocytosis (opsonization) b) poking holes in the cell membrane and lysing bacteria directly c) binding to viral coat proteins and preventing them from being able to enter cells d) binding to flagella and fimbrae and preventing movement and adherence - Correct Answer-b) poking holes in the cell membrane and lysing bacteria directly Which of the following pathogens could initiate an antibody response without Helper T-cells? a) HIV b) Gram- organisms c) Gram+ organisms d) Helper T-cells are not normally for an antibody response - Correct Answer-b) Gram- organisms Which of the following statements about B-cells is false? a) B-cells mature in the bone marrow b) B-cell receptors are all identical c) When activated, B-cells differentiate into plasma cells d) B-cells present foreign antigens on an MHCII - Correct Answer-b) B-cell receptors are all identical Suppose you are observing a patient who has a bacterial infection that begins to subside fairly quickly after becoming symptomatic. An analysis of their blood shows high levels of IgM specific to the bacteria, but undetectable levels of IgG and IgD. Two months after being discharged, the patient returns with another infection by the same bacteria. What would be reasonable to conclude? - Correct Answer-The patient's immune reaction happened through the T- independent pathway Know the following: IgM, IgG, IgA, IgE, IgD - Correct Answer-IgM- first antibody produced in response to an infection IgG- antibody that penetrates the placenta; abundant in blood and fluids; antibody of memory IgA- found in body secretions: mucus, tears, saliva, breastmilk for infants IgE- involved in allergic reactions IgD- poorly understood function Suppose that an antibody binds to a toxin molecule and prevents the toxin from binding to a receptor where it would have a negative effect. This is an example of: a) cross-linking b) hepatocyte c) dendritic cell d) neutrophil - Correct Answer-a) red blood cell The immune system cell most commonly associated with allergies is: a) neutrophil b) eosinophil c) basophil d) macrophage - Correct Answer-c) basophil Which of the following would be a common treatment for an autoimmune disorder? a) epinephrin b) antihistamines c) steroids d) theyroidectomy - Correct Answer-c) steroids Suppose that someone has a contact dermatitis latex allergy. Would you expect this condition to be diagnosable via a basophil degranulation assay? a) Yes, because latex allergies are localized type 1 hypersensitivities b) Yes, because although latex allergies are not IgE dependent they still operate through a basophil induced inflammation c) No, because as a localized reaction latex allergies only work through mast cells d) No, because latex allergies work through cytotoxic T cells - Correct Answer-d) No, because latex allergies work through cytotoxic T cells Mother/fetus Rh factor incompatibility is an example of what hypersensitivity: a) Type 1 b) Type 2 c) Type 3 d) Type 4 - Correct Answer-b) Type 2 What would likely be an appropriate treatment for a systemic type 1 hypersensitivity a) Epi-pen b) RhoGAM c) Anti-histamine cream d) there is no effective treatment for type 1 hypersensitivities - Correct Answer-a) Epi-pen Which of the following would be an example of a primary immunodeficiency? a) someone in the advanced stages of AIDS b) someone on immunosuppressive therapy for an organ transplant c) someone with a mutation in the gene that codes for the C3 protein of the compliment system d) all of these primary immunodeficiencies - Correct Answer-c) someone with a mutation in the gene that codes for the C3 protein of the compliment system Which of the follow statements is false? a) herd immunity only protects a population if most of the members have been vaccinated b) inactivated vaccines primarily work through humoral immunity c) children do not need vaccines if they breastfeed from a vaccinated mother d) vaccines are often ineffective in immunocompromised patients - Correct Answer-c) children do not need vaccines if they breastfeed from a vaccinated mother d) antimicrobial peptides - Correct Answer-d) antimicrobial peptides What is a chemical mediator that is secreted onto the surface of the skin? - Correct Answer-sebum Identify the complement activation pathway that is triggered by the binding of an acute-phase protein to a pathogen. a) classical b) alternative c) lectin - Correct Answer-c) lectin Histamine, leukotrienes, prostaglandins, and bradykinin are examples of what? - Correct Answer-chemical mediators that promote inflammation What are bacteriocins? - Correct Answer-antimicrobial peptides produced by normal microbiota TLRs (toll-like receptors) - Correct Answer-found on surface of sentinel cells, used to find infectious molecules/cell, OUTSIDE the cell NLRs (NOD-like receptors) - Correct Answer-found in cytoplasm of most cells, detects INSIDE the cell (flagella, peptidoglycan) RLRs (RIG-like receptors) - Correct Answer-found in cytoplasm to detect VIRAL components (ds RNA) Neutrophils - Correct Answer-most abundant circulating WBC NK cells- kills cells that fail to display self antigens on their surface Macrophages- phagocytic sentinel cell Basophils - Correct Answer-releases histamine in response to infection, involved in allergic reactions Macrophages - Correct Answer-sentinel cells that phagocytize foreign substances, dead cells, debris Eosinophils - Correct Answer-has an anti parasitic function B cells - Correct Answer-a lymphocyte processed in bone marrow and responsible for producing antibodies. Cytotoxic T-cells - Correct Answer-destroy cells infected with intracellular pathogens, made in thymus NK cells (natural killer cells) - Correct Answer-a lymphocyte that kills cells that do not present antigens/proteins (virally infected/cancerous) Type 1 hypersensitivity - Correct Answer-IgE mediated, triggering mast cell degranulation ex) food/drug allergies Type 2 hypersensitivity - Correct Answer-IgG and IgM antibodies directed against cellular antigens, leads to cell damage ex) red blood cell damage after transfusion w/ mismatched blood Type 3 hypersensitivity - Correct Answer-immune complexes of IgG and IgM antibodies and antigens are deposited in tissues, cascades into tissue damage ex) rheumatoid arthritis Type 4 hypersensitivity - Correct Answer-T cell mediated , TH1 cells secrete cytokines, which activate macrophages and cytotoxic T cells secondary immunodeficiency - Correct Answer-acquired later in life; result of infection (sometimes viral) or other stress on system (AIDs, malnutrition) natural active immunity - Correct Answer-immunity gained through illness and recovery natural passive immunity - Correct Answer-immunity gained from antibodies through placenta or breastmilk artificial active immunity - Correct Answer-immunity gained through a vaccine artificial passive immunity - Correct Answer-immunity gained from an animal or another person Bacteriostatic - Correct Answer-a substance that inhibits bacteria from spreading Bacteriocidal - Correct Answer-a substance that kills bacteria Sterilization - Correct Answer-removal of ALL microbial life, including virus but not prions disinfection - Correct Answer-getting rid of MOST pathogens from a non-living object (kitchen) antisepsis - Correct Answer-getting rid of pathogens from skin or another living entity Sanitization - Correct Answer-removal of pathogens from objects to meet public health standards degerming - Correct Answer-removing, NOT killing, organisms through mechanical action (hwndwwashing) Pasteurization - Correct Answer-use of heat to destroy pathogens and reduce the number of spoilage microorganisms in foods and beverages preservation - Correct Answer-action that inhibits microbial growth in the future T-independent activation - Correct Answer--the activation of B cells without helper T cells, only produces IgM, but DANGEROUS -no class switching and no memory TH cells T-dependent activation - Correct Answer-high affinity B cells with class-switched antibodies Which of the following would have an MHC II? a) neutrophils b) macrophages c) dendritic cells d) basophils e) mast cells f) monocytes - Correct Answer-macrophages, dendritic cells, monocytes Which of the following chemical control agents is no longer in common use? a) peroxides b) halogens c) aldehydes d) heavy metals - Correct Answer-d) heavy metals