BIO 212: Module 6- Homework
How is an antiseptic different from a disinfectant?
An antiseptic is used to remove or kill microorganisms on tissue, whereas a disinfectant is used to remove or kill microorganisms on inanimate objects.
Classify each of the following as a characteristic of one of the five immunoglobulin classes.
IgG: - Most abundant Ig ( Immunoglobulin ). - Neutralizes toxins. - Opsonizes bacteria. - Activates complement. IgM: - First to appear after antigen stimulation. - Activates complement. - Involved in the process of Agglutination. IgA: - Secretory antibody. - Protects external surfaces. IgD: - B cell recognition of antigen. IgE: - Allergies - Immunoglobulin produces during allergic reaction.
The many microorganisms that live in close association with humans are termed normal human microbiota or ____________ .
Microflora
Which type of antibiotic is most likely to target the pathogen without causing a decrease in the normal microbiota?
Narrow spectrum
The ____________ is the primary protective barrier against potential pathogens. Keratin and ____________ on the outer layer make the skin waterproof and virtually impenetrable by most microbes. The ____________ also contribute to the defenses by outcompeting for resources.
Skin; sebum, microbiota
The microbial link between a diet rich in red meat and atherosclerosis is that ________.
microbes that thrive on high levels of L-carnitine produce trimethylamine, which is metabolized to trimethylamine N-oxide in the liver and has been shown to accelerate atherosclerosis in mice
Which of the following would affect the size of a zone of inhibition around an antiseptic or disinfectant disk?
- The concentration of chemical in the disk - The cellular target of the chemical - How quickly the chemical diffuses through the agar - The depth of the agar
More than one factor may contribute to the second signal in activating T cells, but the most important seems to be the B7 (CD80) protein on the surface of an APC, which binds to the ___________ receptor on the T cell.
CD28
For T cytotoxic cells to be activated, an endogenous (cytoplasmic) antigen is presented in class I MHC molecules on the APC, and the _____ coreceptor on the T cell interacts with the antigen-bound MHC molecule on the APC to induce CTL function.
CD8
The acute inflammatory response begins when injured tissue releases chemical signals called ____________ .
Chemokines
After this migration occurs, other white blood cells are then attracted to the area by the release of ____________ .
Chemotaxins
A scientist wants to demonstrate the important relationship between an individual's microbiome and the healthy functioning of their central nervous system. Which experiment best supports their hypothesis?
Compared to conventional mice, germ-free mice demonstrate pathological behaviors in the areas of socialization, anxiety and depression, that can be normalized when populated with gut biota.
The _________ regions of an antibody have amino acid sequences that do not vary significantly between antibodies of the same class.
Constant
The stuck cells then squeeze through the capillary wall in the process of ____________ .
Diapedesis
Staphylococcus also are found in the nasopharynx, along with a group of nonpathogenic ____________ that resemble Corynebacterium.
Diptheroids
In response, capillaries dilate and fluids move into the surrounding tissues creating swelling called ____________ .
Edema
A large zone of inhibition around a disk containing disinfectant generally indicates that the bacteria being tested is resistant to the disinfectant.
False
Both neutrophils and macrophages are active phagocytic cells. When comparing tissue distribution for these two cell types, neutrophils predominantly take up residence in specific tissues once they mature, whereas macrophages remain in the blood until they are stimulated to migrate.
False
Individuals are predisposed to house certain species of microbes; switching from a high-fiber diet to one high in saturated fats will not change the microbial population of the gut.
False
To date, probiotics have successfully been used in humans, but not animals.
False
To date, probiotics have successfully been used in humans, but not animals. Group starts
False
When testing an organism with several different antibiotics, the antibiotic that produces the largest zone is the one that the microorganism is most sensitive to.
False
A person lacking Paneth cells would be more likely to get an infection of their ________.
Gastrointestinal tract
The major histocompatibility complex (MHC) is a collection of _________ that code for the self/non-self recognition potential of an animal.
Genes
The immunoglobulin receptor molecules on the B-cell surface associate with other proteins known as the ________.
Ig-alpha/Ig-beta heterodimer proteins
Data from numerous germfree animal studies demonstrate that colonization of the vertebrate host intestine with bacteria stimulates the host ________ ________.
Immune system
Which of the following is true about the role of B cells in immunological tolerance?
Immunologic tolerance is often maintained only within the T-cell population, sustaining tolerance because it denies the help essential for antibody production by self-reactive B cells.
Categorize the following molecules and cytokine functions according to the role they play in signal transduction mechanisms.
Innate resistance: -TNF -IFN - IL-1 - Enhanced inflammatory response Adaptive immunity: - IL-2 - IL-12 - Differentiation of T-cells Hematopoiesis: - IL-3 - Stem cell differentiation - CSF-1
These white blood cells produce ____________ , which allow them to bind to the selectin-positive epithelial cells in a process called ____________ .
Intregens; margination
The genitourinary tract harbors some organisms with the major organism ____________ of the vagina being important in lowering pH and preventing fungal growth.
Lactobacillis
Our constant need for nutrients means that with every bite we consume, thousands of potential pathogens are entering our system. The stomach has very ____________ pH, however many pathogens are protected by the food particles that carry them. Fortunately ____________ provide an onslaught of enzymes, cells, and molecules to purge microorganisms with the help of ____________ .
Low; GALT; peristalsis
Many different components play a role in the mammalian host immune system. Match the components of an immune response with a description of the role that they play.
Lysozyme- an antimicrobial chemical Antibody- glycoprotein that binds to a specific antigen Antigen- a foreign substance that provokes an immune response Leukocytes- function in both innate and adaptive immunity
The skin surface is dry and salty, and glands release enzymes such as __________ as well as antimicrobial peptides called _____________.
lysozymes; cathelicidins
Cytokines are soluble substances that play important roles in communication in the host resistance systems. Match the specific cytokines with the role that they play.
cell recruitment and direction of movement growth and differentiation of leukocytes increase immunity to viral infection produced by one leukocyte to influence another increase coagulation response
The lower respiratory tract is not sterile but has limited microbiota, since mucus, ___________ epithelial cells, and alveolar _____________ are all utilized for protection from microbial invasion.
ciliated; macrophages
Macrophages and ____________ cells play a crucial role in bridging the innate immune responses with adaptive immunity.
dendritic
One method for determining the impact of microorganisms routinely cultured from humans is to evaluate the consequences of their colonization in the absence of other organisms, which can be accomplished using _________ animals.
germfree
The importance of the human gut microbiota on metabolism is that ________.
human cells metabolize relatively few molecules into usable calories; most of our cellular energy is derived from microbial metabolism
An ___________ presenting cell, such as a macrophage, dendritic cell, or B cell, takes in the antigen or pathogen by receptor-mediated endocytosis or phagocytosis and produces antigen fragments by digestion in the phagolysosome.
Antigen
Constant inhalation makes the ____________ tract vulnerable to attack by microbes. ____________ bathes the inner lining with sticky mucous to trap invaders and prevents them from descending to the lungs. In the event of a breach, ____________ lie in wait.
Respiratory; MALT; alveolar macrophages
These signals stimulate the cells lining the capillaries to display ____________ on their surface, which attract wandering ____________ .
Selectins; neutrophils
The most common skin bacteria include members of the ____________ genus, namely S. aureus and S. epidermidis.
Staphylococcus
Which of the following statements is correct about the development of T cells?
T cells differentiate into progenitor cells destined to become (1) natural T regulatory (Treg) cells, (2) natural killer T (NKT) cells, (3) gamma/delta T cells, and (4) alpha/beta T cells.
There, the antigens are presented to naïve ____________ , which respond by stimulating additional lymphocytes to recognize that specific antigen and retain a ____________ of its antigenic signature.
T lymphocytes, memory
Which of the following statements is correct about immunological tolerance?
T-cell tolerance induced in the thymus and B-cell tolerance induced in the bone marrow is called central tolerance.
Assess the following statements and classify them according to whether they refer to T-cell receptors or B-cell receptors.
Tcell receptor: - Heterodimeric α/β polypeptides - Cytoplasmic tails interact with cd3 polypeptides - Six accessory polypeptides B cell receptor: - Igα/Igβ heterodimers - Transmembrane immunoglobin - Monomeric IgM and IgD.
Which of the following statements is correct about the types of molecules that can serve as antigens?
The ability of a molecule to function as an antigen depends on its size, structural complexity, chemical nature, and degree of foreignness to the host.
Which of the statements is false concerning the role of the spleen in immune function?
The spleen is a primary lymphoid organ
The skin harbors resident bacteria that normally grow on skin and ____________ bacteria that are only temporarily present.
Transient
A product is defined as a probiotic if it is a compound that enhances the colonization and positive health benefits of the microbiome.
True
What two factors increase the effectiveness of a disinfectant on microorganisms?
- Concentration of disinfectant - Time of exposure
The activation of self-reactive T and B cells that, following stimulation by genetic or environmental triggers, results in actual tissue damage is known as _______ disease.
Autoimmune
An example of a molecule that acts as a hapten is ________.
Penicillin
The complement system acts in a cascading fashion to ________. (Check all that apply.)
- Enhance phagocytosis - Lyse cell membranes of target cells - Produce inflammatory peptides
Place the events of the inflammatory response in the correct order that they occur.
1. Chemokines released from damaged tissue, leukocytes and bacteria. 2. Selectins on endothelial cells attach to integrins on neutrophils. 3. Neutrophils undergo margination and diapedesis. 4. Neutrophils attack the pathogens. 5. Tissue healing and repair
Rank these from the easiest to remove or destroy to the most difficult to remove or destroy.
1. Enveloped viruses (such as influenza virus) 2. Mycobacterium tuberculosis 3. Prions
Leukocytes, or white blood cells, are the cells responsible for the innate defenses. Match the different leukocytes with a key characteristic.
Vasoactive mediator - mast cell Important in defense against protozoa and helminths parasites - eosinophil A granulocyte that contains histamine - basophill Principal phagocyte responder in blood - neutrophils Mature into macrophages - monocytes Present antigens to lymphocyte - dendritic cell The largest phagocytic cell in body - macrophages
An antigen is best described as __________.
A defense molecule that eliminates foreign substances
Different locations of the human body use different resistance strategies to help protect the human host from microbial invaders. Match each strategy with the correct location in the human host.
Respiratory tract - Mucociliary system. Gastrointestinal tract - Peristalsis. Skin- Sodium Chloride. Genitourinary tract - presence of uric acid, fatty acid and mucins
Evaluate the statements below and choose those that correctly apply to pattern recognition molecules.
Nucleotide oligomerization domain (NOD)-like receptors and the retinoic-acid-induced gene 1 (RIG-1) receptors are located in the cytosol.
Which of the following statements is true about clonal selection of lymphocytes?
Once a lymphocyte has been released from its primary development site and is exposed to its specific antigen, it proliferates to form a clone (a population of identical cells derived from a single parent cell).
Artificially acquired _________ immunity results when an animal is vaccinated; that is, intentionally exposed to a foreign material and induced to form antibodies and activated lymphocytes.
Passive
In addition to these molecules, bradykinin is released into the area causing the production of ____________ that advance the inflammation response.
Prostaglandins
The ability to recognize a specific antigen and remember it in the future is a characteristic of the ________.
adaptive immune response
Bifidobacteria are an essential component of host defense against pathogens and are required for ________.
normal development of GALT
On the skin, Propionibacterium acnes converts lipids secreted by the oil glands to unsaturated fatty acids, such as ________ ________, that have strong antimicrobial activity against Gram-negative bacteria and some fungi.
oleic acid
Both cell types have membrane-bound ____________ (PRMs), which bind to the microbe-associated molecular patterns (MAMPs) of pathogen ____________ .
pattern recognition molecules, Macromolecules
After a B cell is activated by its specific antigen, the first type of antibody secreted is the _________ form of IgM.
pentameric
Once a pathogen is recognized by the phagocytic cell, the process of ____________ ends with the antigenic remains of the microbe being presented on the surface of the cell where it is carried to the ____________ tissue.
phagocytosis,lymphoid
The most important feature of antigen recognition by the host is that __________.
the immune system can recognize and distinguish between self-antigens and foreign antigens thereby avoiding autoimmune disease
