A. Incorrect! The resistance that an individual acquires during life is known as specific immunity.

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1 Microbiology - Problem Drill 13: Innate Immunity No. 1 of Which type of immunity is attributed to the Anatomic, Physiologic, Phagocytic and inflammatory barriers? A. Specific Immunity B. Adaptive Immunity C. Non-specific Immunity D. Acquired Immunity The resistance that an individual acquires during life is known as specific immunity. It is other name of specific immunity. C. Correct! These four types of barriers help to prevent our body from the entrance and establishment of infectious agents. It is the other name of specific immunity. The term, Innate immunity, refers to basic disease resistance that an individual possesses by virtue of his/her birth. It is the first line of defense against infection. Innate immunity is comprised of four types of defensive barriers: anatomic, physiologic, phagocytic and inflammatory barriers. 1. Anatomic barriers tend to prevent the entry of pathogens inside our body and are known as the first line of defense against infection. The skin and mucous membranes are included in this category. 2. The physiologic barriers that contribute to innate immunity include temperature, ph, and various soluble factors. 3. Phagocytes engulf the foreign materials and destroy them; this is known as phagocytic response. 4. Tissue damage caused by a wound or by an invading pathogenic microorganism induces a complex sequence of events collectively known as the inflammatory response.

2 No. 2 of Which components of sebum maintain the ph of the skin between 3 and 5? A. Lactic acid and fatty acids B. Lysine and Histidine C. Glucose and lactose D. ATP and GTP A. Correct! Lactic acid and fatty acid maintains the ph of the skin between 3 & 5, as they are acidic in nature. As they are basic amino acids. Glucose is a monosaccharide and lactose after break down yields glucose and galactose, they are not involved in maintaining the ph of the sebum. They are high energy compounds. The sebaceous glands are associated with the hair follicles and produce an oily secretion called sebum. Sebum consists of lactic acid and fatty acid, which maintains the ph of the skin between 3 and 5, this ph inhibits the growth of most organisms. A few bacteria that metabolize sebum live as commensals on the skin and sometimes cause a severe form of acne.

3 No. 3 of Which process of the cells takes up fluids from the surrounding medium and many molecules contained in it? A. Endocytosis B. Pinocytosis C. Phagosomes D. Vasodilation Process by which macromolecules contained within the extracellular tissue fluid are internalized by cells. B. Correct! Cells take up fluids from the surrounding medium and many molecules contained in it. It involves nonspecific cell invagination. In phagocytosis, a cell s plasma membrane expands around the particulate material to form large vesicles known as phagosomes A process in which there is an increase in the diameter of blood vessels is known as vasodilation. Various cells internalize (endocytose) and break down foreign macromolecules. Specialized cells such as blood monocytes, neutrophils, and tissue macrophages internalize i.e. phagocytose, kill and digest whole microorganisms. Phagocytosis is one type of endocytosis. Other forms of endocytosis are: Receptor Mediated endocytosis Pinocytosis: Cells take up fluid from the surrounding medium and many molecules contained in it. It involves nonspecific cell invagination.

4 No. 4 of Which type of the immune response includes Acute-Phase proteins, histamines, and kinins? A. Phagocytic response B. Physiologic response C. Anatomic response D. Inflammatory response Phagocytes engulf the foreign materials and destroy them; this is known as phagocytic response. The physiologic barriers that contribute to innate immunity include temperature, ph, and various soluble factors. Skin and mucous membrane are the two pillars of anatomic barriers. D. Correct! The events in the inflammatory response are initiated by various soluble chemical mediators listed in the question. Tissue damage caused by a wound or by an invading pathogenic microorganism induces a complex sequence of events collectively known as the inflammatory response. The events in the inflammatory response are initiated by various soluble chemical mediators like acutephase proteins, histamines, & kinins. Acute-phase proteins are the serum proteins; they increase dramatically in tissue damaging infections. Histamine is a chemical released by a variety of cells in response to tissue injury. They can bind to receptors on the near by capillaries and venules, causing vasodilation and increased permeability of capillaries. Kinins are small peptides present in blood plasma in an inactive form. Tissue injury activates this peptides, which then causes vasodilation and increased permeability of capillaries.

5 No. 5 of Which type of barrier is attributed to the Skin and mucous membranes? A. Inflammatory barriers B. Physiological barriers C. Phagocytic barriers D. Anatomical barriers Tissue damage caused by a wound or by an invading pathogenic microorganism induces a complex sequence of events collectively known as the inflammatory response. The physiologic barriers that contribute to innate immunity include temperature, ph, and various soluble factors. Phagocytes engulf the foreign materials and destroy them; this is known as phagocytic response. D. Correct! Anatomic barriers tend to prevent the entry of pathogens inside our body and known as first line of defense against infection. The skin and mucous membrane are included in this category. Anatomic barriers tend to prevent the entry of pathogens inside our body and known as first line of defense against infection. The skin and mucous membrane are included in this category. Skin: It consists of two layers, epidermis and dermis. They acts as mechanical barriers which retards the entry of microbes and also the acidic environment (ph 3-5) retards the growth of microbes. Mucus membranes of Conjunctivae, Alimentary tract, Respiratory tract, Urogenital tract, are lined by mucous membranes. Most pathogens enter the body by binding to and penetrating through mucous membranes.

6 No. 6 of Which is the antimicrobial substance that prevents and also destroys the growth of microorganism in our body? A. Complement B. Interferon C. Cryptidins D. Histamine Is a group of serum proteins that lyses microorganisms or facilitates phagocytes. They circulate in an inactive state in our body & can be activated by a variety of specific & nonspecific immunologic mechanisms. Is produced by virus infected cell, induces antiviral state in uninfected cells. C. Correct! Is an antimicrobial substance. Histamine is a chemical released by a variety of cells in response to tissue injury. It can bind to receptors on the near by capillaries and venules, causing vasodilation and increased permeability of capillaries. Various substances produced by the host body can destroy microorganisms and are known as antimicrobial substances. Anti-microbial substances which directly destroy microorganism are: Cryptidins and a-defensin, produced in the base of crypts of the small intestine, damages cell membranes. b-defensins, produced within skin, respiratory tract - also damages cell membranes. Surfactant proteins A & D, present in lungs, function as opsonins which enhance the efficiency of phagocytosis.

7 No. 7 of Which of the following soluble protein contribute to the physiological barriers of non-specific immunity? A. Sebum B. Interferon C. Histamine D. Acute-Phase proteins It is included under anatomical barriers. B. Correct! It is produced by virus infected cells and induces an antiviral state in uninfected cells. It is included under inflammatory barriers. It is included under inflammatory barriers. A variety of soluble factors contribute to non-specific immunity, among them the soluble proteins lysosome, interferon, & complement. They are the group of molecules involved in signaling between cells of the immune system, and in protection against viral infections. Among the many functions of interferon is the ability to bind to nearby cells and induce a generalized antiviral state.

8 No. 8 of 10 8 A cytoplasmic vesicle containing degradative enzymes is known as a. A. Dermis B. Macrophage C. Phagosomes D. Lysosome Layer of skin containing blood vessels and sebaceous glands. Phagocytic cell found in tissues. Large vesicles containing ingested particulate material. D. Correct! It is the name of the vesicle containing the ingested particulate material. A small cytoplasmic vesicle found in many types of cells that contains hydrolytic enzymes like lysozyme, which play an important role in the degradation of material ingested by phagocytosis and endocytosis.

9 No. 9 of How do phagocytic cells distinguish between Self and Non-Self? A. Microbial patterns B. Diversity C. Memory D. Specificity A. Correct! Our body cells recognize invading microorganisms by recognizing common microbial patterns. It is the attribute of adaptive immunity. It is the attribute of adaptive immunity. It is the attribute of adaptive immunity. Our body cells recognize invading microorganisms by recognizing common microbial patterns like: LPS- lipopolysaccharide (associated with the outer membrane of Gram - bacteria) Mannose, fucose, and other sugar residues (not just absence/presence but also factors like spacing between sugars on the cell surface) Techoid acid (associated with the peptidoglycan cell wall of Gram+ bacteria) N-formyl peptides ( recall that all prokaryotic protein sequences begin with a formyl-methionine) These common microbial patterns are recognized by host proteins which have been termed Pattern Recognition Molecules (PRMs) or Pattern Recognition Receptors (PRRs).

10 No. 10 of Within a species, different races may show differences in susceptibility to infections; this is known as. A. Species immunity B. Acquired immunity C. Racial immunity D. Individual immunity Species immunity refers to the total refractoriness to a pathogen, shown by all the members of a species obtained as their birthright. The resistance that an individual acquires during life is known as specific immunity. C. Correct! Different races show differences in susceptibility to infections is known as racial immunity. The differences in innate immunity exhibited by different individuals in a race are known as individual immunity. It is genetic in origin.. Within a species, different races may show differences in susceptibility to infections. This is known as racial immunity, it is genetic in origin. By selection and inbreeding it is possible to develop races that possess high degrees of resistance or susceptibility to pathogens. Example: Genetic resistance to plasmodium falciparum malaria is seen in some parts of Africa & Mediterranean coast. This occurs due to the hereditary abnormality of red blood cells (sickling), prevalent in those areas. Which confers immunity to infection by the malarial parasite & may have evolved from the survival advantage conferred by it in a malarial environment? Solution