1.
Infection occurs when
Correct Answer
D. Pathogens enter and multiply in body tissues
Explanation
Infection occurs when pathogens, which are disease-causing microorganisms, enter the body tissues and start multiplying. This can happen through various routes such as contaminated objects or surfaces, ingestion of food or water containing microbes, or inhalation of microbes present in the air. Once inside the body, pathogens can cause harm by damaging cells, releasing toxins, or triggering an immune response. Therefore, the correct answer is that infection occurs when pathogens enter and multiply in body tissues.
2.
All infectious diseases
Correct Answer
C. Are caused by microorganisms or their products
Explanation
Infectious diseases are caused by microorganisms or their products. This means that the diseases are a result of bacteria, viruses, fungi, or parasites entering the body and causing an infection. These microorganisms can multiply and spread within the body, leading to various symptoms and complications. Understanding that infectious diseases are caused by microorganisms or their products is crucial in developing effective treatments and prevention strategies for these diseases.
3.
Which is not terminology used for resident flora
Correct Answer
A. Pathogenic flora
Explanation
The term "pathogenic flora" refers to microorganisms that can cause disease or infection in the host. On the other hand, "normal flora," "indigenous flora," and "normal microflora" all refer to the microorganisms that naturally inhabit the body without causing harm. Therefore, "pathogenic flora" is not a terminology used for resident flora.
4.
Endogenous infectios agents arise from microbes that are
Correct Answer
B. In patients own normal flora
Explanation
Endogenous infectious agents arise from microbes that are present in a person's own normal flora. Normal flora refers to the microorganisms that naturally reside on or within the human body without causing any harm. These microorganisms can include bacteria, fungi, and viruses. Under certain conditions, such as a weakened immune system or a disruption in the balance of the normal flora, these microbes can cause infections. Therefore, endogenous infections occur when the microbes from a person's own normal flora invade and cause illness or disease.
5.
Virulence factors include all of the following except
Correct Answer
B. Ribosomes
Explanation
Virulence factors are molecules or structures produced by pathogens that contribute to their ability to cause disease. Capsules, exoenzymes, endotoxin, and exotoxin are all examples of virulence factors. Ribosomes, on the other hand, are not considered virulence factors. Ribosomes are cellular structures found in all living organisms, including pathogens, and are responsible for protein synthesis. While ribosomes play a crucial role in the overall functioning of a cell, they do not directly contribute to the pathogenicity or disease-causing abilities of a microorganism.
6.
These bacteria are opportunistic pathogens. These microbes pose an increased threat for those suffering from cystic fibrosis
Correct Answer
A. Pseudomonas sp.
Explanation
Pseudomonas sp. is the correct answer because it is known to be an opportunistic pathogen, meaning it typically causes infections in individuals with weakened immune systems or underlying health conditions. In this case, the question specifies that the bacteria pose an increased threat for those suffering from cystic fibrosis, indicating that Pseudomonas sp. is the most likely culprit. Enterobacteriaceae, Staphylococcus sp., and Streptococcus sp. may also be pathogenic, but they are not specifically mentioned in relation to cystic fibrosis or opportunistic infections.
7.
Which STD is estimated to be the most prevalent in cases each year in the USA
Correct Answer
C. Human papillomavirus
Explanation
Human papillomavirus (HPV) is estimated to be the most prevalent STD in cases each year in the USA. HPV is a common virus that can be transmitted through sexual contact. It is estimated that around 79 million Americans are currently infected with HPV, and approximately 14 million new cases are reported each year. HPV can lead to various health issues, including genital warts and certain types of cancer. Therefore, it is crucial to raise awareness about HPV and promote preventive measures such as vaccination and safe sexual practices.
8.
The time from when pathogen first enters the body and begins to multiply, until symptoms first appear is the
Correct Answer
C. Incubation period
Explanation
The incubation period refers to the time between when a pathogen enters the body and starts multiplying, until the first appearance of symptoms. During this stage, the pathogen is multiplying and spreading within the body, but the individual may not yet experience any noticeable symptoms. This period can vary depending on the specific pathogen and the individual's immune response. Therefore, the incubation period is the correct answer in this case.
9.
Local edema, swollen lymph nodes, fever, soreness, and abscesses are indications of
Correct Answer
B. Inflammation
Explanation
Local edema, swollen lymph nodes, fever, soreness, and abscesses are all common signs and symptoms of inflammation. Inflammation is the body's natural response to injury or infection, and it involves the release of chemicals that cause blood vessels to dilate and become more permeable, leading to the accumulation of fluid in the affected area (edema). Swollen lymph nodes are also a common response to inflammation, as they help to filter out harmful substances. Fever, soreness, and abscesses are all indications of the immune system's efforts to fight off the infection or injury.
10.
The principal government agency responsible for rtacking infectious diseases in the USA is
Correct Answer
A. Centers for Disease Control and Prevention
Explanation
The correct answer is Centers for Disease Control and Prevention. This agency, also known as CDC, is responsible for tracking and preventing the spread of infectious diseases in the United States. They conduct research, provide guidance on disease control measures, and collaborate with other organizations to protect public health. The World Health Organization (WHO) is an international agency that focuses on global health issues. The National Institute of Health (NIH) primarily focuses on medical research and funding. The United States Department of Agriculture (USDA) primarily deals with agricultural and food-related issues. The Infections Control Committee is not a recognized government agency.
11.
A disease that has a steady frequency over time in a population is
Correct Answer
B. Endemic
Explanation
An endemic disease is one that has a steady frequency over time in a population. Unlike an epidemic, which refers to a sudden increase in the number of cases of a disease in a specific area, an endemic disease maintains a consistent level of occurrence within a population. This suggests that the disease is constantly present and does not cause significant fluctuations in its frequency. Therefore, the correct answer is endemic.
12.
The primary, natural habitat of a pathogen where it continues to exist is called the
Correct Answer
D. Reservoir
Explanation
A pathogen's primary, natural habitat where it continues to exist is referred to as a reservoir. This is the place where the pathogen lives and reproduces, allowing it to persist and potentially infect other organisms. Reservoirs can include humans, animals, or environmental sources such as soil or water. By identifying and understanding the reservoirs of a pathogen, it becomes possible to implement effective control measures and prevent the spread of diseases.
13.
An inanimate object that harborts and transmits a pathogen is a
Correct Answer
A. Fomite
Explanation
A fomite is an inanimate object that can harbor and transmit a pathogen. It can include things like doorknobs, cell phones, or clothing. This is different from a carrier, which refers to a person or animal that can carry and transmit a pathogen without showing any symptoms. A vector is an organism, usually an insect or animal, that can transmit a pathogen from one host to another. A reservoir is a place where a pathogen can live and multiply, such as a body of water or an animal. A source refers to the origin or cause of a pathogen.
14.
Nosocomial infections involve all the following except
Correct Answer
A. They are only transmitted by medical personell
Explanation
Nosocomial infections, also known as healthcare-associated infections, are infections that are acquired in a healthcare setting. These infections can be transmitted through various routes, including direct contact with healthcare personnel, contaminated surfaces, equipment, or even through the air. Therefore, the statement "they are only transmitted by medical personnel" is incorrect. Nosocomial infections can involve various body sites, including the urinary tract and surgical incisions, and can be caused by different infectious agents, such as Escherichia coli and Staphylococci. Medical and surgical asepsis practices are implemented to reduce the occurrence of nosocomial infections.
15.
When would Koch's Postulates be utilized
Correct Answer
C. To determine the cause of a new disease in a microbiology lab
Explanation
Koch's Postulates are a set of guidelines used to determine the cause of a disease. They involve isolating and culturing the suspected pathogen, infecting a healthy organism with the cultured pathogen, re-isolating the same pathogen from the newly infected organism, and demonstrating that it is the same as the original pathogen. Therefore, Koch's Postulates would be utilized in a microbiology lab to determine the cause of a new disease.
16.
Components of the first line of defense include all of the following except
Correct Answer
E. pHagocytic white blood cells
Explanation
The first line of defense includes physical barriers and mechanisms that prevent pathogens from entering the body. The tough cell sheet of the upper epidermis of the skin acts as a physical barrier, preventing pathogens from penetrating the skin. Nasal hairs help to filter out and trap pathogens from entering the respiratory system. The flushing action of tears and blinking helps to wash away pathogens from the surface of the eyes. The flushing action of urine helps to eliminate pathogens from the urinary tract. Phagocytic white blood cells, on the other hand, are part of the second line of defense, as they actively engulf and destroy pathogens that have entered the body.
17.
Nonspecific chemical defense include
Correct Answer
D. All of the abvove
Explanation
The correct answer is "all of the above" because nonspecific chemical defense includes lysozyme, lactic acid and electrolytes of sweat, and the skin's acidic pH and fatty acid. These are all examples of chemical substances or conditions that help protect the body from pathogens or harmful substances. Lysozyme is an enzyme that can break down the cell walls of bacteria, lactic acid creates an acidic environment that inhibits the growth of bacteria, electrolytes in sweat can help flush out toxins, and the skin's acidic pH and fatty acid create a barrier against pathogens. Therefore, all of these mechanisms contribute to nonspecific chemical defense.
18.
Which cell type is phagocytotic and can migrate out into body tissues to differentiate inot macrophages
Correct Answer
D. Monocyte
Explanation
Monocytes are a type of white blood cell that are phagocytic, meaning they can engulf and digest foreign particles. They have the ability to migrate out of the bloodstream and into body tissues, where they can differentiate into macrophages. Macrophages play a crucial role in the immune response by engulfing and destroying pathogens, dead cells, and other debris. Therefore, monocytes are the correct answer for this question.
19.
Diapedesis is the
Correct Answer
E. Migration of white blood cells from the blood out to the tissue
Explanation
Diapedesis refers to the migration of white blood cells from the blood out to the tissue. This process is an essential part of the immune response, allowing white blood cells to leave the bloodstream and enter the surrounding tissues to fight off infections or respond to inflammation. During diapedesis, white blood cells squeeze through the walls of blood vessels and move towards the site of infection or tissue damage. This helps to localize the immune response and facilitate the clearance of pathogens or damaged cells.
20.
Plasma cells
Correct Answer
D. Produce and secrete antibodies
Explanation
Plasma cells are a type of white blood cell that play a crucial role in the immune response. They are responsible for producing and secreting antibodies, which are proteins that help to neutralize and eliminate harmful pathogens such as bacteria and viruses. This process is known as humoral immunity. Therefore, the correct answer is that plasma cells produce and secrete antibodies.
21.
The circulating subastances that affect the hypothalmus and initiate fever are
Correct Answer
D. Pyrogens
Explanation
Pyrogens are substances that can affect the hypothalamus and trigger a fever response in the body. They can be either endogenous (produced by the body itself) or exogenous (coming from outside the body). Pyrogens stimulate the release of prostaglandins, which then act on the hypothalamus to increase the body's temperature set-point. This leads to various physiological changes in the body, such as increased metabolism and shivering, in order to raise the body temperature to the new set-point.
22.
Which is incorrect about complement
Correct Answer
B. Only appear in the blood during a response to a pathogen
Explanation
The complement system is a group of proteins in the blood that are involved in the immune response. It is not composed of at least 26 blood proteins, as there are actually over 30 proteins in the complement system. Additionally, the complement system is not only activated during a response to a pathogen, but can also be activated by other stimuli such as immune complexes or certain antibodies. The complement system acts in a cascade reaction, where the activation of one protein leads to the activation of the next in a sequential manner. It involves both classical and alternate pathways for activation. Therefore, the statement that is incorrect is "composed of at least 26 blood proteins".
23.
The membrane attack stage of the complement cascade involves
Correct Answer
C. Ring shaped protein consisting of many C9 proteins, digests holes in bacterial cell membrane and virus envelopes
Explanation
The correct answer is the ring-shaped protein consisting of many C9 proteins, which digests holes in bacterial cell membranes and virus envelopes. This stage is known as the membrane attack stage because it involves the formation of a complex called the membrane attack complex (MAC). The MAC is formed by the sequential binding of C5b, C6, C7, C8, and multiple C9 proteins. Once assembled, the MAC forms a pore in the target cell's membrane, leading to cell lysis and destruction of the pathogen. This process is an essential part of the immune response against bacterial infections and viral infections.
24.
All of the following are types of granulocytes because they have prominent cytoplasmic granules when stained except
Correct Answer
B. Monocytes
Explanation
Monocytes are not considered granulocytes because they lack prominent cytoplasmic granules when stained. Granulocytes, on the other hand, have visible granules in their cytoplasm. Eosinophils, neutrophils, and basophils are all examples of granulocytes as they possess these granules. Therefore, the correct answer is monocytes.
25.
The contribution of B cells is mainly in
Correct Answer
B. Humoral immunity
Explanation
B cells are a type of white blood cell that play a crucial role in humoral immunity. Humoral immunity involves the production of antibodies by B cells in response to the presence of foreign substances, such as pathogens. These antibodies then circulate in the bloodstream and bind to the antigens on the surface of the pathogens, marking them for destruction by other immune cells or neutralizing their harmful effects. Therefore, the main contribution of B cells is in humoral immunity rather than inflammation, complement activity, cell-mediated immunity, or phagocytosis.
26.
The blood cells that particularly target parasitic worms and fungi are
Correct Answer
B. EosinopHils
Explanation
Eosinophils are a type of white blood cell that play a crucial role in the immune response against parasitic worms and fungi. They release toxic substances that help to destroy these pathogens, and also regulate inflammation and allergic reactions. Eosinophils are attracted to sites of infection or inflammation by chemical signals released by the invading parasites or fungi. Once at the site, they can phagocytose (engulf) the pathogens and release their toxic granules to kill them. Therefore, eosinophils are particularly effective in targeting and eliminating parasitic worms and fungi.
27.
Cell surface markers involved in immune reactions
Correct Answer
E. All of the choices are correct.
Explanation
The cell surface markers involved in immune reactions can result from genetic expression, function in the recognition of self molecules, receive and transmit chemical messages among other cells, and aid in cellular development. Therefore, all of the choices are correct.
28.
The major histocompatability complex is
Correct Answer
B. A set of genes that code for MHC cell receptors.
Explanation
The major histocompatibility complex (MHC) is a set of genes that code for MHC cell receptors. MHC cell receptors are proteins found on the surface of cells that play a crucial role in the immune system. These receptors help the immune system identify and distinguish between self and non-self cells, allowing the immune system to recognize and eliminate foreign substances such as pathogens. The MHC genes are highly polymorphic, meaning they exist in many different forms, which contributes to the diversity and effectiveness of the immune response.
29.
Class II MHC genes code for
Correct Answer
D. Receptors located primarily on macrpHages, dendritic cells, and B cells.
Explanation
Class II MHC genes code for receptors located primarily on macrophages, dendritic cells, and B cells. These receptors are involved in the presentation of antigens to helper T cells. Class II MHC molecules are found on the surface of these antigen-presenting cells and bind to antigens that have been internalized and processed. This interaction is crucial for the activation of the immune response and the coordination of the adaptive immune system. Therefore, the answer choice "receptors located primarily on macrophages, dendritic cells, and B cells" is correct.
30.
The monomer subunit of immunoglobulin molecules has all the following except
Correct Answer
D. Four antigen binding sites.
Explanation
Immunoglobulin molecules are made up of two identical heavy polypeptide chains and two identical light polypeptide chains. These chains are held together by disulfide bonds. Each polypeptide chain has a variable and constant region. However, immunoglobulin molecules typically have two antigen binding sites, not four.
31.
Small foreign molecules that are too small by themselves to elict an immune response are termed
Correct Answer
B. Hapten.
Explanation
A small foreign molecule that cannot elicit an immune response on its own is called a hapten. Haptens can become immunogenic when they bind to larger carrier molecules, such as proteins, and form a complex. This complex can then be recognized by the immune system and trigger an immune response. Antigenic determinants refer to specific regions on an antigen that are recognized by antibodies, while antigen binding sites are the regions on antibodies that bind to antigens. The variable region refers to the region of an antibody that is responsible for its specificity in recognizing and binding to antigens.
32.
Superantigens are
Correct Answer
C. Bacterial toxins that activate T cells at a times greater rate then other antigens.
Explanation
Superantigens are bacterial toxins that activate T cells at a much higher rate than other antigens. These toxins are produced by certain bacteria and have the ability to bind to both the T cell receptor and the major histocompatibility complex (MHC) class II molecules on antigen-presenting cells. This binding results in the activation of a large number of T cells, leading to an excessive immune response. Superantigens can cause a variety of symptoms, including fever, inflammation, and tissue damage.
33.
Antigen presenting cells
Correct Answer
E. All of the choices are correct.
Explanation
All of the choices are correct because antigen presenting cells, such as dendritic cells and macrophages, have the ability to engulf and modify antigens to make them more immunogenic. They also hold and present the processed antigens on their cell membrane surface, allowing them to interact with immune cells and initiate an immune response. Therefore, all the statements mentioned in the answer are true and contribute to the role of antigen presenting cells in the immune system.
34.
Mold spores and animal dander are cinsidered to be wich type af allergen?
Correct Answer
B. Inhalant
Explanation
Mold spores and animal dander are considered to be inhalant allergens because they are typically breathed in through the air and can trigger allergic reactions in individuals who are sensitive to them. These allergens can cause symptoms such as sneezing, coughing, wheezing, and itchy eyes when inhaled.
35.
The initial encounter with an allergen is called the
Correct Answer
A. Sensitizing dose
Explanation
The initial encounter with an allergen is called the sensitizing dose because it refers to the first exposure to an allergen that triggers an immune response and sensitizes the body to that specific allergen. This sensitization process can lead to the development of allergies and hypersensitivity reactions upon subsequent exposures to the same allergen. The other options, such as provocative dose, allergic dose, hypersensitivity dose, and desensitizing dose, do not accurately describe the initial encounter with an allergen.
36.
What will be the immediate action of allergen when it enters the body for a second time?
Correct Answer
B. Bonding of allergin to adjacent IgE binding sites on mast cells and basopHils
Explanation
When an allergen enters the body for a second time, it will bond to adjacent IgE binding sites on mast cells and basophils. This bonding triggers the release of chemical mediators, such as histamine and prostaglandins, from these cells. Histamine acts on smooth muscle, causing contraction and symptoms like itching, sneezing, and watery eyes. Prostaglandins cause vasodilation and increased vascular permeability, leading to inflammation and swelling. This immune response is known as degranulation, where the mast cells and basophils release their stored mediators to combat the allergen.
37.
Allergic patients recieving small, controlled injections of specific allergens are undergoing
Correct Answer
A. Desensitization
Explanation
Desensitization is the process of gradually exposing allergic patients to small, controlled injections of specific allergens in order to reduce their sensitivity or allergic reactions to those allergens. This treatment aims to build up the patient's tolerance over time and reduce the severity of their allergic symptoms. It is an effective method for managing allergies and can improve the patient's quality of life by reducing the need for medication and minimizing the risk of severe allergic reactions.
38.
When trafted tissue such as bone marrow contatins passenger lymphocytes what could result
Correct Answer
B. Graft versus host disease
Explanation
When transplanted tissue such as bone marrow contains passenger lymphocytes, it can result in graft versus host disease. This occurs when the immune cells from the donor tissue recognize the recipient's body as foreign and attack it. This immune response can lead to a variety of symptoms and complications, including skin rash, liver damage, and gastrointestinal issues. It is a potentially serious condition that requires medical intervention.
39.
A secondary acquired immunodeficiency is
Correct Answer
A. AIDS
Explanation
A secondary acquired immunodeficiency refers to a condition where the immune system becomes weakened or compromised due to external factors, such as infections or certain medications. AIDS, or Acquired Immunodeficiency Syndrome, is a prime example of a secondary acquired immunodeficiency. It is caused by the human immunodeficiency virus (HIV) which attacks and destroys the immune system, leaving the body vulnerable to various infections and diseases.
40.
The receptors on macrophages that bind to antigen non-specifically and illicit a non specific response and signals to the adaptive immunity response
Correct Answer
B. Toll-like receptor
Explanation
Toll-like receptors are a type of receptor found on macrophages that play a crucial role in the innate immune response. These receptors recognize pathogen-associated molecular patterns (PAMPs) on various microbes, such as bacteria and viruses, and initiate a non-specific immune response. This response includes the production of pro-inflammatory cytokines and the activation of adaptive immunity. Toll-like receptors are essential for the detection of pathogens and the initiation of an immune response, making them the correct answer in this case.
41.
Any heighrtened or inappropriate immune response, an exaggerated, misdeirected expression of immune responses resulting in tissue damage is called a/an
Correct Answer
C. Hypersensitivity
Explanation
Hypersensitivity refers to an exaggerated or inappropriate immune response that leads to tissue damage. It occurs when the immune system overreacts to a harmless substance or allergen, causing symptoms such as inflammation, itching, and swelling. This can happen in conditions like allergies and asthma. Unlike autoimmune diseases, where the immune system mistakenly attacks the body's own cells and tissues, hypersensitivity reactions are triggered by external factors. Immunodeficiency refers to a weakened immune system, transfusion reaction is a response to incompatible blood transfusion, and desensitization is a process used to reduce hypersensitivity reactions.
42.
Transfusion of the wrong blood type can cause
Correct Answer
E. All of these choices
Explanation
Transfusion of the wrong blood type can cause a recipient's antibodies to activate the complement cascade, leading to an attack on the red blood cells (RBCs). This can result in fever and anemia. Additionally, it can lead to systemic shock and kidney failure. Furthermore, the transfusion of the wrong blood type can cause massive hemolysis of the donor's RBCs. Therefore, all of these choices are potential consequences of transfusing the wrong blood type.
43.
Hypersensitivity type II involves
Correct Answer
D. All of the above
Explanation
Hypersensitivity type II involves reactions that lyse foreign cells through the action of antibodies and complement. This type of hypersensitivity is responsible for transfusion reactions, such as those related to ABO blood groups. Therefore, the correct answer is "all of the above."
44.
The immunoglobulins found on the surface of B cells is/are
Correct Answer
C. IgD
Explanation
IgD is found on the surface of B cells.
45.
When antiserum is subjected to electrophoresis, the gamma globulin band contains mostly
Correct Answer
E. IgG
Explanation
When antiserum is subjected to electrophoresis, the gamma globulin band contains mostly IgG. This is because IgG is the main immunoglobulin found in the gamma globulin fraction of serum. IgG is the most abundant antibody in the bloodstream and is responsible for long-term immunity against pathogens.
46.
Which of the following is incorrect about the role of mast cells and basophils in allergies
Correct Answer
D. They are found mainly in the lympH nodes
Explanation
Mast cells and basophils are not mainly found in the lymph nodes. They are found in various tissues throughout the body, including the skin, respiratory tract, and gastrointestinal tract, where they play a crucial role in allergic reactions. When triggered by a specific allergen, they degranulate and release histamine and other inflammatory mediators, leading to allergy symptoms. They carry high numbers of cell receptors that bind to IgE antibodies, and their cytoplasmic secretory vesicles contain physiologically active cytokines.
47.
Cyto T cells
Correct Answer
C. Secrete granzymes and perforins that damage target cells
Explanation
Cyto T cells are a type of cytotoxic T cells that are responsible for directly killing infected or abnormal cells. They do this by secreting granzymes and perforins, which are proteins that cause damage to the target cells. This mechanism helps eliminate cells that pose a threat to the body, such as virus-infected cells or cancer cells. Therefore, the given answer, "secrete granzymes and perforins that damage target cells," is correct as it accurately describes one of the main functions of Cyto T cells.
48.
An example of artifical passive immunity would be
Correct Answer
C. Giving a person immune serum globulins to chickenpox virus afer exposure to the disease
Explanation
Artificial passive immunity refers to providing a person with pre-formed antibodies to a specific pathogen. In this case, giving a person immune serum globulins (which contain antibodies) after exposure to the chickenpox virus provides immediate protection against the disease. This is an example of artificial passive immunity because the person is not producing their own antibodies, but rather receiving them from an external source. The other options mentioned do not involve the direct administration of pre-formed antibodies and therefore do not represent artificial passive immunity.
49.
All of the following characterize the secondary response to an antigen except
Correct Answer
D. It is mostly IgM antibodies that are produced
Explanation
The secondary response to an antigen is characterized by a higher titer of antibody production compared to the primary response, a longer persistence of antibody, and a quicker rate of antibody synthesis. However, it is not mostly IgM antibodies that are produced during the secondary response. Instead, the secondary response is characterized by the production of mainly IgG antibodies. The secondary response is also known as the anamnestic response, as it is a memory response that occurs upon re-exposure to the same antigen.
50.
Hemopoiesis is the
Correct Answer
C. Production of white blood cells, red blood cells, and platelets
Explanation
Hemopoiesis refers to the process of producing new blood cells in the body. This includes the production of white blood cells, red blood cells, and platelets.