1.
Which of the following arguments makes the most sense?
Correct Answer
B. Parasites tend to feed off of their host little by little
Explanation
The answer "parasites tend to feed off of their host little by little" makes the most sense because it aligns with the concept of parasites gradually consuming resources from their host without killing it immediately. This behavior allows the parasite to sustain itself for a longer period of time, maximizing its chances of survival. The other options either do not accurately describe the relationship between parasites and hosts or make generalizations that may not apply to all parasites.
2.
Which of the following is not one of Koch's Postulates?
Correct Answer
A. Grow the bacterium in pure culture to see what antibiotic is most effective
Explanation
The given answer, "grow the bacterium in pure culture to see what antibiotic is most effective," is not one of Koch's Postulates. Koch's Postulates are a set of criteria used to establish a causal relationship between a microorganism and a disease. The correct postulates are: (1) isolate the microorganism from the diseased host, (2) grow the microorganism in pure culture, (3) inoculate a healthy host with the cultured microorganism, (4) re-isolate the same microorganism from the newly infected host. The given answer does not fit into any of these postulates and is therefore not one of Koch's Postulates.
3.
Why cant viral disease be studied using kochs postulates?
Correct Answer
E. A and b
Explanation
Viral diseases cannot be studied using Koch's postulates because viruses have very specific hosts and cannot be grown in pure culture. Koch's postulates require the ability to isolate and grow the pathogen in pure culture, which is not possible with viruses. Additionally, viruses have a narrow host range, meaning they can only infect specific species or cell types, making it difficult to study their effects in a controlled experimental setting. Therefore, both options "a" and "b" are correct explanations for why viral diseases cannot be studied using Koch's postulates.
4.
Nonsocomial
Correct Answer
A. Spread while staying at hospital
Explanation
The term "nosocomial" refers to infections that are acquired in a hospital or healthcare setting. These infections are typically spread from person to person within the hospital environment. Therefore, the correct answer "spread while staying at hospital" accurately describes the transmission of the disease within the hospital setting.
5.
Reservoir
Correct Answer
C. Source of infection in the enviroment
Explanation
A reservoir refers to a source of infection in the environment. It is an inanimate object that can harbor and transmit disease-causing organisms. This means that even though someone may have recovered from a disease, they can still spread it to others through contact with the reservoir. In the context of a disease outbreak, identifying and controlling these sources of infection is crucial in preventing further spread of the disease.
6.
HAI
Correct Answer
D. Spread while staying at hospital
Explanation
The given answer, "spread while staying at hospital," suggests that the transmission of the disease occurs within the hospital setting. This means that individuals who are already hospitalized can further spread the infection to other patients or healthcare workers. This can happen due to various factors such as poor hygiene practices, contaminated medical equipment, or close proximity between infected and susceptible individuals. The answer implies that the spread of the disease is specifically linked to hospital-associated infections, rather than being caused by other factors like the degree of pathogenicity, a worldwide outbreak, or a vector of infection.
7.
epidemic
Correct Answer
B. Disease of outbreak
Explanation
The correct answer is "disease of outbreak" because an epidemic refers to a sudden increase in the number of cases of a particular disease in a specific population or geographic area. It is characterized by the rapid spread of the disease and affects a larger number of people than usual. Therefore, an epidemic can be described as a disease of outbreak.
8.
Pandemic
Correct Answer
A. Worldwide outbreak of disease
Explanation
A pandemic refers to a worldwide outbreak of a disease, affecting a large number of people across different countries or continents. It is characterized by the rapid spread of the disease, causing significant illness and sometimes death. The term "pandemic" is used when a disease surpasses the epidemic level and becomes a global health concern. Therefore, the answer "worldwide outbreak of disease" accurately describes the concept of a pandemic.
9.
Communicable
Correct Answer
B. Disease that is spread by direct contact
Explanation
The term "communicable" refers to a disease that can be transmitted from one person to another through direct contact. This means that the disease can spread through physical touch, such as shaking hands or sharing personal items. Unlike diseases that are spread through inanimate objects, like contaminated surfaces or airborne particles, communicable diseases require direct contact with an infected individual for transmission. Therefore, the correct answer is "disease that is spread by direct contact."
10.
Carrier
Correct Answer
C. Someone recovering from disease but can still spread it
Explanation
A carrier is someone who has recovered from a disease but still has the ability to spread it to others. Even though they may not show any symptoms, they still carry the infectious agent and can transmit it to others. This is why carriers are considered a source of infection, as they can unknowingly pass on the disease to others. In the context of a hospital, where there may be vulnerable individuals, it is important to identify and isolate carriers to prevent further transmission of the disease.
11.
Contagious
Correct Answer
B. Source of infection in the environment
Explanation
The term "source of infection in the environment" refers to an object or substance that can transmit disease-causing pathogens to individuals. In the context of the given options, it is the most suitable explanation for the term "contagious." This suggests that the disease can be contracted from an inanimate object present in the environment, indicating that the disease outbreak is caused by the spread of the disease through contact with contaminated objects or surfaces.
12.
Fomite
Correct Answer
A. Inanimate object
Explanation
The term "fomite" refers to an inanimate object that can carry and transmit infectious agents. It can include things like doorknobs, phones, or clothing. These objects can become contaminated with pathogens and act as a source of infection when touched or used by others. Therefore, the correct answer is "inanimate object," as it accurately describes the role of a fomite in spreading infections.
13.
virluence
Correct Answer
C. Degree of pathogenicity
Explanation
The term "degree of pathogenicity" refers to the measure of how likely a disease-causing agent is to cause illness in an infected individual. It indicates the severity and virulence of the pathogen in causing disease. This term is unrelated to the other options provided, which include "worldwide outbreak of disease," "disease outbreak," and "inanimate object." Therefore, the correct answer is "degree of pathogenicity."
14.
Put the stage of infection in order from the begining to the end
a. acme period
b. incubation period
c. prodromal phase
d. period of convalescence
e. period of decline
Correct Answer
C. Bcaed
Explanation
The correct order of the stages of infection is as follows:
b. incubation period - This is the period between the initial infection and the appearance of symptoms. The pathogen is multiplying within the body during this stage.
c. prodromal phase - This is the stage where the initial symptoms start to appear. The symptoms may be mild, but they indicate that the infection is progressing.
a. acme period - This is the stage where the infection is at its peak. The symptoms are usually the most severe during this stage.
e. period of decline - In this stage, the symptoms start to lessen, and the infection begins to subside. The body's immune response is effectively fighting off the infection.
d. period of convalescence - This is the final stage where the body is recovering from the infection. The symptoms have disappeared, and the individual is returning to their normal state of health.
15.
how does the dose of a particular infectious agent affect the disease?
Correct Answer
F. C and d
Explanation
Different doses of a particular infectious agent can have different effects in some diseases. This means that the severity of the disease can vary depending on the dose of the infectious agent. Additionally, smaller doses can cause subclinical infections, which means that the person may not show any symptoms of the disease but can still be infected.
16.
Toxic shock syndrome is a result of a type 1 exotoxin. Which best describes type 1 exotoxins?
Correct Answer
C. The cause major over reaction of immune system
Explanation
Type 1 exotoxins are toxins that cause a major overreaction of the immune system. This means that when these toxins are released by bacteria, they trigger an excessive response from the immune system, leading to an exaggerated inflammatory response. This can result in symptoms such as fever, rash, and organ dysfunction, which are characteristic of toxic shock syndrome.
17.
Gas gangrene is a result of type 2 exotoxins. Which of the following describes this class of toxins?
Correct Answer
D. They damage cell membranes
Explanation
Type 2 exotoxins are toxins that damage cell membranes. This means that they disrupt the integrity and function of cell membranes, leading to cell death and tissue damage. Gas gangrene, a condition caused by certain bacteria, is a result of the action of these type 2 exotoxins on cell membranes. The other options listed in the question, such as being 2 part toxins or being the outer LPS layer of gram negative bacteria, do not accurately describe type 2 exotoxins.
18.
Involves heat, redness, swelling, and pain
Correct Answer
A. Inflammation
Explanation
Inflammation is a localized response to tissue injury or infection, characterized by heat, redness, swelling, and pain. It is a natural defense mechanism of the body to protect and heal damaged tissues. When tissues are injured, immune cells release chemical signals that attract other immune cells to the site of injury. These immune cells release additional chemicals that increase blood flow to the area, causing redness and heat. They also cause blood vessels to become more permeable, allowing fluid and immune cells to move into the tissues, leading to swelling. The release of chemicals also stimulates nerve endings, causing pain. Overall, inflammation helps to remove harmful substances, repair damaged tissues, and initiate the healing process.
19.
Antibodies
Correct Answer
C. Humoral response
Explanation
The humoral response is the immune response mediated by antibodies, which are produced by B cells. This response is primarily targeted against extracellular pathogens and toxins. Antibodies bind to antigens on the surface of pathogens, neutralizing them and marking them for destruction by other immune cells. This response is characterized by the production of specific antibodies that can provide long-lasting immunity to future infections. In contrast, the cell-mediated response involves the activation of T cells to directly attack infected cells. The complement cascade is a series of proteins that enhance the immune response by promoting inflammation and the destruction of pathogens. Therefore, the humoral response is the most appropriate answer in this context.
20.
Destroying cancer cells
Correct Answer
B. Cell mediated response
Explanation
The cell mediated response refers to the immune response that involves the activation of T cells, which are responsible for recognizing and destroying infected or cancerous cells. This response is characterized by the release of cytokines and the recruitment of other immune cells to the site of infection or tumor. Unlike the humoral response, which involves the production of antibodies by B cells, the cell mediated response directly targets and eliminates the cancer cells or infected cells. Therefore, the cell mediated response is the most appropriate explanation for destroying cancer cells.
21.
Calls in macrophages through opsinization
Correct Answer
C. Humoral response
Explanation
The humoral response is the correct answer because it involves the production of antibodies by B cells in response to an antigen. Antibodies can bind to antigens, including those on the surface of pathogens, and mark them for destruction by other immune cells. This response is called opsonization, which enhances the phagocytosis of pathogens by macrophages. In contrast, cell-mediated responses involve the activation of T cells to directly attack infected cells, while the complement cascade is a series of proteins that can enhance the immune response but is not specific to opsonization.
22.
Series in protein that result in cell death or opsonization
Correct Answer
D. Complement cascade
Explanation
The complement cascade is a series of reactions in the immune system that play a crucial role in inflammation, cell-mediated response, humoral response, and opsonization. It involves a group of proteins that work together to tag pathogens for destruction, recruit immune cells to the site of infection, and enhance the effectiveness of antibodies. Activation of the complement cascade can lead to cell death of pathogens, as well as the activation of other immune responses.
23.
Responds to cellular damage and injury
Correct Answer
A. Inflammation
Explanation
Inflammation is the body's response to cellular damage and injury. It is a complex process involving various immune cells and chemical mediators. When cells are damaged or injured, the body releases inflammatory mediators such as histamine, prostaglandins, and cytokines. These mediators cause blood vessels to dilate, leading to increased blood flow to the affected area. They also increase the permeability of blood vessels, allowing immune cells to migrate to the site of injury. Inflammation helps to remove damaged cells, initiate tissue repair, and defend against potential pathogens.
24.
Plamsa cells and memory cells
Correct Answer
C. Humoral response
Explanation
The humoral response is one of the two main types of immune responses, along with the cell-mediated response. It involves the activation of B cells, which produce antibodies that circulate in the blood and lymphatic system. These antibodies can recognize and bind to specific antigens, marking them for destruction by other immune cells or neutralizing their effects. The humoral response is particularly effective against extracellular pathogens, such as bacteria and viruses that are circulating in the body fluids. This response is characterized by the production of plasma cells, which are specialized B cells that secrete large amounts of antibodies, and memory cells, which provide long-term immunity.
25.
Helper t cells and killer t cells
Correct Answer
B. Cell mediated response
Explanation
The cell-mediated response is a type of immune response that involves the activation of helper T cells and killer T cells. These cells play a crucial role in defending the body against intracellular pathogens, such as viruses and certain bacteria. Helper T cells recognize antigens presented by antigen-presenting cells and release cytokines to activate killer T cells. Killer T cells, in turn, directly attack and destroy infected cells. This response is important in eliminating infected cells and controlling the spread of pathogens.
26.
Causes dilation of capillaries
Correct Answer
A. Inflammation
Explanation
Inflammation is the correct answer because it causes dilation of capillaries. During inflammation, the body's immune response is activated, leading to an increase in blood flow to the affected area. This increase in blood flow causes the capillaries to dilate, allowing more immune cells and substances to reach the site of inflammation. This helps in fighting off any pathogens or foreign substances that may be present, and also facilitates the delivery of nutrients and oxygen to the area for tissue repair and healing.
27.
Phagocytosis is the process where
Correct Answer
D. pHagocytosis involves all the above
Explanation
Phagocytosis is a process where macrophages, which are immune cells, engulf and remove foreign particles and infected cells from the body. Additionally, invading pathogens are tagged and broken down during phagocytosis. Bacteria can also be broken down through phagocytosis, and their antigens are used to stimulate an immune response. Therefore, phagocytosis involves all of the mentioned processes, making the given answer correct.
28.
Sebum
Correct Answer
B. Oily goo on the skin
Explanation
Sebum is an oily substance produced by the sebaceous glands in the skin. It acts as a natural moisturizer and lubricant, keeping the skin hydrated and protected. The presence of sebum creates a slightly acidic environment on the skin, which lowers its pH. This acidic pH makes it unfavorable for the growth of most bacteria, as they thrive in a more alkaline environment. Therefore, the statement "oily goo on the skin" is an accurate description of sebum.
29.
Lysozyme
Correct Answer
A. Kills cells infected with virus
Explanation
Lysozyme is an enzyme that is present in bodily fluids like tears and saliva. It plays a role in the immune system by breaking down the cell walls of certain bacteria, including gram-positive bacteria. However, it is primarily known for its ability to kill cells infected with viruses. This is because lysozyme can disrupt the viral envelope, which is a protective layer surrounding the virus. By destroying the envelope, lysozyme renders the virus unable to infect other cells, effectively killing it.
30.
Mucous
Correct Answer
B. Sticky substance that traps organisms trying to enter the body
Explanation
The correct answer is "sticky substance that traps organisms trying to enter the body." Mucous is a substance secreted by the body's mucous membranes, such as those in the respiratory and digestive systems. It acts as a protective barrier by trapping foreign particles, such as dust, bacteria, and viruses, preventing them from entering the body and causing harm. Mucous also contains antibodies and enzymes that help to neutralize and eliminate these trapped organisms.
31.
Acids
Correct Answer
D. Lowers pH making it not suitable for most bacteria
Explanation
Acids have the ability to lower the pH of their surroundings, which creates an acidic environment. This acidic environment is not suitable for most bacteria to survive and grow in. Bacteria typically thrive in a neutral or slightly alkaline pH. Therefore, the statement that acids lower the pH, making it not suitable for most bacteria, is a correct explanation.
32.
interferon
Correct Answer
A. Kills gram positive bacteria
33.
Pyrogens
Correct Answer
B. Stimulates fever
Explanation
Pyrogens are substances that stimulate the body to increase its temperature, resulting in fever. When pyrogens are present in the body, they trigger the release of certain chemicals that act on the hypothalamus, the part of the brain responsible for regulating body temperature. This causes the body to raise its temperature in an attempt to fight off infections or other harmful agents. Therefore, the correct answer is "stimulates fever."
34.
Which of the following is not true of antigens?
Correct Answer
A. They are made of lipids and dna
Explanation
The statement "they are made of lipids and DNA" is not true of antigens. Antigens are usually proteins or polysaccharides that can stimulate the immune system. Lipids and DNA are not typically considered antigens.
35.
Epitopes are
Correct Answer
B. Part of the antigen to which antibody binds
Explanation
Epitopes are specific parts of an antigen that are reactive and can bind to antibodies. When an antigen enters the body, antibodies are produced to specifically target and bind to these epitopes. This binding is essential for the immune system to recognize and neutralize the antigen. Therefore, the correct answer is "part of the antigen to which antibody binds."
36.
The MHC proteins of cells
Correct Answer
E. A and b
Explanation
The MHC proteins of cells play a crucial role in the immune system. They display antigens of self and non-self origin, allowing the immune system to distinguish between the body's own cells and foreign cells. Additionally, MHC proteins interact with both B cells and T cells, which are key players in the immune response. Therefore, the correct answer is a and b.
37.
Antiboidies attaching to antigens during the course of an infection is an example of
Correct Answer
A. Active natural immunity
Explanation
During the course of an infection, antibodies attach to antigens to neutralize them and prevent further harm to the body. This process is an example of active natural immunity because the immune system of the body is actively producing antibodies in response to the infection. Active natural immunity is acquired through natural exposure to pathogens and the subsequent immune response, leading to the development of memory cells that provide long-term protection against future infections.
38.
Pentameric antibody
Correct Answer
D. IgM
Explanation
IgM is the correct answer because it is the first antibody produced in response to an infection. It is a pentameric antibody, meaning it is made up of five individual antibody molecules. IgM is primarily found in the bloodstream and is responsible for activating the complement system to help eliminate pathogens. It is also the largest antibody and has a high binding avidity, allowing it to effectively neutralize and clear pathogens from the body.
39.
First antibody to be produced
Correct Answer
C. IgM
Explanation
IgM is the first antibody to be produced during an immune response. It is primarily found in the bloodstream and plays a crucial role in the early stages of an infection. IgM is responsible for neutralizing pathogens and activating other components of the immune system. It is also the largest antibody and is effective at agglutinating (clumping together) antigens. Overall, IgM is an important component of the body's defense against pathogens.
40.
Found in mother milk
Correct Answer
A. IgA
Explanation
IgA is found in mother's milk.
41.
Found bound to mast cells and b cells
Correct Answer
C. IgD
Explanation
IgD is found bound to mast cells and B cells.
42.
The major circulating antibody
Correct Answer
B. IgG
Explanation
IgG is the major circulating antibody in the body. It is the most abundant immunoglobulin in the bloodstream and is responsible for long-term immunity. IgG antibodies are able to cross the placenta, providing passive immunity to the fetus during pregnancy. They are also involved in opsonization, neutralization of toxins and viruses, and activation of the complement system. IgG is produced in response to both primary and secondary immune responses and plays a crucial role in protecting against bacterial and viral infections.
43.
Associated with mucous membrane
Correct Answer
A. IgA
Explanation
IgA is the correct answer because it is the immunoglobulin that is primarily associated with mucous membranes. IgA is found in high concentrations in saliva, tears, and other bodily secretions, where it plays a crucial role in defending against pathogens that enter the body through these routes. It acts as the first line of defense by neutralizing and preventing the attachment of pathogens to the mucosal surfaces, thus preventing infections. IgA is also important in providing immunity to newborns through breast milk, as it helps protect their gastrointestinal tract from harmful bacteria and viruses.
44.
Responsible for allergic responses
Correct Answer
E. IgE
Explanation
IgE is responsible for allergic responses. IgE is an antibody that plays a crucial role in triggering allergic reactions. When a person is exposed to an allergen, such as pollen or pet dander, their immune system produces IgE antibodies. These antibodies then bind to mast cells and basophils, which are immune cells found in tissues throughout the body. When the person is exposed to the allergen again, it binds to the IgE antibodies on the mast cells and basophils, causing the release of histamine and other chemicals that lead to allergic symptoms like itching, sneezing, and inflammation.
45.
Able to cross placenta
Correct Answer
D. IgG
Explanation
IgG is the correct answer because it is the only immunoglobulin that is able to cross the placenta. This allows it to provide passive immunity to the fetus during pregnancy, protecting the baby from certain infections. IgA, IgM, IgD, and IgE do not have the ability to cross the placenta.
46.
Found in tears
Correct Answer
A. IgA
Explanation
IgA is the correct answer because it is found in tears. IgA is an immunoglobulin that is primarily found in mucosal secretions, including tears, saliva, and mucus. It plays a crucial role in protecting the mucosal surfaces of the body from infections by trapping pathogens and preventing their entry into the body. IgD, IgM, IgG, and IgE are also immunoglobulins, but they are not specifically found in tears.
47.
Protects the fetus
Correct Answer
A. IgA
Explanation
IgA is the correct answer because it is the type of antibody that is primarily found in mucosal secretions, such as saliva, tears, and breast milk. It plays a crucial role in protecting the fetus by providing passive immunity through the placenta and breast milk. IgA helps to prevent pathogens from entering the body through these mucosal surfaces, thus protecting the fetus from infections.
48.
Protects the newborn
Correct Answer
B. IgG
Explanation
IgG is the correct answer because it is the only antibody that can cross the placenta from the mother to the fetus, providing passive immunity to the newborn. This antibody plays a crucial role in protecting the newborn from infections during the first few months of life. IgA, IgM, IgD, and IgE are not able to cross the placenta and therefore do not provide this level of protection to the newborn.
49.
What is the difference between natural and artificial immunity
Correct Answer
C. Artificial immunity is given to you as in vaccine or immune serum
Explanation
The given answer correctly explains that artificial immunity is acquired through vaccination or the administration of immune serum. This type of immunity is intentionally induced by introducing specific antigens into the body to stimulate an immune response. On the other hand, natural immunity is obtained through the course of infection or vaccination, meaning that the body develops immunity naturally in response to exposure to pathogens. The explanation provided is clear and concise, highlighting the distinction between natural and artificial immunity.
50.
Herd immunity relies on
Correct Answer
D. All the above
Explanation
Herd immunity relies on a combination of factors. Firstly, a high level of efficacy of the vaccine is necessary to ensure that a significant portion of the vaccinated population develops immunity. Additionally, a large number of people need to be vaccinated in order to achieve herd immunity, as this reduces the overall number of susceptible individuals in a community. Lastly, people living close together can facilitate the spread of diseases, making it easier for infections to circulate within a population. Therefore, all of the above factors contribute to the effectiveness of herd immunity.