1.
The primary immune response is slow, because of the ……..
Correct Answer
D. Absence of both memory B and T cells
Explanation
The primary immune response is slow because of the absence of both memory B and T cells. Memory B and T cells are responsible for recognizing and responding to specific pathogens that the body has encountered before. During a primary immune response, the immune system needs time to identify the pathogen and mount a specific response. Memory cells allow for a faster and more efficient immune response upon subsequent encounters with the same pathogen. Without memory cells, the immune system has to start from scratch each time, leading to a slower response.
2.
The following diagram illustrates both Humoral and Cell mediated immunity. What are the numbers that correspond to the following respectively: B-lymphocyte, interleukin, macrophage, T-cytotoxic, natural killer cell and cytokine?
Correct Answer
B. 4 – 7 – 1 – 5 – 6 – 8
3.
The molecules of the MHC are found in ………
Correct Answer
D. MacropHages and B-lympHocytes
Explanation
The molecules of the MHC (major histocompatibility complex) are found in macrophages and B-lymphocytes. The MHC molecules play a crucial role in the immune response by presenting antigens to T-cells. Macrophages are phagocytic cells that engulf and destroy pathogens, while B-lymphocytes are responsible for producing antibodies. Both of these cell types are involved in the immune response and express MHC molecules on their surface to present antigens to T-cells.
4.
Antigen-MHC complex activates …….
Correct Answer
B. Helper T-cells
Explanation
When an antigen-MHC complex is formed, it is recognized by helper T-cells. Helper T-cells play a crucial role in the immune response by activating other immune cells, such as B-cells and cytotoxic T-cells. They release chemical signals called cytokines that stimulate the production of antibodies by B-cells and enhance the killing ability of cytotoxic T-cells. Therefore, helper T-cells are responsible for coordinating and amplifying the immune response against the antigen.
5.
Which of the following immune cells/molecules are most effective at destroying intracellular pathogens? (Choose all correct answers)
Correct Answer(s)
E. T cytotoxic cells
F. Natural killer cells
Explanation
T cytotoxic cells and natural killer cells are both immune cells that are highly effective at destroying intracellular pathogens. T cytotoxic cells are a type of T cell that directly kills infected cells by releasing toxic substances. Natural killer cells are a type of white blood cell that can recognize and kill infected cells without prior activation. Both of these cells play a crucial role in the immune response against intracellular pathogens.
6.
……… protein inhibits the immune response.
Correct Answer
C. LympHokines
Explanation
Lymphokines are a type of protein that are released by lymphocytes, a type of white blood cell, and they play a key role in regulating the immune response. Lymphokines can either enhance or inhibit the immune response, depending on the specific situation. In this case, the correct answer suggests that lymphokines inhibit the immune response.
7.
Naturally acquired immunity would be mostly acquired through which of the following processes?
Correct Answer
D. Infection with a diseased-causing microorganism followed by recovery.
Explanation
Naturally acquired immunity is the immunity that develops after exposure to a disease-causing microorganism. When a person is infected with a pathogen and recovers from the illness, their immune system develops specific antibodies and memory cells that provide long-lasting protection against future infections. This type of immunity is considered natural because it occurs through natural exposure to the pathogen. Vaccination, drinking colostrum, and natural health may also contribute to immunity, but they are not considered natural processes for acquiring immunity.
8.
Lymphatic cells that induce B-cells to produce antibodies are …..
Correct Answer
A. Helper-T cells
Explanation
Helper-T cells play a crucial role in the immune response by activating B-cells to produce antibodies. These cells recognize antigens presented by B-cells and release cytokines that stimulate B-cell proliferation and differentiation. This interaction between Helper-T cells and B-cells is essential for the production of specific antibodies that can target and neutralize pathogens. Cytotoxic-T cells, Suppressor-T cells, and Natural killer cells have different functions in the immune system and do not directly induce B-cells to produce antibodies.
9.
…….. and ……… cells are responsible for the primary immune response.
Correct Answer
C. B and T
Explanation
B and T cells are responsible for the primary immune response. B cells produce antibodies that target specific antigens, while T cells directly attack infected cells. Together, they coordinate the immune response and help eliminate pathogens from the body.
10.
The following graph illustrates the concentration of three types of T-cells (X), (Y) and (Z) after the entrance of pathogen into the blood of a patient. What are the three types (X), (Y) and (Z) respectively?
Correct Answer
D. Helper – Cytotoxic – Suppressor
Explanation
The correct answer is Helper - Cytotoxic - Suppressor. This is because the graph illustrates the concentration of T-cells in the blood after the entrance of a pathogen. The concentration of Helper T-cells is shown to increase first, followed by an increase in Cytotoxic T-cells, and finally an increase in Suppressor T-cells. Therefore, the correct order of the T-cell types is Helper - Cytotoxic - Suppressor.
11.
The immune cell that is able to respond quickly after any subsequent encounter with the same antigen is the …….
Correct Answer
A. Memory cell
Explanation
Memory cells are immune cells that are formed after an initial encounter with an antigen. These cells "remember" the antigen and can respond quickly and effectively upon subsequent encounters. This rapid response is possible because memory cells have already been sensitized to the antigen and can quickly differentiate into effector cells, such as plasma cells or cytotoxic T cells, to mount a targeted immune response. Basophils are a type of white blood cell involved in allergic reactions, plasma cells are responsible for producing antibodies, and helper T cells play a crucial role in coordinating the immune response but do not possess the ability to quickly respond to subsequent encounters with antigens.
12.
The transfer of antibodies for a certain disease from the blood of the mother to the circulation of the embryo is considered …….
Correct Answer
A. Long lasting protection acquired immunity
Explanation
The transfer of antibodies from the mother's blood to the embryo's circulation is known as passive immunity. This transfer provides the embryo with antibodies that can protect against certain diseases. Acquired immunity refers to the immune response that the body develops after exposure to a specific pathogen, which can provide long-lasting protection. Therefore, the transfer of antibodies from the mother to the embryo through the blood provides long-lasting protection through acquired immunity.
13.
………. cells are responsible for the secondary immune response.
Correct Answer
A. Memory
Explanation
Memory cells are responsible for the secondary immune response. This is because memory cells are a type of immune cell that "remember" a specific pathogen and can quickly mount a response if the same pathogen is encountered again. This secondary immune response is faster and more effective than the primary immune response, which is why memory cells play a crucial role in long-term immunity. Macrophages, monocytes, and plasma are all important components of the immune system, but they do not specifically mediate the secondary immune response like memory cells do.
14.
Helper-T cells cannot recognize the antigens unless it is bind to …..
Correct Answer
B. MHC
Explanation
Helper-T cells cannot recognize antigens unless they are bound to major histocompatibility complex (MHC) molecules. MHC molecules are proteins found on the surface of cells that present antigens to the immune system. When an antigen is bound to an MHC molecule, it can be recognized by a Helper-T cell, which plays a crucial role in coordinating the immune response. Immune globulin is a type of antibody, CD8 is a protein found on cytotoxic T cells, but neither of these are directly involved in antigen recognition by Helper-T cells.
15.
There are …… type(s) of memory cells found in the human body.
Correct Answer
B. Two
Explanation
The correct answer is "Two" because there are two types of memory cells found in the human body. These memory cells are responsible for storing and retrieving information, allowing individuals to remember and recall past experiences and knowledge. The two types of memory cells are short-term memory cells, which hold information temporarily, and long-term memory cells, which store information for a longer period of time.
16.
Which of the following pairs of chemical substances are antagonistic to each other?
Correct Answer
C. Cytokines – LympHokines
Explanation
Cytokines and lymphokines are both types of chemical substances that are involved in regulating the immune response. However, they have different functions and can have opposing effects on the immune system. Cytokines are a broad category of proteins that are involved in cell signaling and communication within the immune system. Lymphokines, on the other hand, are a specific subset of cytokines that are produced by lymphocytes, a type of white blood cell. Lymphokines are involved in the activation and regulation of other immune cells. Therefore, cytokines and lymphokines can have antagonistic effects on each other in terms of immune response regulation.
17.
What will happen if a red blood cell is damaged?
Correct Answer
C. It will be picked up by pHagocytic cells in the liver
18.
The main aim for vaccinating a healthy person with a weak microbe is the …….
Correct Answer
D. Formation of memory cells.
Explanation
When a healthy person is vaccinated with a weak microbe, it stimulates the immune system to produce memory cells. These memory cells "remember" the specific microbe and can mount a rapid and effective immune response if the person is exposed to the actual pathogen in the future. This is the main aim of vaccination - to create a long-lasting immune response that can protect against future infections.
19.
Which statement is not true?
Correct Answer
A. The B cell can bind to extracellular and intracellular antigens.
Explanation
The B cell can only bind to extracellular antigens, not intracellular antigens. Intracellular antigens are recognized by T cells, not B cells.
20.
The third Line of defense includes …….
Correct Answer
C. Immune Response.
Explanation
The third line of defense refers to the immune response, which is a complex system of cells and molecules that work together to identify and eliminate pathogens. This response includes the activation of immune cells such as T cells and B cells, the production of antibodies, and the release of cytokines to coordinate the immune response. The immune response is a crucial defense mechanism against infections and plays a vital role in maintaining overall health and well-being.
21.
Complements do not function unless in the presence of …....
Correct Answer
D. B-cells
Explanation
Complements are a group of proteins that help in the immune response by enhancing the ability of antibodies to eliminate pathogens. However, complements cannot function on their own and require the presence of other immune cells to be activated. Among the options given, B-cells are the most likely to interact with complements. B-cells are responsible for producing antibodies, which can bind to antigens on pathogens and activate complements to destroy the pathogens. Therefore, B-cells are necessary for complements to function effectively in the immune response.
22.
Which of the following enable the immune system to recognize the causing agent of the disease?
Correct Answer
D. Antigens
Explanation
Antigens enable the immune system to recognize the causing agent of the disease. Antigens are molecules that can be found on the surface of pathogens such as bacteria or viruses. When these pathogens enter the body, the immune system recognizes the antigens as foreign and mounts an immune response to eliminate them. This response includes the production of antibodies, which specifically bind to antigens and help to neutralize or eliminate the pathogens. Therefore, antigens play a crucial role in allowing the immune system to identify and respond to the causing agent of the disease.
23.
Among the different ways of defense carried out by the immune system is ……..
Correct Answer
B. Production of antibodies
Explanation
The immune system carries out defense by producing antibodies. Antibodies are proteins that are produced by specialized cells in the immune system called B cells. These antibodies bind to specific foreign substances, such as bacteria or viruses, and help to neutralize or eliminate them from the body. This is an important mechanism of defense in the immune system, as it helps to identify and target harmful invaders. Secretion of toxins, camouflage, and running to escape are not specific mechanisms of defense carried out by the immune system.
24.
Which cells can bind to the CD8 receptors found on the surface of T-suppressor cells?
Correct Answer
D. T-helper, plasma cells and T-cytotoxic
Explanation
T-suppressor cells, also known as CD8+ T cells, play a role in regulating the immune response. They can bind to CD8 receptors found on the surface of T-helper cells, plasma cells, and T-cytotoxic cells. This binding allows T-suppressor cells to interact with these cells and modulate their activity, helping to maintain immune balance and prevent excessive immune responses.
25.
All the following cells secrete interferon protein except …..
Correct Answer
A. Plasma cells
Explanation
Plasma cells are a type of white blood cell that produce and secrete antibodies, not interferon protein. Interferon is a protein that is released by cells in response to viral infection, and it plays a key role in the body's immune response to viruses. T-lymphocytes, macrophages, and viral infected-cells are all capable of secreting interferon protein as part of the immune response. Therefore, the correct answer is plasma cells.
26.
Virual infected cells cannot be destroyed by antibodies produced by plasma cells because ……
Correct Answer
D. The antibodies are relatively large sized molecules that cannot reach the virus inside the cell.
Explanation
Antibodies are proteins produced by plasma cells in response to an infection. They work by binding to specific antigens on the surface of pathogens, such as viruses, and marking them for destruction by the immune system. However, in the case of viral infections, antibodies may not be able to destroy infected cells because they are too large to enter the cells and directly neutralize the virus. Instead, other immune cells, such as cytotoxic T cells, are needed to recognize and eliminate the infected cells. Therefore, the correct answer is that antibodies are relatively large sized molecules that cannot reach the virus inside the cell.
27.
Humoral-mediated immunity defends the body against antigens and pathogens present in(at) ……..
Correct Answer
B. Body fluids
Explanation
Humoral-mediated immunity refers to the immune response that involves the production of antibodies by B cells. These antibodies are then released into the body fluids, such as blood and lymph, to target and neutralize antigens and pathogens. This type of immunity is particularly effective against extracellular pathogens, which are present in body fluids rather than inside cells. Therefore, the correct answer is body fluids.
28.
Which of the following increased by decreasing plasma B cells?
Correct Answer
C. LympHokines
Explanation
Lymphokines increased by decreasing plasma B cells because lymphokines are signaling molecules produced by activated T cells, and they play a role in regulating the immune response. When plasma B cells decrease, it means that there is a decrease in the production of antibodies. Lymphokines are involved in the activation and differentiation of B cells, so when plasma B cells decrease, the production of lymphokines increases to compensate and stimulate the immune response.
29.
Humoral-mediated immunity takes place by means of ….
Correct Answer
C. The antibodies
Explanation
Humoral-mediated immunity is a type of immune response that involves the production and circulation of antibodies. Antibodies are proteins produced by specialized cells called B cells, which are part of the immune system. These antibodies are released into the bloodstream and other body fluids, such as saliva and mucous, to help neutralize and eliminate pathogens. Therefore, the correct answer is "The antibodies" because they play a crucial role in humoral-mediated immunity.
30.
The figure below illustrates the primary and secondary immune responses. At which point do Ts-cells start their action: (A), (B) or (C)?
Correct Answer
B. (B)
Explanation
Ts-cells start their action at point (B).
31.
B-cells after being activated by means of Helper T-cells, they start to ……
Correct Answer
D. Divide and multiply
Explanation
After being activated by Helper T-cells, B-cells undergo a process called clonal expansion, where they divide and multiply rapidly. This allows for the production of a large number of B-cells, which can then differentiate into plasma cells or memory B-cells. The plasma cells are responsible for producing and secreting antibodies, while the memory B-cells help to provide long-term immunity by "remembering" the specific antigen and quickly responding to future infections.
32.
Which sequence is the correct one concerning the immune response?
Correct Answer
D. Activated helper T-cells – interleukin – activated B-cells – plasma cells – antibodies
Explanation
The correct sequence of the immune response is as follows: Activated helper T-cells release interleukin, which activates B-cells. Activated B-cells then differentiate into plasma cells, which produce antibodies. Therefore, the correct sequence is Activated helper T-cells – interleukin – activated B-cells – plasma cells – antibodies.
33.
B-cells adhere to their antigen by ……..
Correct Answer
C. Immune receptors
Explanation
B-cells adhere to their antigen by immune receptors. Immune receptors are proteins on the surface of B-cells that recognize and bind to specific antigens. When an immune receptor on a B-cell binds to its corresponding antigen, it triggers a series of events that activate the B-cell and initiate an immune response. This binding is crucial for the B-cell to recognize and respond to foreign invaders, such as bacteria or viruses, and produce antibodies to neutralize them. MHC (major histocompatibility complex) molecules are involved in presenting antigens to T-cells, not in the direct adherence of B-cells to antigens. CD4 is a protein found on helper T-cells, which plays a role in the immune response, but it is not directly involved in the adherence of B-cells to antigens.
34.
The following diagram illustrates the beginning of an immune response done by T lymphocytes. Which type of T-cells is the one in reaction?
Correct Answer
B. Helper-T
Explanation
The diagram shows the beginning of an immune response, which involves T lymphocytes. Among the given options, Helper-T cells are the ones that play a crucial role in coordinating and regulating the immune response. They help activate other immune cells, such as B cells and cytotoxic T cells, by releasing chemical signals called cytokines. This activation is important for the immune system to effectively eliminate pathogens. Therefore, the correct answer is Helper-T cells.
35.
…….. is an example of specific immunity.
Correct Answer
C. B-lympHocytes
Explanation
B-lymphocytes are an example of specific immunity because they are a type of white blood cell that plays a key role in the adaptive immune response. B-lymphocytes are responsible for producing antibodies, which are proteins that specifically target and neutralize pathogens or foreign substances in the body. This targeted response is characteristic of specific immunity, as it allows the immune system to recognize and respond to specific threats in a highly specific manner.
36.
Activated helper T-cells secrete protein called ……
Correct Answer
A. Interleukins
Explanation
Activated helper T-cells secrete proteins called interleukins. Interleukins are a group of cytokines that act as signaling molecules between immune cells. They play a crucial role in regulating the immune response by promoting the activation, proliferation, and differentiation of other immune cells. Interleukins also help in coordinating the immune response by mediating communication between different types of immune cells. Therefore, the secretion of interleukins by activated helper T-cells is essential for the proper functioning of the immune system.
37.
One of the following is not a function of cytokines ……
Correct Answer
B. Stimulate the plasma cells to produce antibodies
Explanation
Cytokines are small proteins that play a crucial role in cell signaling during immune responses. They are involved in various functions such as attracting immune cells to the site of infection, activating immune cells like natural killer cells and macrophages, and coordinating the immune response. However, stimulating plasma cells to produce antibodies is not a function of cytokines. Plasma cells are activated by B lymphocytes through a process called antigen presentation and T cell help. Cytokines may indirectly support this process by promoting the activation and proliferation of B lymphocytes, but they do not directly stimulate plasma cells to produce antibodies.
38.
The cell which divides into two types of cells is ….
Correct Answer
B. B-lympHocyte
Explanation
B-lymphocytes are a type of white blood cell that are responsible for producing antibodies. They have the ability to divide and differentiate into two types of cells: plasma cells, which produce and secrete antibodies, and memory cells, which "remember" a specific pathogen and provide long-term immunity. This division and differentiation process allows B-lymphocytes to effectively respond to and eliminate infections in the body. Natural killer cells, monocytes, and macrophages do not undergo this type of division and differentiation.
39.
Which cells can bind to the CD4 receptors found on the surface of T-helper cells?
Correct Answer
A. MacropHage and B-cells
Explanation
Macrophages and B-cells are capable of binding to the CD4 receptors found on the surface of T-helper cells. This binding is important for the activation of T-helper cells and the initiation of an immune response. Macrophages are antigen-presenting cells that can present antigens to T-helper cells, while B-cells can interact with T-helper cells to receive signals for antibody production. Therefore, both macrophages and B-cells play crucial roles in the immune response by binding to CD4 receptors on T-helper cells.
40.
Tears possess a defense mechanism that protects the body, because they contain …..
Correct Answer
B. Antimicrobial substances
Explanation
Tears possess a defense mechanism that protects the body because they contain antimicrobial substances. These substances help to kill or inhibit the growth of microorganisms, such as bacteria, on the surface of the eye. This defense mechanism helps to prevent eye infections and maintain the overall health of the eye.
41.
Fragments of antigens will bind to a protein called ……. Inside the macrophage.
Correct Answer
B. Major histocompatibility complex
Explanation
Fragments of antigens will bind to a protein called Major histocompatibility complex inside the macrophage. The Major histocompatibility complex is responsible for presenting the antigen fragments to T cells, which triggers an immune response. This process helps the immune system identify and eliminate foreign substances in the body.
42.
What triggers the activation of a T-helper cell?
Correct Answer
A. Binding to an antigen-presenting cell with a specific processed antigen on its surface
Explanation
T-helper cells are activated when they bind to an antigen-presenting cell that displays a specific processed antigen on its surface. This interaction is crucial for the immune response as it allows the T-helper cell to recognize the antigen and initiate a cascade of immune reactions. The other options, such as bacterial toxins, mast cells, complement proteins, and extracellular antigens, are not directly involved in the activation of T-helper cells.
43.
Which of the following is not an example of innate immunity?
Correct Answer
B. Antibodies
Explanation
Antibodies are not an example of innate immunity because they are produced by the adaptive immune system in response to specific pathogens. Innate immunity, on the other hand, is the body's first line of defense and includes physical barriers like mucus membranes, as well as non-specific mechanisms like phagocytosis and interferon production.
44.
A doctor vaccinates a child against measles. A few weeks after the vaccination, the child becomes infected with measles viruses from another person. The graph shows the number of measles antibodies in the child’s blood from before the vaccination until after the infection. Describe the difference in the immune response after infection compared with after vaccination.
Correct Answer
A. After vaccination some lympHocytes develop into memory cells but after infection the required lympHocytes are able to reproduce rapidly
Explanation
After vaccination, some lymphocytes develop into memory cells. This means that the body has a reserve of immune cells that can recognize and respond quickly to future infections. However, after infection, the required lymphocytes are able to reproduce rapidly. This means that the body can produce a large number of immune cells to fight the infection. So, the main difference in the immune response after infection compared with after vaccination is that vaccination provides long-term immunity through memory cells, while infection triggers a rapid reproduction of lymphocytes.
45.
The adaptive immunity that involves the production of antibodies for the clearance of antigen is called ……..
Correct Answer
C. Humoral Immunity
Explanation
Humoral immunity is the correct answer because it refers to the adaptive immune response that involves the production of antibodies by B cells. These antibodies are produced in response to the presence of antigens and are responsible for neutralizing and eliminating the antigens from the body. This type of immunity is called "humoral" because it involves the presence of antibodies in the body fluids, such as blood and lymph. The production of antibodies is a key mechanism for the clearance of antigens in the immune system.
46.
How does the nonspecific immune response compare to the specific response to antigens?
Correct Answer
A. The nonspecific response is faster than the specific immune response.
Explanation
The nonspecific immune response refers to the general defense mechanisms that the body has in place to prevent and fight against infections, such as inflammation and fever. These responses are not specific to a particular antigen and can be activated quickly. On the other hand, the specific immune response is a targeted response that is tailored to a specific antigen, such as a virus or bacteria. This response takes longer to develop as it involves the production of specific antibodies and immune cells. Therefore, the nonspecific immune response is faster than the specific immune response.
47.
Antibody functions as the effector of the humoral response by antigen binding and neutralizing it.
The antigen can be eliminated by ........
Correct Answer
D. All of the above
Explanation
Antibodies can eliminate antigens by facilitating their uptake by phagocytes, activating complements and inducing cell lysis, and preventing their binding and attachment to host cells. By performing all of these functions, antibodies effectively neutralize antigens and aid in their elimination from the body.
48.
What is a difference between cell-mediated and humoral (antibody-mediated) immunity?
Correct Answer
E. Humoral immunity responds to extracellular pathogens, while cell-mediated immunity responds to intracellular pathogens.
Explanation
The correct answer states that humoral immunity responds to extracellular pathogens, while cell-mediated immunity responds to intracellular pathogens. This means that humoral immunity is responsible for targeting pathogens that are outside of the body's cells, such as bacteria and viruses in the bloodstream or tissues. On the other hand, cell-mediated immunity is involved in targeting pathogens that have infected the body's cells, such as viruses that have entered and replicated within a host cell. This differentiation in the type of pathogens targeted is a key difference between the two types of immunity.
49.
Which of the following is NOT a major feature (characteristic) of the adaptive immune system?
Correct Answer
C. Inflammatory response
Explanation
The inflammatory response is not a major feature of the adaptive immune system. The adaptive immune system is characterized by specificity, diversity, and the presence of memory cells. Specificity refers to the ability of the immune system to recognize and target specific pathogens. Diversity refers to the wide range of different antigens that the immune system can recognize. Memory cells are responsible for the immune system's ability to remember and mount a faster and stronger response upon subsequent exposure to a pathogen. The inflammatory response, on the other hand, is a major feature of the innate immune system, which is the first line of defense against pathogens.
50.
The figure shows changes in antibody concentrations in the blood after exposure to antigens A and B. How does the time lag between initiating a primary immune response to antigen A and its peak approximately compare to the time lag of the secondary immune response to antigen A?
Correct Answer
C. The primary response takes approximately twice as long to peak as the secondary response.
Explanation
The figure shows that the peak of the primary immune response to antigen A occurs at a later time compared to the peak of the secondary immune response to antigen A. Therefore, the primary response takes approximately twice as long to peak as the secondary response.