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Example Question #2 : Understanding Antibodies And Antigens
Which of the following statements describes the primary role of major histocompatibility complex (MHC) class I molecules?
Activation of the complement cascade
Presentation of short peptide fragments to MHC class II molecules
Presentation of short peptide fragments that are recognized by cytotoxic T-cells
Stimulate production of interferon gamma
Presentation of short peptide fragments that are recognized by cytotoxic T-cells
Major histocompatibility complex (MHC) class I molecules are found on virtually all cells in the body. They function in routine immune monitoring through presentation of short peptide fragments derived from degradation of intracellular proteins contained within the cell. The T-cell receptor on cytotoxic T-cells interacts with MHC class I, and if a foreign pathogen or peptide is presented, the cytotoxic T-cell becomes activated to kill infected cells. The same system also functions for detection of potential cancer cells.
Example Question #3 : Understanding Antibodies And Antigens
An antibody can be best classified as which of the following?
A cell
A virus
A protein
An enzyme
A protein
Antibodies are proteins created by the immune system in order to neutralize foreign objects. An antibody would not be classified as an enzyme because it does not catalyze chemical reactions. When a foreign pathogen enters the body, it will have foreign receptors on its surface. These foreign receptors are known as antigens. When a pathogen is destroyed, immune cells can carry a sample of the antigen to the T-cells for identification. The T-cells help activate B-cells that will synthesize an antibody against the particular antigen. The selected B-cells differentiate into plasma cells and secrete antibody proteins into the blood, which bind the antigens and label the pathogen as foreign. This label attracts other immune cells to attack and destroy the pathogen.
Example Question #3 : Understanding Antibodies And Antigens
Which of the following correctly describes the relationship between an antigen and an antibody?
Antibodies are only made once antigens enter the body
Each antigen has a number of different antibodies that will bind to it
Each antibody recognizes a variety of different antigens
The antigen and antibody are perfectly complimentary to one another
Antibodies attack antigens and neutralize their effects
The antigen and antibody are perfectly complimentary to one another
Antibodies are continuously made in the body in different shapes and forms. They are then sent into the blood stream to test for the presence of compatible antigens. Each antibody can only bind to one antigen, and each antigen can only bind to one antibody. Think of them like a codon-anticodon pair; there is only one possibility for them to form a perfectly complementary pair. Once the correct antibody binds to an antigen, they are tagged and used to stimulate production of more antibodies. The antibodies are only capable of binding and tagging the antigens. Cytotoxic T-cells are then able to recognize antibody binding patterns and actually destroy the infected cell.
Example Question #4 : Understanding Antibodies And Antigens
Major histocompatibility molecules (MHC) are critical for the functioning of the immune system. These proteins are utilized allow for communication between the immune system and the cells. MHC I are utilized to show which cells are in fact part of the body and which are foreign. MHC II are utilized to show the immune system when there is an intruder.
MHC I molecules are derived from chromosome 6. On chromosome 6, there is a specific gene that encodes for the molecule. On the gene, there are 3 locus (A, B, C) which allows for variability in the binding site of the MHC I molecule. The MHC gene is co-dominance and therefore adds to its diversity. During development, the gene is transcribed into MHC I molecules. However, some of these are broken down and react with a particular MHC I molecule. The reaction allows for the MHC I molecule to surface onto the cellular membrane and to self-identify the protein for the cytotoxic T-cell.
After translation, MHC II molecules are transported to the endosome. When a pathogen binds to the proper MHC II binding site, these molecules are then presented to T-Helper cells. In comparison, MHC I molecules interact with endogenous antigens whereas MHC II molecules interact with exogenous antigens.
Based on the passage, where is the interaction between the MHC II molecule and the particular antigen occur?
I. Endoplasmic reticulum
II. Endosome
III. Cytoplasm
II only
III only
I only
I, II, and III
II and III
II only
According to the passage, after the MHC II molecules are fully synthesized in the endoplasmic reticulum, they are transported to the endosome. Foreign molecules are transported into the cell where they are degraded in the endosome as well. From there, the degraded pathogen interact with the MHC II molecule.
Example Question #5 : Understanding Antibodies And Antigens
Major histocompatibility molecules (MHC) are critical for the functioning of the immune system. These proteins are utilized allow for communication between the immune system and the cells. MHC I are utilized to show which cells are in fact part of the body and which are foreign. MHC II are utilized to show the immune system when there is an intruder.
MHC I molecules are derived from chromosome 6. On chromosome 6, there is a specific gene that encodes for the molecule. On the gene, there are 3 locus (A, B, C) which allows for variability in the binding site of the MHC I molecule. The MHC gene is co-dominance and therefore adds to its diversity. During development, the gene is transcribed into MHC I molecules. However, some of these are broken down and react with a particular MHC I molecule. The reaction allows for the MHC I molecule to surface onto the cellular membrane and to self-identify the protein for the cytotoxic T-cell.
After translation, MHC II molecules are transported to the endosome. When a pathogen binds to the proper MHC II binding site, these molecules are then presented to T-Helper cells. In comparison, MHC I molecules interact with endogenous antigens whereas MHC II molecules interact with exogenous antigens.
Based on the passage, where is the interaction between the MHC I molecule and the particular antigen occur?
I. Endoplasmic reticulum
II. Endosome
III. Cytoplasm
I only
II and III
II only
I and III
III only
I only
From the passage, the MHC I molecule's blueprint is on chromosome 6. Therefore, the DNA must have been transcribed in the nucleus then translated in the ribosome. These ribosomes are on the endoplasmic reticulum. While in the endoplasmic reticulum, some of these proteins are degraded and react with a particular MHC I molecule.
Example Question #5 : Understanding Antibodies And Antigens
Major histocompatibility molecules (MHC) are critical for the functioning of the immune system. These proteins are utilized allow for communication between the immune system and the cells. MHC I are utilized to show which cells are in fact part of the body and which are foreign. MHC II are utilized to show the immune system when there is an intruder.
MHC I molecules are derived from chromosome 6. On chromosome 6, there is a specific gene that encodes for the molecule. On the gene, there are 3 locus (A, B, C) which allows for variability in the binding site of the MHC I molecule. The MHC gene is co-dominance and therefore adds to its diversity. During development, the gene is transcribed into MHC I molecules. However, some of these are broken down and react with a particular MHC I molecule. The reaction allows for the MHC I molecule to surface onto the cellular membrane and to self-identify the protein for the cytotoxic T-cell.
After translation, MHC II molecules are transported to the endosome. When a pathogen binds to the proper MHC II binding site, these molecules are then presented to T-Helper cells. In comparison, MHC I molecules interact with endogenous antigens whereas MHC II molecules interact with exogenous antigens.
Based on the passage, which MHC molecule and T-cell is targeted post-organ transplant to avoid rejection of the organ?
MHC I and T-helper cells.
MHC II and cytotoxic T-cells
MHC II and T-helper cells
MHC I and cytotoxic T-cells
None of these
MHC I and cytotoxic T-cells
According to the passage, MHC I and cytotoxic t-cells are responsible for identifying the body's own protein. During organ transplant, foreign MHC I molecules are presented into the body. The host's cytotoxic T-cells will recognize these as foreign and will attack.
Example Question #6 : Understanding Antibodies And Antigens
The chemical reaction in the immune system that protects the body from pathogens is a result of antibodies created by which of the following?
Platelets
White blood cells
Glandular cells
Adipose cells
Red blood cells
White blood cells
White blood cells is the correct answer here. After pathogen has entered the body, the antibodies to combat it are created by B cells that are a part of the white blood cells in the human body.
Example Question #1181 : Ap Biology
Which of the following functions is NOT performed by the lymphatic system?
Elicits an immune response in the presence of an infection
Provides additional oxygen for body tissues
Transports fat digestates and places them into the bloodstream
Returns interstitial fluid to the bloodstream
Provides additional oxygen for body tissues
The lymphatic system is responsible for removing excess fluid from the interstitium and returning it to the bloodstream. The fluid will travel through lymph nodes, which monitor for the presence of microbes in the blood. If microbes are present, the lymph nodes will mount an immune response. The lymphatic system also reroutes fat digestates from the small intestine's capillaries and drains them into the veins of the neck. Lymphatic vessels do not assist in the transfer of oxygen to body tissues.
Example Question #2 : Understanding Other Immune System Components
The lymphatic system is involved in all except which of the following processes?
It is a crucial component of the immune system
Maintain blood volume by reducing fluid loss to the extracellular compartment
Transport red blood cells for destruction in the spleen
Transport fats and fat-soluble vitamins that are absorbed via the digestive tract
Transport red blood cells for destruction in the spleen
Red blood cells generally do not leave the circulatory system; thus there are very few opportunities for lymphatic vessels to pick up red blood cells in the extracellular space.
The lymphatic system plays a key role in transporting immune cells, such as lymphocytes, throughout the body. When fats are emulsified and digested in the small intestine, they are transported into the lymph rather than into the blood. When plasma and fluids leak out of capillaries, the lymphatic system is responsible for collecting and returning these fluids to circulation. A fault in this function of the lymphatic system results in edema.
Example Question #3 : Understanding Other Immune System Components
What is the most likely mechanism a virus could use to evade the immune system that causes periodic outbreaks in an individual over a long period of time?
The virus is actively causing infected cells to secrete factors that suppress the immune system
The virus is continually evolving and manages to vary its antigenic signature so that it can evade detection
The virus manages to attack immune cells needed to control the infection
The virus remains dormant until a stimulus, such as stress or infection with another pathogen, reactivates the virus
The virus remains dormant until a stimulus, such as stress or infection with another pathogen, reactivates the virus
Some viruses evade the immune system using a mechanism known as latency. The virus essentially becomes dormant, usually in cells such as neurons that have few major histocompatibility (MHC) class I molecules. The combination of limited to no active viral replication combined with residence in cells with few MHC lass I molecules allows the virus to evade routine immune monitoring.
When conditions arise, such as fever due to infection caused by another pathogen or emotional stress, the virus can becomes reactivated and can result in an outbreak.
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