In: Biology
Q1) Which of the following statements about the humoral immune response is true
A |
The humoral immune response involves the production of interleukin-2 to stimulate T-cell proliferation. |
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B |
The humoral immune response does not involve clonal selection. |
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C |
The humoral immune response defends against bacteria and viruses by activating T cells. |
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D |
The humoral immune response is the result of macrophages producing antibodies. |
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E |
The humoral immune response defends primarily against pathogens present in body fluids. |
Q2) Which one of the following statements is FALSE?
A |
An antibody usually recognizes and binds to an epitope on an antigen. |
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B |
An individual B-cell produces antibodies that bind to a number of different epitopes. |
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C |
Most antigenic determinants are portions of proteins or glycoproteins on the surfaces of foreign cells. |
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D |
A pathogen (microbe) usually has several different antigenic determinants. |
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E |
A single pathogen may stimulate the immune system to make several distinct antibodies to it. |
Q3) Which two factors help establish the resting potential?
A |
Diffusion of potassium ions out of the cell and diffusion of anions into the cell. |
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B |
Sodium-potassium pump and voltage-gated sodium channels. |
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C |
Sodium-potassium pump and diffusion of potassium ions out of the cell. |
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D |
Diffusion of sodium ions into the cell and diffusion of potassium ions out of the cell. |
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E |
Sodium-potassium pump and diffusion of sodium ions into the cell. |
Answer:
1.(E)The humoral immune response defends primarily against pathogens present in body fluids.
T cell is very specific in nature and is a part of cell mediated immunity. So where there is mention of T cells, those options are wrong for humoral immunity.That eliminates option A and C. The macrophages are also involved in cell mediated immunity, so option D is also right. Upon activation by the antigen, the Bcells go under clonal selection and differentiate into antibody producing Bcells and plasma. So the only correct option is E .
2.(B) An individual Bcell produces antibodies that bind to a number of different epitopes.
When a pathogen enters the body, it's glycoprotein act as antigens to the body. Different glycoproteins may act as different antigens. For these different antigens different antibodies are prepared by the body to counter it.So one pathogen may induce various immune response and hence various antibodies.
So the antigens are very specific to the epitope they bind and hence one antibody doesn't bind to multiple epitopes.
Please post the questions separately to know all the answers. I couldn't do it due to the time consent.
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