This set of Life Sciences Multiple Choice Questions & Answers (MCQs) focuses on “B-Cell”.
1. Which of the following is responsible for B-cell activation?
Explanation: The activation of mature B-cell is done by antigen. When antigen come in contact with B-cells, it undergoes clonal proliferation and divided into memory cells and plasma cells.
2. What is the meaning of thymus independent B-cell activation?
a) Without the participation of T-cell
b) Do not mature in the thymus
c) Thymus would not take part in its activation
d) Affinity maturation takes place in the thymus
Explanation: In thymus independent B-cell pathway, antigen activates B-cell without the participation of TH cell. Response generated by thymus independent antigens only generate IgM and do not give rise to memory.
3. Which of the following acts as a coreceptor for B-cell activation?
Explanation: CD19, CD81, and CD21 are present on the B-cell membrane and known as a B-cell coreceptor. These receptors are used to determine a cell’s identity and for transducing signals.
4. Out of these, which transcription factor does not take part in B-cell activation?
b) NF- kB
Explanation: Transcription factors like NF-AT, CREB, JUN, FOS, and AP-1 promote gene expression required for B-cell proliferation into a plasma cell and the memory cell.
5. Hybridoma technology is used to produce___________
b) Monoclonal antibodies
d) Immune response
Explanation: It is a method which is used for the production of hybridoma of B-cells. This hybridoma B-cell later used for the production of monoclonal antibodies. Monoclonal antibodies are highly specific against a single epitope of the antigen.
6. Name the drug which is used to isolate hybridoma cells from the media?
Explanation: Aminopterin inhibits dHFR enzyme and block denovo pathway of nucleotide synthesis, which further allow the survival of only hybridoma cells and B-cells in HAT media.
7. Name the most commonly used monoclonal antibody for treatment of breast cancer?
Explanation: Monoclonal antibodies are specific against the particular antigen and these are used to treat the cancer as they release their toxins in the growing cells which interfere with their cellular processes. Herceptin is particularly for breast cancer while erbutir is for colorectal cancer.
8. Mark the one which is NOT used in generating antibody diversity?
a) Combinatorial V(D)J joining
b) Juntional and insertional diversification
c) Somatic hypermutation
d) Binary fission
Explanation: Different classes of antibodies have variable amino acid sequences at the N-terminal end which interacts with different types of antigens. Four theories have been proposed for generating antibody diversity.
9. Tolerance of self-antigen by B-cells are known as B-cell tolerance.
Explanation: Self tolerance is the process by which the immune system does not attack self antigen. Immunological tolerance of B-cell is called B-cell tolerance, B-cell produced by this process does not recognize self-antigen but may recognize non-self antigens.
Sanfoundry Global Education & Learning Series – Life Sciences.
To practice all areas of Life Sciences, here is complete set of 1000+ Multiple Choice Questions and Answers.