This set of Immunology Multiple Choice Questions & Answers (MCQs) focuses on “Receptor-Ligand Interactions”.
1. What are the signaling molecules of the immune system?
a) Transmitters
b) Antigens
c) Chemokines
d) Cytokines
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Explanation: Antigens are the foreign molecules and they act as the signal that indicates the presence of non-self molecules in the body. Cytokines are the molecules that are responsible for the interaction of the various immune cells.
2. What type of bond in NOT formed between a ligand and a receptor?
a) Covalent bond
b) Van der Wall interaction
c) Ionic bonds
d) Hydrogen bonds
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Explanation: A receptor and ligand bond is the same as an enzyme and substrate linkage. They do not bind with strong forces like covalent bonds. Rather, they bind with reversible bonds like hydrogen bonds, ionic bonds, van der Waals interactions etc.
3. In the equation R + L 
RL, what does the ratio k1/k-1 represent?
a) Rate constant
b) Dissociation constant
c) Bond strength
d) Association constant
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Explanation: The ratio of k1/k-1 represents the association constant of the reaction taking place between the ligand and the receptor. It defines the affinity between the ligand and its receptor. k1 is the forward or association rate constant and k-1 is reverse or dissociation rate constant.
4. The pathway used for the ligand-receptor interaction is called as _______________
a) Apoptotic pathway
b) Signal transduction pathway
c) Neurotic pathway
d) Receptor pathway
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Explanation: The cells take a molecular pathway called the Signal transduction pathway to sense the ligand-receptor interaction. This pathway translates this interaction to the individual immune cells.
5. The components of the signaling pathway that are closed to the receptors are called as ________
a) Inward components
b) Downward components
c) Upstream components
d) Downstream components
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Explanation: In signaling pathway, upstream components are the ones that are close to the receptors. On the other hand, downstream components are those which are close to the effector molecules.
6. What are the two types of antigen receptors present on the surface of naïve B-cells?
a) Ig M and Ig D
b) Ig G and Ig E
c) Ig A and Ig D
d) Ig E and Ig M
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Explanation: The presence of immunoglobulin M and immunoglobulin Das antigenic receptors has been seen on the naïve B-cells. These receptors are known to change conformations upon the binding of the antigen.
7. What is the full form of ITAM?
a) Immuno transfer activation molecule
b) Immuno tyrosine activation molecule
c) Immuno tolerant activation motif
d) Immuno-receptor tyrosine activation motif
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Explanation: The immuno-receptor tyrosine activation motifs are a type of sequence motifs. These are found on multiple tyrosine containing signaling proteins in the immune system that are phosphorylated after the signal transduction.
8. The specialized regions in the cell membranes for the ligand receptors are called as _______
a) Lipid shafts
b) Lipid rafts
c) Lipid grafts
d) Lipid drafts
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Explanation: The receptors move to the lipid rafts after extensive clustering due to the ligand binding. This extensive clustering of the B-cell and T-cell receptors is known to slow the diffusion rate in the cell membranes.
9. NFAT is ______________
a) Nuclear factor of Associated T cells
b) Native factor of Activated T cells
c) Nuclear factor of Activated T cells
d) Native factor of Associated T cells
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Explanation: The full form of NFAT is Nuclear Factor of Activated T cells. NFAT is a family if five transcription factors that play a role in dephosphorylation.
10. Which of the following is a component of the inner face of a eukaryotic cytoplasmic membrane?
a) PIP2
b) PI3
c) PIP3
d) IP3
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Explanation: PIP2 (Phosphatidyl Inositol bis-Phosphate) is a phospholipid and it is present in the inner face of the eukaryotic cytoplasmic membrane. PIP2 also takes part in cell signaling during immune reactions.
Sanfoundry Global Education & Learning Series – Immunology.
To practice all areas of Immunology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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