1. The presence of O-specific side chains makes a cell sensitive to _____________
a) 6SR
b) P22
c) Br2
d) Br60
Explanation: The presence of O-specific side chains makes the cell sensitive to phages such as P22, Felix O, etc. and resistant to phages such as 6SR, Br2, Br60, etc. The absence of O-specific side chains makes the cell resistant to phages such as P22, Felix O, etc. and sensitive to phages such as 6SR, Br2, Br60, etc.
2. Which of the following compound inhibits the entry of the HIV-1 virus?
a) Zanamivir
b) Oseltamivir
c) Pleconaril
d) Enfuvirtide
Explanation: Enfuvirtide is an antiviral compound that prevents or inhibits the attachment and entry of the HIV-1 virus into the host cells. It is an antiretroviral drug and is also known as T-20.
3. The entry of picornaviruses is inhibited by zanamivir.
a) True
b) False
Explanation: The attachment and entry of picornaviruses are inhibited by pleconaril, which is an antiviral compound that prevents the uncoating of the viral RNA genome.
4. Which of the following protein helps in the removal of primers in SV40 replication?
a) T antigen
b) DNA ligase
c) RNase H
d) RNase A
Explanation: RNase H is an enzyme or protein which helps in the removal of primers in SV40 replication. Its function is to degrade RNA within RNA: DNA hybrid systems. Whereas RNase A degrades the RNA from RNA: RNA hybrids.
5. DNA ligase has the function the same as a fevicol.
a) True
b) False
Explanation: DNA ligase is an enzyme or protein which joins the ends of DNA molecules, thus acting as a fevicol. It performs many important roles in the replication processes such as connecting Okazaki fragments, sealing repairs in the DNA molecule, etc.
6. Which of the following protein recognizes MHC class I proteins?
a) CD4
b) CD8
c) CD26
d) CD10
Explanation: CD8 (Cluster of Differentiation) is an integral transmembrane glycoprotein present on the surface of T cells that recognizes MHC (Major Histocompatibility Complex) class I proteins.
7. Which of the following is a primary lymphoid organ?
a) Lymph
b) Spleen
c) MALT
d) Bone marrow
Explanation: Bone marrow is a primary lymphoid organ. It is an organ where lymphocytes (B & T) arise there. 90% of plasma antibodies come from B cells in the bone marrow.
8. T cells mature in ______________
a) bone marrow
b) thymus
c) spleen
d) lymph
Explanation: The maturation of T lymphocytes or T cells occurs in the thymus. The development or formation of T cells occurs in the bone marrow and then T cells travel through the bloodstream to the thymus and mature there. B cells mature in the bone marrow.
9. Hematopoiesis occurs in ______________
a) Thymus
b) Spleen
c) Bone marrow
d) MALT
Explanation: Hematopoiesis occurs in the bone marrow. Hematopoiesis is the process of formation of all the types of blood cells from hematopoietic stem cells (HSCs) present in the bone marrow.
10. Which of the following controls the release of hematopoietic cells from bone marrow?
a) Osteoblasts
b) Endothelial cells
c) Sympathetic neurons
d) Reticular cells
Explanation: Sympathetic neurons controls the release of hematopoietic cells from the bone marrow. The adult bone marrow contains several cell types that coordinate HSC development including, osteoblasts, endothelial cells, reticular cells, and sympathetic neurons.