B.Pharm. Bachelor of Pharmacy Microbiology & Immunology 1

Question 1

Which bacterial structure protects against phagocytosis and is a major virulence factor for Streptococcus pneumoniae?

Accepted Answer

Polysaccharide capsule

Answer

The polysaccharide capsule prevents opsonization and phagocytosis by macrophages, making encapsulated bacteria more virulent.

Question 2

The Gram stain differentiates bacteria based on differences in their:

Accepted Answer

Cell wall peptidoglycan thickness

Answer

Gram-positive bacteria have a thick peptidoglycan layer that retains crystal violet dye, while Gram-negative bacteria have a thinner layer and outer membrane causing them to appear pink after safranin counterstain.

Question 3

Which type of immunity is acquired naturally by the body's own immune response after exposure to an antigen?

Accepted Answer

Active natural immunity

Answer

Active natural immunity develops when the body mounts its own immune response after natural infection, producing memory cells and antibodies.

Question 4

Bacteriostatic antibiotics differ from bactericidal antibiotics in that they:

Accepted Answer

Inhibit bacterial growth without killing

Answer

Bacteriostatic agents inhibit bacterial reproduction, relying on the host immune system to eliminate the bacteria, while bactericidal agents directly kill bacteria.

Question 5

Which immunoglobulin class is the most abundant in human serum and provides the main antibody-based defense?

Accepted Answer

IgG

Answer

IgG is the most abundant immunoglobulin in serum (~75%), providing long-term immunity, crossing the placenta, and activating complement.

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Microbiology & Immunology 1