Microbiology & Immunology Flashcards
6 cards from real B.Pharm. Bachelor of Pharmacy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Microbiology & Immunology flashcards as text
Which bacterial structure protects against phagocytosis and is a major virulence factor for Streptococcus pneumoniae?
Answer: Polysaccharide capsule
The polysaccharide capsule prevents opsonization and phagocytosis by macrophages, making encapsulated bacteria more virulent.
The Gram stain differentiates bacteria based on differences in their:
Answer: Cell wall peptidoglycan thickness
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.
Which type of immunity is acquired naturally by the body's own immune response after exposure to an antigen?
Answer: Active natural immunity
Active natural immunity develops when the body mounts its own immune response after natural infection, producing memory cells and antibodies.
Bacteriostatic antibiotics differ from bactericidal antibiotics in that they:
Answer: Inhibit bacterial growth without killing
Bacteriostatic agents inhibit bacterial reproduction, relying on the host immune system to eliminate the bacteria, while bactericidal agents directly kill bacteria.
Which immunoglobulin class is the most abundant in human serum and provides the main antibody-based defense?
Answer: IgG
IgG is the most abundant immunoglobulin in serum (~75%), providing long-term immunity, crossing the placenta, and activating complement.
D-value (decimal reduction time) in microbiology sterilization refers to the time required to:
Answer: Reduce the microbial population by 90% (1 log)
The D-value is the time at a given temperature required to reduce the number of viable microorganisms by one decimal (10-fold or 90%) reduction.