BIO 2100 Exam 3 | Microbiology | 2026 Update |100% Correct
– Galen College
1. Which statement best describes first-line defenses?
A) Intact skin, mucous membranes, secretions, and normal microbiota form important first-line defenses.
B) First-line defense is produced only after vaccination
C) First-line defense depends on antigen-specific memory
D) First-line defense consists only of circulating antibodies
Correct Answer: Intact skin, mucous membranes, secretions, and normal microbiota form important first-
line defenses.
Rationale: Innate barriers act rapidly and nonspecifically, reducing entry and colonization before adaptive immune
responses are required. The alternatives confuse this concept with a different immune, pathogenic, or epidemiologic
mechanism.
2. A clinical microbiology scenario requires application of first-line defenses. Which interpretation
ismost accurate?
A) First-line defense consists only of circulating antibodies
B) First-line defense depends on antigen-specific memory
C) First-line defense is produced only after vaccination
D) Intact skin, mucous membranes, secretions, and normal microbiota form important first-line defenses.
Correct Answer: Intact skin, mucous membranes, secretions, and normal microbiota form important first-
line defenses.
Rationale: Innate barriers act rapidly and nonspecifically, reducing entry and colonization before adaptive immune
responses are required. In an applied setting, recognizing this mechanism helps explain host defense, disease
production, transmission, or prevention.
3. Which statement best describes phagocytosis?
A) Phagocytosis requires prior antibody production in every case
B) Neutrophils and macrophages can engulf and destroy microbes through phagocytosis.
C) Phagocytosis is performed only by B lymphocytes
D) Phagocytosis is viral replication inside a host cell
Correct Answer: Neutrophils and macrophages can engulf and destroy microbes through phagocytosis.
Rationale: Phagocytes recognize, engulf, and kill particles or microbes. Opsonization can enhance the process but is
not required for every phagocytic event. The alternatives confuse this concept with a different immune, pathogenic, or
epidemiologic mechanism.
4. During infection-control review, the team considers phagocytosis. Which conclusion best
appliesthe principle?
A) Neutrophils and macrophages can engulf and destroy microbes through phagocytosis.
B) Phagocytosis is performed only by B lymphocytes
C) Phagocytosis is viral replication inside a host cell
D) Phagocytosis requires prior antibody production in every case
Correct Answer: Neutrophils and macrophages can engulf and destroy microbes through phagocytosis.
Page 2
, BIO 2100 - Exam 3 Practice Study Guide
Rationale: Phagocytes recognize, engulf, and kill particles or microbes. Opsonization can enhance the process but is
not required for every phagocytic event. In an applied setting, recognizing this mechanism helps explain host defense,
disease production, transmission, or prevention.
5. Which statement best describes inflammation?
A) Inflammation always proves bacterial infection
B) Inflammation is exclusively an adaptive immune process
C) Inflammation recruits cells and mediators to contain injury or infection and initiate repair.
D) Inflammation prevents vascular changes at injured tissue
Correct Answer: Inflammation recruits cells and mediators to contain injury or infection and initiate repair.
Rationale: Inflammation is a coordinated innate response involving vascular changes, mediators, leukocyte recruitment,
containment, and tissue repair. The alternatives confuse this concept with a different immune, pathogenic, or
epidemiologic mechanism.
6. A learner analyzes host-pathogen interactions involving inflammation. Which statement is
bestsupported?
A) Inflammation is exclusively an adaptive immune process
B) Inflammation prevents vascular changes at injured tissue
C) Inflammation recruits cells and mediators to contain injury or infection and initiate repair.
D) Inflammation always proves bacterial infection
Correct Answer: Inflammation recruits cells and mediators to contain injury or infection and initiate repair.
Rationale: Inflammation is a coordinated innate response involving vascular changes, mediators, leukocyte recruitment,
containment, and tissue repair. In an applied setting, recognizing this mechanism helps explain host defense, disease
production, transmission, or prevention.
7. Which statement best describes fever?
A) Fever requires antigen-specific antibodies
B) Pyrogens can raise the hypothalamic temperature set point, producing fever.
C) Fever is caused only by environmental heat
D) Fever begins because the hypothalamic set point falls
Correct Answer: Pyrogens can raise the hypothalamic temperature set point, producing fever.
Rationale: Endogenous mediators induced by infection can alter hypothalamic regulation; chills commonly occur while
body temperature rises toward the higher set point. The alternatives confuse this concept with a different immune,
pathogenic, or epidemiologic mechanism.
8. An epidemiologic investigation highlights fever. Which interpretation should guide the
analysis?
A) Pyrogens can raise the hypothalamic temperature set point, producing fever.
B) Fever is caused only by environmental heat
C) Fever begins because the hypothalamic set point falls
D) Fever requires antigen-specific antibodies
Correct Answer: Pyrogens can raise the hypothalamic temperature set point, producing fever.
Page 3