HSS 1100 - Midterm 1 Review Questions with Correct Answers Latest Update 2025-2026
The term "microbiology" literally means: A) Study of plants B) Study of small life C) Study of
fungi D) Study of viruses - Answers B) Study of small life
Viruses contain: A) DNA and RNA B) Only RNA C) Either DNA or RNA, never both D) Both DNA
and a nucleus - Answers C) Either DNA or RNA, never both
The protein shell surrounding a virus is called: A) Capsid B) Capsule C) Spore D) Pili - Answers A)
Capsid
Which statement about bacteria is TRUE? A) They reproduce by mitosis B) They contain circular
chromosomes C) They have a nucleus D) They lack both DNA and RNA - Answers B) They
contain circular chromosomes
Eukaryotic organisms are distinct from prokaryotes because they: A) Have mitochondria and
nuclei B) Lack DNA C) Only exist as unicellular organisms D) Have only circular chromosomes -
Answers A) Have mitochondria and nuclei
Normal flora that reside permanently are called: A) Pathogens B) Opportunists C) Resident flora
D) Transient flora - Answers C) Resident flora
Transient flora often occur due to: A) Antibiotic resistance B) Displacement, injury, or behavior C)
Genetic mutation D) Viral infections - Answers B) Displacement, injury, or behavior
Which bacterial flora synthesizes vitamin K in humans? A) Skin flora B) Gut flora C)
Nasopharyngeal flora D) Oral flora - Answers B) Gut flora
Skin flora is dominated by: A) S. aureus B) Coagulase-negative staphylococci C) Streptococcus
pyogenes D) Candida species - Answers B) Coagulase-negative staphylococci
Mechanical barriers include all EXCEPT: A) Tears B) Saliva C) Exotoxins D) Hair - Answers C)
Exotoxins
Pathogenicity is defined as: A) Ability to invade tissues B) Ability to produce disease C) Relative
severity of infection D) Ability to cause fever - Answers B) Ability to produce disease
Virulence is: A) Always higher in Gram negatives B) Relative capacity to cause damage C) Same
as pathogenicity D) Determined only by toxins - Answers B) Relative capacity to cause damage
Opportunistic pathogens cause disease: A) In healthy individuals only B) When host defenses
are compromised C) Exclusively in infants D) Only via toxins - Answers B) When host defenses
are compromised
Pili and fimbriae function mainly in: A) Protein synthesis B) Adhesion to host cells C) Resistance
to antibiotics D) Motility - Answers B) Adhesion to host cells
, Capsules enhance: A) Toxin production B) Adherence and protection from phagocytosis C)
Spore formation D) Viral replication - Answers B) Adherence and protection from phagocytosis
Exotoxins are typically: A) Heat-stable proteins B) Secreted proteins with specific effects C)
Released on cell death only D) Less potent than endotoxins - Answers B) Secreted proteins with
specific effects
Endotoxins are released: A) When bacteria are alive and dividing B) When bacterial cell walls
disintegrate C) Only by Gram-positive organisms D) By viruses - Answers B) When bacterial cell
walls disintegrate
Which toxin type is responsible for fever and shock? A) Exotoxin B) Endotoxin C) Enterotoxin D)
Hemolysin - Answers B) Endotoxin
Innate immunity includes: A) Antibodies B) Complement system C) B and T lymphocytes D)
Memory cells - Answers B) Complement system
Adaptive immunity is characterized by: A) Non-specific defense B) Past exposure dependence C)
Lack of memory D) Same response to all invaders - Answers B) Past exposure dependence
Which is NOT part of innate defense? A) Phagocytosis B) Transferrin C) Antibody production D)
Mucous membranes - Answers C) Antibody production
Antibodies are synthesized by: A) T-helper cells B) B lymphocytes/plasma cells C) Neutrophils D)
NK cells - Answers B) B lymphocytes/plasma cells
IgG is important because: A) It crosses the placenta B) It triggers allergies C) It is secreted in
saliva D) It is the first response antibody - Answers A) It crosses the placenta
IgM is the: A) Main mucosal antibody B) Early immune response antibody C) Smallest antibody
D) Allergy-related antibody - Answers B) Early immune response antibody
IgE is primarily involved in: A) Host defense B) Allergic reactions and parasite defense C) Cross-
placental immunity D) Long-term immunity - Answers B) Allergic reactions and parasite defense
The secondary immune response is: A) Slower than primary B) Faster with higher antibody titers
C) Identical to primary D) Independent of memory cells - Answers B) Faster with higher antibody
titers
Antigen presenting cells display antigens on: A) Ribosomes B) Major Histocompatibility
Complex molecules C) Cell membranes only D) Viral proteins - Answers B) Major
Histocompatibility Complex molecules
Th1 cells are associated with: A) Humoral immunity B) Cell-mediated immunity C)
Autoimmunity D) Allergies - Answers B) Cell-mediated immunity
Anaphylaxis is an example of: A) Autoimmune disease B) Hypersensitivity C) Immunodeficiency
The term "microbiology" literally means: A) Study of plants B) Study of small life C) Study of
fungi D) Study of viruses - Answers B) Study of small life
Viruses contain: A) DNA and RNA B) Only RNA C) Either DNA or RNA, never both D) Both DNA
and a nucleus - Answers C) Either DNA or RNA, never both
The protein shell surrounding a virus is called: A) Capsid B) Capsule C) Spore D) Pili - Answers A)
Capsid
Which statement about bacteria is TRUE? A) They reproduce by mitosis B) They contain circular
chromosomes C) They have a nucleus D) They lack both DNA and RNA - Answers B) They
contain circular chromosomes
Eukaryotic organisms are distinct from prokaryotes because they: A) Have mitochondria and
nuclei B) Lack DNA C) Only exist as unicellular organisms D) Have only circular chromosomes -
Answers A) Have mitochondria and nuclei
Normal flora that reside permanently are called: A) Pathogens B) Opportunists C) Resident flora
D) Transient flora - Answers C) Resident flora
Transient flora often occur due to: A) Antibiotic resistance B) Displacement, injury, or behavior C)
Genetic mutation D) Viral infections - Answers B) Displacement, injury, or behavior
Which bacterial flora synthesizes vitamin K in humans? A) Skin flora B) Gut flora C)
Nasopharyngeal flora D) Oral flora - Answers B) Gut flora
Skin flora is dominated by: A) S. aureus B) Coagulase-negative staphylococci C) Streptococcus
pyogenes D) Candida species - Answers B) Coagulase-negative staphylococci
Mechanical barriers include all EXCEPT: A) Tears B) Saliva C) Exotoxins D) Hair - Answers C)
Exotoxins
Pathogenicity is defined as: A) Ability to invade tissues B) Ability to produce disease C) Relative
severity of infection D) Ability to cause fever - Answers B) Ability to produce disease
Virulence is: A) Always higher in Gram negatives B) Relative capacity to cause damage C) Same
as pathogenicity D) Determined only by toxins - Answers B) Relative capacity to cause damage
Opportunistic pathogens cause disease: A) In healthy individuals only B) When host defenses
are compromised C) Exclusively in infants D) Only via toxins - Answers B) When host defenses
are compromised
Pili and fimbriae function mainly in: A) Protein synthesis B) Adhesion to host cells C) Resistance
to antibiotics D) Motility - Answers B) Adhesion to host cells
, Capsules enhance: A) Toxin production B) Adherence and protection from phagocytosis C)
Spore formation D) Viral replication - Answers B) Adherence and protection from phagocytosis
Exotoxins are typically: A) Heat-stable proteins B) Secreted proteins with specific effects C)
Released on cell death only D) Less potent than endotoxins - Answers B) Secreted proteins with
specific effects
Endotoxins are released: A) When bacteria are alive and dividing B) When bacterial cell walls
disintegrate C) Only by Gram-positive organisms D) By viruses - Answers B) When bacterial cell
walls disintegrate
Which toxin type is responsible for fever and shock? A) Exotoxin B) Endotoxin C) Enterotoxin D)
Hemolysin - Answers B) Endotoxin
Innate immunity includes: A) Antibodies B) Complement system C) B and T lymphocytes D)
Memory cells - Answers B) Complement system
Adaptive immunity is characterized by: A) Non-specific defense B) Past exposure dependence C)
Lack of memory D) Same response to all invaders - Answers B) Past exposure dependence
Which is NOT part of innate defense? A) Phagocytosis B) Transferrin C) Antibody production D)
Mucous membranes - Answers C) Antibody production
Antibodies are synthesized by: A) T-helper cells B) B lymphocytes/plasma cells C) Neutrophils D)
NK cells - Answers B) B lymphocytes/plasma cells
IgG is important because: A) It crosses the placenta B) It triggers allergies C) It is secreted in
saliva D) It is the first response antibody - Answers A) It crosses the placenta
IgM is the: A) Main mucosal antibody B) Early immune response antibody C) Smallest antibody
D) Allergy-related antibody - Answers B) Early immune response antibody
IgE is primarily involved in: A) Host defense B) Allergic reactions and parasite defense C) Cross-
placental immunity D) Long-term immunity - Answers B) Allergic reactions and parasite defense
The secondary immune response is: A) Slower than primary B) Faster with higher antibody titers
C) Identical to primary D) Independent of memory cells - Answers B) Faster with higher antibody
titers
Antigen presenting cells display antigens on: A) Ribosomes B) Major Histocompatibility
Complex molecules C) Cell membranes only D) Viral proteins - Answers B) Major
Histocompatibility Complex molecules
Th1 cells are associated with: A) Humoral immunity B) Cell-mediated immunity C)
Autoimmunity D) Allergies - Answers B) Cell-mediated immunity
Anaphylaxis is an example of: A) Autoimmune disease B) Hypersensitivity C) Immunodeficiency
