1. What does susceptibility mean in the context of host defenses?
• A) Ability to resist disease
• B) Lack of resistance to disease
• C) Immunity against a specific pathogen
• D) Adaptive immunity

B

1. What is the primary function of the immune system?
• A) To produce red blood cells
• B) To ward off disease
• C) To transport oxygen
• D) To digest food

B

1. What is nonspecific resistance also known as?
• A) Adaptive immunity
• B) Innate immunity
• C) Passive immunity
• D) Acquired immunity

B

1. What type of immunity is slower to respond but has a memory component?
• A) Nonspecific resistance
• B) Innate immunity
• C) Specific resistance
• D) Temporary immunity

C

1. Which physical factor involves the tightly packed cells with keratin?
• A) Mucous membranes
• B) Skin
• C) Ciliary escalator
• D) Lacrimal apparatus

B

1. What is the role of mucous membranes in host defense?
• A) To secrete sebum
• B) To trap microbes
• C) To produce antibodies
• D) To filter blood

B

1. What mechanism transports microbes trapped in mucus away from the lungs?
• A) Peristalsis
• B) Ciliary escalator
• C) Defecation
• D) Vomiting

B

1. Which fluid washes away microbes from the eyes?
• A) Saliva
• B) Urine
• C) Vaginal secretions
• D) Tears

D

1. What substance in saliva helps prevent colonization of teeth by microbes?
• A) Lysozyme
• B) Sebum
• C) Gastric juice
• D) Earwax

A

1. Which of the following prevents microbes from entering the ear?
• A) Tears
• B) Urine
• C) Earwax
• D) Saliva

C

1. What is the pH of the skin that inhibits the growth of pathogens?
• A) 7
• B) 5
• C) 3
• D) 9

B

1. What enzyme found in perspiration, tears, and saliva destroys cell walls of microbes?
• A) Pepsin
• B) Amylase
• C) Lysozyme
• D) Lactase

C

1. What pH range of gastric juice kills most microbes?
• A) 1.2 - 3.0
• B) 4.0 - 6.0
• C) 6.0 - 7.5
• D) 7.5 - 8.5

A

1. What is microbial antagonism also known as?
• A) Commensalism
• B) Parasitism
• C) Competitive exclusion
• D) Mutualism

C

1. Which bacteria produce bacteriocins that inhibit the growth of Salmonella and Shigella?
• A) Streptococcus
• B) E. coli
• C) Staphylococcus
• D) Bacillus

B

1. How many bacteria are there approximately on a human body?
• A) 1 x 10^6
• B) 1 x 10^8
• C) 1 x 10^12
• D) 1 x 10^14

D

1. What is the normal range of white blood cell count per cubic millimeter?
• A) 2,000–5,000
• B) 5,000–10,000
• C) 10,000–15,000
• D) 15,000–20,000

B

1. What percentage of white blood cells are neutrophils?
• A) 20% to 25%
• B) 3% to 8%
• C) 2% to 4%
• D) 60% to 70%

D

1. Which cells are involved in specific immunity?
• A) Neutrophils
• B) Monocytes
• C) Lymphocytes
• D) Eosinophils

C

1. What are the cells that differentiate into macrophages called?
• A) Eosinophils
• B) Monocytes
• C) Basophils
• D) Lymphocytes

B

1. Where are dendritic cells commonly found?
• A) Bloodstream
• B) Skin and mucous membranes
• C) Bone marrow
• D) Lymph nodes

B

1. What is the primary function of lymphocytes?
• A) Phagocytosis
• B) Oxygen transport
• C) Specific immunity
• D) Blood clotting

C

1. Which cells release histamine during an allergic reaction?
• A) Neutrophils
• B) Eosinophils
• C) Basophils
• D) Monocytes

C

1. What is the role of phagocytes in the immune system?
• A) Produce antibodies
• B) Destroy pathogens by engulfing them
• C) Secrete mucus
• D) Produce histamine

B

1. What are fixed macrophages that reside in the liver called?
• A) Microglia
• B) Kupffer cells
• C) Osteoclasts
• D) Langerhans cells

B

1. What do free (wandering) macrophages do?
• A) Remain fixed in tissues
• B) Roam tissues and gather at sites of infection
• C) Secrete digestive enzymes
• D) Produce antibodies

B

1. Which phase of phagocytosis involves the attraction of phagocytes to microorganisms?
• A) Adherence
• B) Chemotaxis
• C) Ingestion
• D) Digestion

B

1. What is opsonization in the context of phagocytosis?
• A) The attachment of a phagocyte to the surface of a microorganism
• B) The coating of a microorganism with serum proteins
• C) The ingestion of a microorganism by a phagocyte
• D) The digestion of a microorganism inside a phagolysosome

B

1. What are toll-like receptors (TLRs) involved in?
• A) Oxygen transport
• B) Pathogen recognition
• C) Hormone secretion
• D) Protein synthesis

B

1. Which cells play a role in the inflammatory response by releasing cytokines?
• A) Red blood cells
• B) Neutrophils
• C) T-helper cells
• D) Platelets

C

1. What are the cardinal signs of inflammation?
• A) Redness, pain, heat, swelling, loss of function
• B) Fever, nausea, fatigue, headache, dizziness
• C) Coughing, sneezing, sore throat, runny nose, congestion
• D) Itching, rash, swelling, hives, fever

A

1. Which phase of the inflammatory response involves the increase in permeability of blood vessels?
• A) Chemotaxis
• B) Adherence
• C) Edema
• D) Diapedesis

C

1. What chemical is responsible for vasodilation during inflammation?
• A) Histamine
• B) Lysozyme
• C) Pepsin
• D) Amylase

A

1. Which cells produce interleukin-1 (IL-1) during an inflammatory response?
• A) Red blood cells
• B) Macrophages
• C) Platelets
• D) Eosinophils

B

1. What does IL-1 stimulate in the hypothalamus?
• A) Decreased metabolism
• B) Increased appetite
• C) Release of prostaglandins
• D) Production of antibodies

C

1. Which organ produces serum proteins that assist in destroying microbes?
• A) Kidney
• B) Heart
• C) Liver
• D) Pancreas

C

1. What does complement activation result in?
• A) Protein synthesis
• B) Phagocytosis
• C) Cytolysis, opsonization, inflammation
• D) Hormone secretion

C

1. Which pathway of complement activation involves antibodies?
• A) Alternative pathway
• B) Classical pathway
• C) Lectin pathway
• D) Direct pathway

B

1. What components combine to activate C3 in the classical pathway?
• A) C1 and C4
• B) C2 and C4
• C) B and D
• D) C1 and C2

B

1. What is the role of C3b in the complement system?
• A) Inflammation
• B) Cytolysis
• C) Opsonization
• D) All of the above

D

1. Which pathway of complement activation does not involve antibodies?
• A) Classical pathway
• B) Lectin pathway
• C) Alternative pathway
• D) Direct pathway

C

1. What factors combine with C3 in the alternative pathway?
• A) A, B, C
• B) B, D, P
• C) C1, C2, C4
• D) E, F, G

B

1. What results from the activation of C3a in the complement system?
• A) Phagocytosis
• B) Cytolysis
• C) Inflammation
• D) Opsonization

C

1. Which cells play a role in both phagocytosis and antigen presentation?
• A) Red blood cells
• B) Dendritic cells
• C) Platelets
• D) Eosinophils

B

1. What process involves neutrophils clinging to the walls of capillaries in the injured area?
• A) Chemotaxis
• B) Margination
• C) Diapedesis
• D) Adherence

B

1. Which immune cells are the primary responders during the initial phase of inflammation?
• A) Lymphocytes
• B) Eosinophils
• C) Basophils
• D) Neutrophils

D

1. What effect does fever have on the liver and spleen?
• A) Increases blood flow
• B) Reserves iron
• C) Produces antibodies
• D) Decreases metabolism

B

1. Which immune cells are involved in the body's response to parasitic worms?
• A) Neutrophils
• B) Eosinophils
• C) Monocytes
• D) Basophils

B

1. What is the role of prostaglandins in inflammation?
• A) Cause vasodilation
• B) Intensify the effects of kinins
• C) Produce antibodies
• D) Decrease permeability of blood vessels

B

1. Which cytokine is primarily responsible for fever induction?
• A) Interleukin-1 (IL-1)
• B) Tumor necrosis factor (TNF)
• C) Interleukin-6 (IL-6)
• D) Interferon-gamma (IFN-γ)

A

1. What stimulates lectin production in the liver?
• A) Antibodies
• B) Cytokines
• C) Prostaglandins
• D) Histamines

B

1. What does Mannose-binding lectin (MBL) bind to?
• A) Lipopolysaccharides
• B) Peptidoglycan
• C) Mannose
• D) Glycogen

C

1. Which proteins are activated by MBL in the lectin pathway?
• A) C1 and C3
• B) C2 and C4
• C) C3 and C5
• D) B and D

B

1. What is the result of C2a and C4b activation in the lectin pathway?
• A) Formation of C1 complex
• B) Activation of C3
• C) Production of antibodies
• D) Release of cytokines

B