BIO 169 FINAL EXAM 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔What is the function of the thymus? - ✔✔Maturation of T lymphocytes by
1. Seal the developing T lymphocytes from bloodborne Ag by blood-thymus barrier.
2. Secrete thymic hormones: thymosin and thymopoietin to regulate the development
and maturation of T lymphocytes
✔✔What is the function of the lymph nodes? - ✔✔1. Filtration and clean the lymph.
2. Site of T and B lymphocytes activation and initiation of the specific immune response.
✔✔What is the location of the tonsil? - ✔✔1. Palatine tonsils: pair at posterior margin of
oral cavity - largest.
2. Lingual tonsils at the root of tongue.
3. Pharyngeal tonsil (adenoid) single tonsil on wall of pharynx.
✔✔What is the function of the spleen? - ✔✔1. Hematological functions: removal of
abnormal and old red blood cells.
2. Immune function: filtration of blood and Initiation of the specific immune response
✔✔What are the three lines of defenses against disease? - ✔✔1. The first line of
defense: Nonspecific defense
2. The first second of defense: Nonspecific defense
3. The third line of defense: Specific defense - Mediated by Immune system
✔✔What is the first line of defense in the immune system? - ✔✔Innate immune
response.
Barriers that prevent pathogens from entering the body.
✔✔What is the second line of defense in the immune system? - ✔✔Innate immune
response.
Rapid but nonspecific.
It consists of several internal nonspecific defense mechanisms against pathogen
✔✔What is the third line of defense in the immune system? - ✔✔Adaptive immune
response.
Slower but more specific and effective
✔✔What are the six internal nonspecific defense mechanisms of the second line of
defense? - ✔✔1. Phagocytosis
2. Immunological surveillance
3. Interferons
4. Complement
5. Inflammation
6. Fever
, ✔✔What is phagocytosis (immune system) - ✔✔Monocyte-macrophage system and
Microphages: Neutrophils & Eosinophils
✔✔What is immunological surveillance? - ✔✔Natural Killer cells (NK lymphocytes)
✔✔What is interferons? - ✔✔Small proteins released by virally infected cells and trigger
the production of antiviral proteins
✔✔What is complement - ✔✔Groups of globulins that Enhance phagocytosis and
Stimulate inflammation
✔✔What are the four cardinal signs of inflammation? - ✔✔1. Redness (erythema) due
to hyperemia caused by vasodilatation (increase blood flow)
2. Swelling (edema) caused by increased capillary permeability and filtration.
3. Heat due to hyperemia caused by vasodilatation.
4. Pain and loss of function caused by inflammatory chemicals (bradykinin,
prostaglandins) secreted by damaged cells, pressure on nerves
✔✔What is a fever? - ✔✔Pyrogens (pathogens) reset the hypothalamic thermostat and
raise body temperature. The fever increases the effects of antimicrobial substances,
inhibits some microbes from growing and increases the rate of cellular repair
✔✔What are the four properties of immunity? Which ones are only for specific
immunity? - ✔✔1. Tolerance - responds to foreign substances (Ag) but ignores normal
tissues.
* 2. Specificity - activated by and responds to a specific antigen.
3. Versatility - is ready to confront any antigen at any time.
* 4. Memory - "remembers" any antigen it has encountered.
✔✔What is the primary cell of humoral immune response? - ✔✔B lymphocytes
✔✔What are the primary cells of cell mediated immune response? - ✔✔T cytotoxic
lymphocytes
✔✔What are the steps of the humoral immune response? - ✔✔1. Extracellular Ag
(pathogen)
2. Antigen triggers an immune response
3.Macrophages (APCs) presented antigen to T helper cells.
4. T helper cells stimulate B cells
5. proliferation and activation of the specific B cells
6. effector cells; plasma cells + memory cells
7. plasma cells produce antibodies
8. antibodies attack the antigen
SOLUTIONS RATED A+
✔✔What is the function of the thymus? - ✔✔Maturation of T lymphocytes by
1. Seal the developing T lymphocytes from bloodborne Ag by blood-thymus barrier.
2. Secrete thymic hormones: thymosin and thymopoietin to regulate the development
and maturation of T lymphocytes
✔✔What is the function of the lymph nodes? - ✔✔1. Filtration and clean the lymph.
2. Site of T and B lymphocytes activation and initiation of the specific immune response.
✔✔What is the location of the tonsil? - ✔✔1. Palatine tonsils: pair at posterior margin of
oral cavity - largest.
2. Lingual tonsils at the root of tongue.
3. Pharyngeal tonsil (adenoid) single tonsil on wall of pharynx.
✔✔What is the function of the spleen? - ✔✔1. Hematological functions: removal of
abnormal and old red blood cells.
2. Immune function: filtration of blood and Initiation of the specific immune response
✔✔What are the three lines of defenses against disease? - ✔✔1. The first line of
defense: Nonspecific defense
2. The first second of defense: Nonspecific defense
3. The third line of defense: Specific defense - Mediated by Immune system
✔✔What is the first line of defense in the immune system? - ✔✔Innate immune
response.
Barriers that prevent pathogens from entering the body.
✔✔What is the second line of defense in the immune system? - ✔✔Innate immune
response.
Rapid but nonspecific.
It consists of several internal nonspecific defense mechanisms against pathogen
✔✔What is the third line of defense in the immune system? - ✔✔Adaptive immune
response.
Slower but more specific and effective
✔✔What are the six internal nonspecific defense mechanisms of the second line of
defense? - ✔✔1. Phagocytosis
2. Immunological surveillance
3. Interferons
4. Complement
5. Inflammation
6. Fever
, ✔✔What is phagocytosis (immune system) - ✔✔Monocyte-macrophage system and
Microphages: Neutrophils & Eosinophils
✔✔What is immunological surveillance? - ✔✔Natural Killer cells (NK lymphocytes)
✔✔What is interferons? - ✔✔Small proteins released by virally infected cells and trigger
the production of antiviral proteins
✔✔What is complement - ✔✔Groups of globulins that Enhance phagocytosis and
Stimulate inflammation
✔✔What are the four cardinal signs of inflammation? - ✔✔1. Redness (erythema) due
to hyperemia caused by vasodilatation (increase blood flow)
2. Swelling (edema) caused by increased capillary permeability and filtration.
3. Heat due to hyperemia caused by vasodilatation.
4. Pain and loss of function caused by inflammatory chemicals (bradykinin,
prostaglandins) secreted by damaged cells, pressure on nerves
✔✔What is a fever? - ✔✔Pyrogens (pathogens) reset the hypothalamic thermostat and
raise body temperature. The fever increases the effects of antimicrobial substances,
inhibits some microbes from growing and increases the rate of cellular repair
✔✔What are the four properties of immunity? Which ones are only for specific
immunity? - ✔✔1. Tolerance - responds to foreign substances (Ag) but ignores normal
tissues.
* 2. Specificity - activated by and responds to a specific antigen.
3. Versatility - is ready to confront any antigen at any time.
* 4. Memory - "remembers" any antigen it has encountered.
✔✔What is the primary cell of humoral immune response? - ✔✔B lymphocytes
✔✔What are the primary cells of cell mediated immune response? - ✔✔T cytotoxic
lymphocytes
✔✔What are the steps of the humoral immune response? - ✔✔1. Extracellular Ag
(pathogen)
2. Antigen triggers an immune response
3.Macrophages (APCs) presented antigen to T helper cells.
4. T helper cells stimulate B cells
5. proliferation and activation of the specific B cells
6. effector cells; plasma cells + memory cells
7. plasma cells produce antibodies
8. antibodies attack the antigen
