BIO 169 ACTUAL 2026/2027 TEST PAPER QUESTIONS
AND SOLUTIONS RATED A+
✔✔Explain the general function of interferons - ✔✔target intracellular pathogens,
interfere with the process of pathogen replication in our cells
✔✔Define the complement system and describe how it is activated and participates in
providing innate immunity - ✔✔a diverse array of antimicrobial proteins (about 30) that
are produced by liver and released into blood to enhance the immune response
activated
- classical pathway : triggered when antibodies bind to antigens on a pathogen (links
innate to adaptive)
-alternative pathway : a complement protein binds to surface polysaccharides of certain
bacterial and fungal cell walls
-mannose-binding lectin pathway : a protein produced by the liver binds to a specific
carbohydrate on certain microorganisms and complement then binds to lectin protein
✔✔Define inflammation and discuss the basic steps involved including the formation of
exudate and its role in removing harmful substances - ✔✔an immediate, local, non-
specific event that occurs in vascularized tissue against a variety of injury-causing
stimuli
1. release of chemicals
2. vascular change : vasodilation, capillary permeability increase, and stimulation of
capillary endothelium to provide molecules for leukocyte adhesion
3. recruitment of leukocytes: margination, diapedesis, chemotaxis
4. delivery of plasma proteins to site
✔✔Describe the benefits of inflammation - ✔✔-helping eliminate pathogens by limiting
their spread
-destroying infectious agents
-removing cellular debris
-producing the conditions for tissue repair and healing
✔✔List the cardinal signs of inflammation and why each occurs - ✔✔redness: increased
blood flow
heat: increased blood flow and increased metabolic activity within area
swelling: increase in fluid loss from capillaries into interstitial space
pain: stimulation of pain receptors from compression due to accumulation of interstitial
fluid
loss of function: more severe pain and swelling
✔✔Define a fever and how it occurs - ✔✔an abnormal elevation of core body temp of at
least 1.8 F from 98.6 F
, release of fever-inducing molecules called pyrogens that are released from infectious
agents (bacteria) or immune cells in response to trauma, infection, drug reactions and
brain tumors
physiological process that helps in providing innate immunity and may accompany the
inflammatory response
✔✔List the risk and benefits of fever - ✔✔benefits : inhibits replication of bacteria and
viruses, promotes interferon activity, increases activity of lymphocytes, and accelerates
tissue repair
risks : fevers -103-104 changes in metabolic pathways and denaturation of body
proteins, seizure temp over 102, irreversible brain damage over 106 and death over 108
✔✔Describe the features of an antigen and what is meant by antigenic determinant -
✔✔a foreign substance that stimulates an immune response, usually a large and
complex molecule such as protein or polysaccharide
antigenic determinant: specific region of the antigen that antibodies or immune cell
receptors recognize and bind to
✔✔Explain immunogenicity and list attributes that affect it - ✔✔ability if an antigen to
provoke an immune response
affected by
-foreignness : immune system responds best to substances that are recognized as non-
self
-molecular size : larger = more immunogenic
-chemical complexity : proteins most immunogenic, lipids and nucleic acids weak
structural stability : molecules that maintain a stable-three dimensional structure are
more easily recognized by immune cells
-susceptibility to processing : antigens must be broken down by antigen-presenting cells
so fragments can be displayed to lymphocytes
-dose and route of exposure : ex injection, inhalation, ingestion and how much
✔✔Define a hapten and describe how haptens stimulate immune response - ✔✔a small
molecule that cannot by itself stimulate an immune response but can become
immunogenic when it attaches to a larger carrier molecule- usually a proton
stimulation :
1. attaches to carrier protein in body
2. hapten-carrier complex acts as a new antigen
3. antigen-presenting cells process the complex and present it to lymphocytes
4. The immune response produces antibodies against the hapten portion of the complex
5. Future exposure to the hapten can trigger an immune response, especially if it again
attaches to body proteins
✔✔Define receptors of both T lymphocytes and B lymphocytes - ✔✔TCR: recognize
antigen fragments presented by MHC molecules
BCR: recognize free, intact antigens directly
AND SOLUTIONS RATED A+
✔✔Explain the general function of interferons - ✔✔target intracellular pathogens,
interfere with the process of pathogen replication in our cells
✔✔Define the complement system and describe how it is activated and participates in
providing innate immunity - ✔✔a diverse array of antimicrobial proteins (about 30) that
are produced by liver and released into blood to enhance the immune response
activated
- classical pathway : triggered when antibodies bind to antigens on a pathogen (links
innate to adaptive)
-alternative pathway : a complement protein binds to surface polysaccharides of certain
bacterial and fungal cell walls
-mannose-binding lectin pathway : a protein produced by the liver binds to a specific
carbohydrate on certain microorganisms and complement then binds to lectin protein
✔✔Define inflammation and discuss the basic steps involved including the formation of
exudate and its role in removing harmful substances - ✔✔an immediate, local, non-
specific event that occurs in vascularized tissue against a variety of injury-causing
stimuli
1. release of chemicals
2. vascular change : vasodilation, capillary permeability increase, and stimulation of
capillary endothelium to provide molecules for leukocyte adhesion
3. recruitment of leukocytes: margination, diapedesis, chemotaxis
4. delivery of plasma proteins to site
✔✔Describe the benefits of inflammation - ✔✔-helping eliminate pathogens by limiting
their spread
-destroying infectious agents
-removing cellular debris
-producing the conditions for tissue repair and healing
✔✔List the cardinal signs of inflammation and why each occurs - ✔✔redness: increased
blood flow
heat: increased blood flow and increased metabolic activity within area
swelling: increase in fluid loss from capillaries into interstitial space
pain: stimulation of pain receptors from compression due to accumulation of interstitial
fluid
loss of function: more severe pain and swelling
✔✔Define a fever and how it occurs - ✔✔an abnormal elevation of core body temp of at
least 1.8 F from 98.6 F
, release of fever-inducing molecules called pyrogens that are released from infectious
agents (bacteria) or immune cells in response to trauma, infection, drug reactions and
brain tumors
physiological process that helps in providing innate immunity and may accompany the
inflammatory response
✔✔List the risk and benefits of fever - ✔✔benefits : inhibits replication of bacteria and
viruses, promotes interferon activity, increases activity of lymphocytes, and accelerates
tissue repair
risks : fevers -103-104 changes in metabolic pathways and denaturation of body
proteins, seizure temp over 102, irreversible brain damage over 106 and death over 108
✔✔Describe the features of an antigen and what is meant by antigenic determinant -
✔✔a foreign substance that stimulates an immune response, usually a large and
complex molecule such as protein or polysaccharide
antigenic determinant: specific region of the antigen that antibodies or immune cell
receptors recognize and bind to
✔✔Explain immunogenicity and list attributes that affect it - ✔✔ability if an antigen to
provoke an immune response
affected by
-foreignness : immune system responds best to substances that are recognized as non-
self
-molecular size : larger = more immunogenic
-chemical complexity : proteins most immunogenic, lipids and nucleic acids weak
structural stability : molecules that maintain a stable-three dimensional structure are
more easily recognized by immune cells
-susceptibility to processing : antigens must be broken down by antigen-presenting cells
so fragments can be displayed to lymphocytes
-dose and route of exposure : ex injection, inhalation, ingestion and how much
✔✔Define a hapten and describe how haptens stimulate immune response - ✔✔a small
molecule that cannot by itself stimulate an immune response but can become
immunogenic when it attaches to a larger carrier molecule- usually a proton
stimulation :
1. attaches to carrier protein in body
2. hapten-carrier complex acts as a new antigen
3. antigen-presenting cells process the complex and present it to lymphocytes
4. The immune response produces antibodies against the hapten portion of the complex
5. Future exposure to the hapten can trigger an immune response, especially if it again
attaches to body proteins
✔✔Define receptors of both T lymphocytes and B lymphocytes - ✔✔TCR: recognize
antigen fragments presented by MHC molecules
BCR: recognize free, intact antigens directly
