MICR 3230 MIDTERM Exam Questions
with Solved Rationales 2026-2027 Set.
immunity - Answer state of protection against foreign pathogens or substances (antigens)
can generate immunity without inducing disease (through vaccine)
herd immunity - Answer acquiring protective immunity in a critical mass of people through
vaccination or recovery from infection
serves as a buffer for everyone else
humoral immunity - Answer soluble proteins for labelling and destruction of invaders
combats pathogens via antibodies produced by B cells
cell mediated immunity - Answer cells that recognize and kill or engulf pathogen
involves primarily T cells
eradicate pathogens, clear infected self cells, or aid other cells in inducing immunity
important concepts for understanding the mammalian immune response - Answer humoral
and cell mediated immunity relies on surface receptors (B and T cell receptors)
receptors are randomly generated by gene segment rearrangements in B and T cells
B cells that encounter an antigen produce an antibody specific to the antigen
T cell receptors bind antigens or specific peptides presented by antigen presenting cells
4 main categories of pathogens - Answer viruses
bacteria
fungi
parasites
,pathogen recognition - Answer interaction bw foreign organisms and recognition molecule
expressed by host cells
ligands - Answer include whole pathogens, antigenic fragments of pathogens, or products
secreted by foreign organisms
ligand binding outcome - Answer extra or intra cellular cascade of events leading to labelling
and destruction of pathogen (immune response)
immune response relies on - Answer recognition molecules
- encoded in genomic DNA and always expressed
- PRRs which bind to PAMPs
- randomly generated (B and T cell receptors)
colonial selection and generation of diversity - Answer individual B and T cells each have an
individual specificity for a single antigen
- due to each cell having many copies of a receptor on the surface that only binds to one type
of antigen
when a B or T cell interacts w its specific antigen, it is selected and becomes activated
- activation results in proliferation, producing a large # of clones
- each clone is reactive against the antigen that initially stimulated the original lymphocyte
tolerance - Answer ensures that the immune system avoids destroying host tissue (self/non-
self discrimination)
many of the random rearrangements used to create B and T cell receptors could be anti-self
Tolerance helps to keep these anti-self recognition molecules/cells from circulating in the
bloodstream
self tolerance prohibits immune responses to host tissue maintained through elimination or
inhibition of cells
vertebrae immune system uses two interconnected systems: - Answer innate and adaptive
immunity
, innate immune response - Answer first line of defence
- fast but non specific
uses inherited recognition molecules
also uses phagocytic cells
adaptive immune response - Answer humoral and cell mediated responses
- using B and T lymphocytes
- slower to develop (5-6 days or more)
- use randomly generated antigen receptors
- highly specific to individual antigen molecules
innate and adaptive immune systems both work... - Answer cooperatively
activation of innate immune response produce signal molecules (cytokines, chemokines)
signal molecules stimulate and direct adaptive immune responses
memory - Answer hallmark of adaptive immunity
primary response is initiated upon first exposure to an antigen
- memory lymphocytes are left behind after antigen is cleared
secondary response is initiated upon secondary exposure to the same antigen that stimulate
memory lymphocytes
- stimulation yields faster, more significant, better response
memory is NOT present in innate immunity
-e.g., macrophage will not remember that its seen the antigen before
dysfunction of immunity: 2 broad categories - Answer overly active or misdirected immune
responses
immunodeficiency
with Solved Rationales 2026-2027 Set.
immunity - Answer state of protection against foreign pathogens or substances (antigens)
can generate immunity without inducing disease (through vaccine)
herd immunity - Answer acquiring protective immunity in a critical mass of people through
vaccination or recovery from infection
serves as a buffer for everyone else
humoral immunity - Answer soluble proteins for labelling and destruction of invaders
combats pathogens via antibodies produced by B cells
cell mediated immunity - Answer cells that recognize and kill or engulf pathogen
involves primarily T cells
eradicate pathogens, clear infected self cells, or aid other cells in inducing immunity
important concepts for understanding the mammalian immune response - Answer humoral
and cell mediated immunity relies on surface receptors (B and T cell receptors)
receptors are randomly generated by gene segment rearrangements in B and T cells
B cells that encounter an antigen produce an antibody specific to the antigen
T cell receptors bind antigens or specific peptides presented by antigen presenting cells
4 main categories of pathogens - Answer viruses
bacteria
fungi
parasites
,pathogen recognition - Answer interaction bw foreign organisms and recognition molecule
expressed by host cells
ligands - Answer include whole pathogens, antigenic fragments of pathogens, or products
secreted by foreign organisms
ligand binding outcome - Answer extra or intra cellular cascade of events leading to labelling
and destruction of pathogen (immune response)
immune response relies on - Answer recognition molecules
- encoded in genomic DNA and always expressed
- PRRs which bind to PAMPs
- randomly generated (B and T cell receptors)
colonial selection and generation of diversity - Answer individual B and T cells each have an
individual specificity for a single antigen
- due to each cell having many copies of a receptor on the surface that only binds to one type
of antigen
when a B or T cell interacts w its specific antigen, it is selected and becomes activated
- activation results in proliferation, producing a large # of clones
- each clone is reactive against the antigen that initially stimulated the original lymphocyte
tolerance - Answer ensures that the immune system avoids destroying host tissue (self/non-
self discrimination)
many of the random rearrangements used to create B and T cell receptors could be anti-self
Tolerance helps to keep these anti-self recognition molecules/cells from circulating in the
bloodstream
self tolerance prohibits immune responses to host tissue maintained through elimination or
inhibition of cells
vertebrae immune system uses two interconnected systems: - Answer innate and adaptive
immunity
, innate immune response - Answer first line of defence
- fast but non specific
uses inherited recognition molecules
also uses phagocytic cells
adaptive immune response - Answer humoral and cell mediated responses
- using B and T lymphocytes
- slower to develop (5-6 days or more)
- use randomly generated antigen receptors
- highly specific to individual antigen molecules
innate and adaptive immune systems both work... - Answer cooperatively
activation of innate immune response produce signal molecules (cytokines, chemokines)
signal molecules stimulate and direct adaptive immune responses
memory - Answer hallmark of adaptive immunity
primary response is initiated upon first exposure to an antigen
- memory lymphocytes are left behind after antigen is cleared
secondary response is initiated upon secondary exposure to the same antigen that stimulate
memory lymphocytes
- stimulation yields faster, more significant, better response
memory is NOT present in innate immunity
-e.g., macrophage will not remember that its seen the antigen before
dysfunction of immunity: 2 broad categories - Answer overly active or misdirected immune
responses
immunodeficiency
