MIC 102 REVISION EXAM 2025/2026 QUESTIONS AND
ANSWERS GRADED A+
✔✔Innate Immune System - ✔✔Present from birth
✔✔Examples of Innate Immune System - ✔✔1. Physical Defenses (skin)
2. Chemicals (pH)
3. Communities (microbial communities)
4. Immune Cells (look for foreign microbes)
✔✔Adaptive Immune System - ✔✔Having the ability to adapt
✔✔Examples of Adaptive Immune System - ✔✔1. Memory from exposure
2. Specialized Cells
✔✔Physical Barriers - ✔✔1. Cell junctions (hard to squeeze through)
2. Hair (facilitate movement of immune cells)
3. Mucous (microbes stick)
4. Waste (move microbes out of system)
✔✔Sebum - ✔✔Lipid sealant that creates a semi penetrable barrier
✔✔How does sebum help protect against microbes? - ✔✔Microbes metabolize the
sebum and produce fatty acids as a bi-product which makes skin acidic killing/inhibiting
growth other microbes
✔✔Lysozyme - ✔✔Cleave bonds that link peptidoglycan (bacteria) and chitin (fungi)
together
✔✔Why can lysozymes cleave both chitin and peptidoglycan? - ✔✔Very similar
structure so lysozymes are able to recognize both
✔✔Memory from Exposure Stages - ✔✔1. Initial Exposure
2. Primary Immune Response
3. Secondary Exposure
4. Secondary Immune Response
✔✔Initial Exposure - ✔✔First time exposed (no response)
✔✔Primary Immune Response - ✔✔Starts to produce some antibodies that are specific
to pathogen
✔✔Secondary Exposure - ✔✔A second exposure to the same infective agent (has
decreases because why make something that is not being used)
, ✔✔Secondary Immune Response - ✔✔Larger and faster response compared to first
time (concentration of antibodies will be sustained at a larger concentration
✔✔Physical Barries - ✔✔1. Cell Junction
2. Hair
✔✔Cell Junction/ Tight Junctions - ✔✔Like a filter which makes it tough for microbes to
squeeze through between cells
✔✔Skin - ✔✔Epitheal Cell and constantly regenerating
✔✔Hair - ✔✔Helps with aggregation (grouping)
✔✔Mucous - ✔✔1. Found in most of our 'tubes' directly exposed to the environment
2. Sticky/ Polysaccharide groop
3.Moves microbes away from body
✔✔Waste - ✔✔Physical ways to remove pathogens from our tubes
✔✔Sebum - ✔✔1.Lipid sealant (waxy)
2.Creates a semi-penitrable barriers
3. Other microbes lives off the sebum which releases fatty acids making acidic
(decreased pH) environment which kills other microbes
✔✔What is a common regulatory of microbial communities? - ✔✔pH
✔✔Lysozyme - ✔✔Cleaves bonds that like peptidoglycan together cleaves bonds
between chitin together (fungus) which makes the cell wall destable
✔✔AMP - ✔✔Antimicrobial Peptides to help degrade pathogens (lysozymes)
✔✔Gut Microbiome - ✔✔1. Mouth to Anus
2. pH and O2 levels change
3. Microbial Community and densities change
✔✔Stomach - ✔✔pH: 1-3 (acidic)
O2: 77mmHg (aerobic respiration)
✔✔Duodenum - ✔✔pH: 6-7
O2: 33 mmHg
(anaerobic respiration)
ANSWERS GRADED A+
✔✔Innate Immune System - ✔✔Present from birth
✔✔Examples of Innate Immune System - ✔✔1. Physical Defenses (skin)
2. Chemicals (pH)
3. Communities (microbial communities)
4. Immune Cells (look for foreign microbes)
✔✔Adaptive Immune System - ✔✔Having the ability to adapt
✔✔Examples of Adaptive Immune System - ✔✔1. Memory from exposure
2. Specialized Cells
✔✔Physical Barriers - ✔✔1. Cell junctions (hard to squeeze through)
2. Hair (facilitate movement of immune cells)
3. Mucous (microbes stick)
4. Waste (move microbes out of system)
✔✔Sebum - ✔✔Lipid sealant that creates a semi penetrable barrier
✔✔How does sebum help protect against microbes? - ✔✔Microbes metabolize the
sebum and produce fatty acids as a bi-product which makes skin acidic killing/inhibiting
growth other microbes
✔✔Lysozyme - ✔✔Cleave bonds that link peptidoglycan (bacteria) and chitin (fungi)
together
✔✔Why can lysozymes cleave both chitin and peptidoglycan? - ✔✔Very similar
structure so lysozymes are able to recognize both
✔✔Memory from Exposure Stages - ✔✔1. Initial Exposure
2. Primary Immune Response
3. Secondary Exposure
4. Secondary Immune Response
✔✔Initial Exposure - ✔✔First time exposed (no response)
✔✔Primary Immune Response - ✔✔Starts to produce some antibodies that are specific
to pathogen
✔✔Secondary Exposure - ✔✔A second exposure to the same infective agent (has
decreases because why make something that is not being used)
, ✔✔Secondary Immune Response - ✔✔Larger and faster response compared to first
time (concentration of antibodies will be sustained at a larger concentration
✔✔Physical Barries - ✔✔1. Cell Junction
2. Hair
✔✔Cell Junction/ Tight Junctions - ✔✔Like a filter which makes it tough for microbes to
squeeze through between cells
✔✔Skin - ✔✔Epitheal Cell and constantly regenerating
✔✔Hair - ✔✔Helps with aggregation (grouping)
✔✔Mucous - ✔✔1. Found in most of our 'tubes' directly exposed to the environment
2. Sticky/ Polysaccharide groop
3.Moves microbes away from body
✔✔Waste - ✔✔Physical ways to remove pathogens from our tubes
✔✔Sebum - ✔✔1.Lipid sealant (waxy)
2.Creates a semi-penitrable barriers
3. Other microbes lives off the sebum which releases fatty acids making acidic
(decreased pH) environment which kills other microbes
✔✔What is a common regulatory of microbial communities? - ✔✔pH
✔✔Lysozyme - ✔✔Cleaves bonds that like peptidoglycan together cleaves bonds
between chitin together (fungus) which makes the cell wall destable
✔✔AMP - ✔✔Antimicrobial Peptides to help degrade pathogens (lysozymes)
✔✔Gut Microbiome - ✔✔1. Mouth to Anus
2. pH and O2 levels change
3. Microbial Community and densities change
✔✔Stomach - ✔✔pH: 1-3 (acidic)
O2: 77mmHg (aerobic respiration)
✔✔Duodenum - ✔✔pH: 6-7
O2: 33 mmHg
(anaerobic respiration)
