NSG 520 UNIT 2 EXAM QUESTIONS AND
ANSWERS. VERIFIED 2026.
Symbiosis - ANS Benefits only the human; no harm to the microorganism
Mutualism - ANS Benefits the human and the microorganism
Commenaslism - ANS Benefits only the microorganism; no harm to the human
Pathogenicity - ANS Benefits only the microorganism; no harm to the human
Opportunism - ANS A situation in which benign microorganisms become pathogenic because
of decreased human host resistance, increase in numbers, or translocation to other body sites
Communicability - ANS The ability to spread from one individual to others and cause disease
Immunogenicity - ANS The ability to induce an immune response
Infectivity - ANS The ability to invade and multiply in the host
Mechanism of action - ANS How the microorganism damages tissue
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,Pathogenicity - ANS The ability to produce disease: success depends on communicability,
infectivity, extent of tissue damage, and virulence
Portal of entry - ANS The route by which a microorganism infects the host
Toxigenicity - ANS The ability to produce soluble toxins or endotoxins, factors that greatly
influence the degree of virulence
Virulence - ANS The capacity to cause severe disease
Overgrowth of benign microorganism to become pathogenic - ANS Overgrowth of benign
microorganism to become pathogenic
Which outcome would be produced by a symbiotic microorganism? - ANS Prevention of
growth of pathogenic microorganisms
The process of infection - ANS 1. Encounter (contact) and transmission
2. Colonization
3. Invasion
4. Dissemination
5. Cellular or tissue damage
Encounter and Transmission - ANS Endogenous microorganisms: present in the body
Exogenous microorganisms: transmitted from an external source, like contaminated water
Direct transmission - ANS occurs through direct contact with infections of another individual
ex. staph and STIs
Indirect transmission - ANS occurs from contact with fomites, or from respiratory, fecal oral,
or vector-borne transmission
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, fomite serves as a mechanism for transfer between hosts
Respiratory transmission - ANS Coughing or sneezing creates a mist that can be inhaled from
the air for considerable time
Infected individuals also produce airborne droplets that settle on environmental surfaces
Fecal-oral transmission - ANS It occurs when contaminated food or water is ingested
ex. Salmonella, cholera, Hepatitis A
Vector-borne transmission - ANS It occurs when an infectious agent undergoes part of its life
cycle within an insect that feeds off the blood of infected animals or humans
ex. malaria, lyme disease
Horizontal transmission - ANS transmitted from one person to another through exposure to
blood and body fluids or zoonotic infections directly transmitted from animals
ex. HIV, toxoplasmosis
Vertical transmission - ANS transmitted from mother to child across the placenta, during
delivery from the birth canal, or from breast milk
ex. listeria, chlamydia, staph
Colonization - ANS The ability of a pathogenic microorganism to survive and multiply on or
within the human environment
- Adherence is a part of the colonization process and helps protect the microorganism from
removal
- specificity of these receptors results in localization of an infectious agent to particular sites
Invasion or Penetration - ANS The ability of pathogens to cross surface barriers, including the
skin and mucous membranes.
This involves penetration or a break in the integrity of the barrier
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS. VERIFIED 2026.
Symbiosis - ANS Benefits only the human; no harm to the microorganism
Mutualism - ANS Benefits the human and the microorganism
Commenaslism - ANS Benefits only the microorganism; no harm to the human
Pathogenicity - ANS Benefits only the microorganism; no harm to the human
Opportunism - ANS A situation in which benign microorganisms become pathogenic because
of decreased human host resistance, increase in numbers, or translocation to other body sites
Communicability - ANS The ability to spread from one individual to others and cause disease
Immunogenicity - ANS The ability to induce an immune response
Infectivity - ANS The ability to invade and multiply in the host
Mechanism of action - ANS How the microorganism damages tissue
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Pathogenicity - ANS The ability to produce disease: success depends on communicability,
infectivity, extent of tissue damage, and virulence
Portal of entry - ANS The route by which a microorganism infects the host
Toxigenicity - ANS The ability to produce soluble toxins or endotoxins, factors that greatly
influence the degree of virulence
Virulence - ANS The capacity to cause severe disease
Overgrowth of benign microorganism to become pathogenic - ANS Overgrowth of benign
microorganism to become pathogenic
Which outcome would be produced by a symbiotic microorganism? - ANS Prevention of
growth of pathogenic microorganisms
The process of infection - ANS 1. Encounter (contact) and transmission
2. Colonization
3. Invasion
4. Dissemination
5. Cellular or tissue damage
Encounter and Transmission - ANS Endogenous microorganisms: present in the body
Exogenous microorganisms: transmitted from an external source, like contaminated water
Direct transmission - ANS occurs through direct contact with infections of another individual
ex. staph and STIs
Indirect transmission - ANS occurs from contact with fomites, or from respiratory, fecal oral,
or vector-borne transmission
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, fomite serves as a mechanism for transfer between hosts
Respiratory transmission - ANS Coughing or sneezing creates a mist that can be inhaled from
the air for considerable time
Infected individuals also produce airborne droplets that settle on environmental surfaces
Fecal-oral transmission - ANS It occurs when contaminated food or water is ingested
ex. Salmonella, cholera, Hepatitis A
Vector-borne transmission - ANS It occurs when an infectious agent undergoes part of its life
cycle within an insect that feeds off the blood of infected animals or humans
ex. malaria, lyme disease
Horizontal transmission - ANS transmitted from one person to another through exposure to
blood and body fluids or zoonotic infections directly transmitted from animals
ex. HIV, toxoplasmosis
Vertical transmission - ANS transmitted from mother to child across the placenta, during
delivery from the birth canal, or from breast milk
ex. listeria, chlamydia, staph
Colonization - ANS The ability of a pathogenic microorganism to survive and multiply on or
within the human environment
- Adherence is a part of the colonization process and helps protect the microorganism from
removal
- specificity of these receptors results in localization of an infectious agent to particular sites
Invasion or Penetration - ANS The ability of pathogens to cross surface barriers, including the
skin and mucous membranes.
This involves penetration or a break in the integrity of the barrier
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
