PLTW PRINCIPLES OF BIO-MEDICAL SCIENCES 3.1.3 EXAM WITH
CORRECT SOLUTIONS #14
What are some possible sources of infectious agents? Where can they be found? -
correct answer Feces, contaminated food/water, can be inhaled from the air,
contaminated medical equipment, donated organs, skin, and saliva.
Chain of infection - correct answer Agent of disease - Reservoir - Portal of exit - Mode
of Transmission - Portal of entry - Susceptible hosts
The bacterium, E. Coli, can cause food poisoning. It can spread from a reservoir (such
as contaminated beef) to a susceptible host. Is this type of transmission direct or
indirect? - correct answer It is transmitted in an indirect way.
What does the infectious dose tell you about how dangerous an organism is? - correct
answer The less the infectious dose is the more dangerous it is.
What is innate immunity? - correct answer An immunity that is naturally present (not
there because of an infection or vaccination where you build an immunity).
What is acquired immunity? - correct answer Where you build up an immunity (either
from an infection or a vaccination).
How do tears protect the body from infection? - correct answer They contain an enzyme
that kills invading organisms. Also washes out invaders.
How does nasal mucosa and cilia protect the body from infection? - correct answer Trap
invaders.
How do digestive enzymes protect the body from infection? - correct answer Help to kill
invaders.
How do cillia protect the body from infection? - correct answer Invaders get trapped and
get passed up and out. Smoking can affect how they work.
How do phagocytes protect the body from infection? - correct answer Eat and digest
invaders.
How does stomach acid protect the body from infection? - correct answer Has a ph of
around 2 and works to kill invaders.
How does normal flora protect the body from infection? - correct answer They live on
the skin and in the intestines. They take up space and let out chemicals to keep
invaders out and prevent them from attaching.
CORRECT SOLUTIONS #14
What are some possible sources of infectious agents? Where can they be found? -
correct answer Feces, contaminated food/water, can be inhaled from the air,
contaminated medical equipment, donated organs, skin, and saliva.
Chain of infection - correct answer Agent of disease - Reservoir - Portal of exit - Mode
of Transmission - Portal of entry - Susceptible hosts
The bacterium, E. Coli, can cause food poisoning. It can spread from a reservoir (such
as contaminated beef) to a susceptible host. Is this type of transmission direct or
indirect? - correct answer It is transmitted in an indirect way.
What does the infectious dose tell you about how dangerous an organism is? - correct
answer The less the infectious dose is the more dangerous it is.
What is innate immunity? - correct answer An immunity that is naturally present (not
there because of an infection or vaccination where you build an immunity).
What is acquired immunity? - correct answer Where you build up an immunity (either
from an infection or a vaccination).
How do tears protect the body from infection? - correct answer They contain an enzyme
that kills invading organisms. Also washes out invaders.
How does nasal mucosa and cilia protect the body from infection? - correct answer Trap
invaders.
How do digestive enzymes protect the body from infection? - correct answer Help to kill
invaders.
How do cillia protect the body from infection? - correct answer Invaders get trapped and
get passed up and out. Smoking can affect how they work.
How do phagocytes protect the body from infection? - correct answer Eat and digest
invaders.
How does stomach acid protect the body from infection? - correct answer Has a ph of
around 2 and works to kill invaders.
How does normal flora protect the body from infection? - correct answer They live on
the skin and in the intestines. They take up space and let out chemicals to keep
invaders out and prevent them from attaching.
