Parasitology~ EXAM 1 and answers
1. Protozoa
2. Helminths (worms)
3. Arthropods (fleas, ticks, etc.)✔✔What are the three organisms that are considered
parasites?
Parasitism✔✔Relationship between host and parasite; in or on host and is taking
nutrients or blood or other substances from host.
Hyperparasitism✔✔when a parasite is a host to another parasite
Pinworms
Giardiasis
Dog roundworms
Ticks✔✔what are some common parasites in the United States?
Travel
Immigration and Emigration✔✔______ transfers many parasites into the United
States.
visceral✔✔pertaining to organs
cutaneous✔✔pertaining to skin
Every animal and most plants contain at least one parasite✔✔How common are
parasites?
100% of organisms can be a host to a parasite.✔✔What percentage of organisms
can be hosts?
50% of organisms can be parasites
80% of organisms including bacteria can be parasites✔✔What percentage of
organisms are parasites?
What percentage of organisms including bacteria can be parasites?
370 species✔✔How many species can be parasites to humans?
Bacteria
Fungi
Plants
Protozoa
Animals✔✔What major groups of organisms are parasites found in?
symbiosis✔✔"living closely together", close relationship between two organisms
symbionts✔✔interacting organisms
,Phoresis✔✔travelling together; neither benefit or lose from the interaction.
Commensalism✔✔Relationship where one member benefits, other is unaffected
mutualism✔✔relationship where both members benefit
Parasitism✔✔a relationship where one member gains (parasite), and the other is
negatively (host) affected
slower population growth✔✔A larger organism results in .....
SImilarities:
-Both have (+,-) relationship
-
Differences
-Predator is larger than prey
-Parasite is smaller than host
-Predators have slower growth than prey population
-Parasite population size increases faster than the host population.
-Predator eats many prey
-Parasite uses 4 or less hosts to complete a generation (often very specific
interactions are involved)✔✔What are the similarities and differences between
predator and parasite relationships?
Mosquitoes, ticks, leeches, etc. are predators. They prey on many hosts or single
host intermittently.✔✔Give some examples of micropredators or intermittent
parasites.
Wasps and flies
adults are free-living
immature stages feed on hosts body (usually another insect)✔✔Give some
examples of parasitoids.
Ectoparasites✔✔Parasites that live on the body surface of host
Endoparasites✔✔Parasites that live on the inside of the body of the host
obligate parasites✔✔parasites that needs a host to survive
Facultative parasite✔✔parasites that normally free-living organisms that may
become parasitic.
The infection is usually fatal
accidental or incidental parasite✔✔parasites in the wrong host. In this case the
parasite does not usually survive
permanent parasite✔✔parasite that lives its entire life or life stage on or in one host
, temporary parasite✔✔a parasite that lives in or on several hosts during a life-cycle
stage
zoonotic parasite✔✔a parasite that normally develops in other animals, but can
infect humans
Definitive Host✔✔a host where the parasite reaches sexual maturity, or where the
parasite is most detrimental to humans
Intermediate host✔✔a required host, but maturity (sexual) does not occur here.
Usually asexual reproduction happens here
vector✔✔transmits parasite from one host to another
Paratenic Host✔✔parasite DOES NOT DEVELOP here, but remains infective to
another host
Example: Mammal Tapeworm
Mammal (definitive host) ->
crustacean (1st Intermediate host) ->
1st Fish (2nd Intermediate host)->
2nd Fish (Paratenic Host (No development))->
Mammal (definitive host)✔✔Give an example that shows a definitive host, two
intermediate hosts, and a paratenic host.
Reservoir Hosts (Zoonotic Hosts)✔✔a host that harbors an infection that can be
transmitted to humans. It may be normal hosts for non-specific parasites
Example: Rat Schistosome
human (definitive host)->
snail (1st intermediate host and vector)->
human or rat (reservoir host)->
snail....->✔✔Give an example that includes a reservoir host, two intermediate hosts,
a vector host, and a definitive host
parasite's development and transmission mode✔✔What do parasite life cycles
describe?
Monoxenous Life Cycle (direct)✔✔parasites complete life cycle within a single host.
The infective stage enters the host and the same stage leaves the host.
Heteroxenous Life Cycle (complex)✔✔the parasite requires several hosts to
complete its life cycle. This stage entering host differs from the stage leaving the
host.
Environments
1. Protozoa
2. Helminths (worms)
3. Arthropods (fleas, ticks, etc.)✔✔What are the three organisms that are considered
parasites?
Parasitism✔✔Relationship between host and parasite; in or on host and is taking
nutrients or blood or other substances from host.
Hyperparasitism✔✔when a parasite is a host to another parasite
Pinworms
Giardiasis
Dog roundworms
Ticks✔✔what are some common parasites in the United States?
Travel
Immigration and Emigration✔✔______ transfers many parasites into the United
States.
visceral✔✔pertaining to organs
cutaneous✔✔pertaining to skin
Every animal and most plants contain at least one parasite✔✔How common are
parasites?
100% of organisms can be a host to a parasite.✔✔What percentage of organisms
can be hosts?
50% of organisms can be parasites
80% of organisms including bacteria can be parasites✔✔What percentage of
organisms are parasites?
What percentage of organisms including bacteria can be parasites?
370 species✔✔How many species can be parasites to humans?
Bacteria
Fungi
Plants
Protozoa
Animals✔✔What major groups of organisms are parasites found in?
symbiosis✔✔"living closely together", close relationship between two organisms
symbionts✔✔interacting organisms
,Phoresis✔✔travelling together; neither benefit or lose from the interaction.
Commensalism✔✔Relationship where one member benefits, other is unaffected
mutualism✔✔relationship where both members benefit
Parasitism✔✔a relationship where one member gains (parasite), and the other is
negatively (host) affected
slower population growth✔✔A larger organism results in .....
SImilarities:
-Both have (+,-) relationship
-
Differences
-Predator is larger than prey
-Parasite is smaller than host
-Predators have slower growth than prey population
-Parasite population size increases faster than the host population.
-Predator eats many prey
-Parasite uses 4 or less hosts to complete a generation (often very specific
interactions are involved)✔✔What are the similarities and differences between
predator and parasite relationships?
Mosquitoes, ticks, leeches, etc. are predators. They prey on many hosts or single
host intermittently.✔✔Give some examples of micropredators or intermittent
parasites.
Wasps and flies
adults are free-living
immature stages feed on hosts body (usually another insect)✔✔Give some
examples of parasitoids.
Ectoparasites✔✔Parasites that live on the body surface of host
Endoparasites✔✔Parasites that live on the inside of the body of the host
obligate parasites✔✔parasites that needs a host to survive
Facultative parasite✔✔parasites that normally free-living organisms that may
become parasitic.
The infection is usually fatal
accidental or incidental parasite✔✔parasites in the wrong host. In this case the
parasite does not usually survive
permanent parasite✔✔parasite that lives its entire life or life stage on or in one host
, temporary parasite✔✔a parasite that lives in or on several hosts during a life-cycle
stage
zoonotic parasite✔✔a parasite that normally develops in other animals, but can
infect humans
Definitive Host✔✔a host where the parasite reaches sexual maturity, or where the
parasite is most detrimental to humans
Intermediate host✔✔a required host, but maturity (sexual) does not occur here.
Usually asexual reproduction happens here
vector✔✔transmits parasite from one host to another
Paratenic Host✔✔parasite DOES NOT DEVELOP here, but remains infective to
another host
Example: Mammal Tapeworm
Mammal (definitive host) ->
crustacean (1st Intermediate host) ->
1st Fish (2nd Intermediate host)->
2nd Fish (Paratenic Host (No development))->
Mammal (definitive host)✔✔Give an example that shows a definitive host, two
intermediate hosts, and a paratenic host.
Reservoir Hosts (Zoonotic Hosts)✔✔a host that harbors an infection that can be
transmitted to humans. It may be normal hosts for non-specific parasites
Example: Rat Schistosome
human (definitive host)->
snail (1st intermediate host and vector)->
human or rat (reservoir host)->
snail....->✔✔Give an example that includes a reservoir host, two intermediate hosts,
a vector host, and a definitive host
parasite's development and transmission mode✔✔What do parasite life cycles
describe?
Monoxenous Life Cycle (direct)✔✔parasites complete life cycle within a single host.
The infective stage enters the host and the same stage leaves the host.
Heteroxenous Life Cycle (complex)✔✔the parasite requires several hosts to
complete its life cycle. This stage entering host differs from the stage leaving the
host.
Environments
