General Parasitology
Commensalism - answersA relationship between two organisms in which one organism
benefits and the other is unaffected
Mutualism - answersA relationship between two species in which both species benefit
+/+
Parasitism - answersA relationship between two organisms of different species where
one benefits and the other is harmed +/-
parasitoidism - answersa special type of parasitism where the parasite eventually kills
the host
infection - answersinvasion of the body by a pathogenic organism in which they can
multiply and cause disease
Ectoparasites - answersParasites that feed on external surface of host. Arachnids
(mites,ticks)/insects (fleas, lice, mosquito)
endoparasites - answersParasites that live within the body of their host. Helminths
(worms, trematoda, cestoda, nematoda)/Protozoa (amoebae, cilliates, flagelates,
sporozoa)/Arthropoda (rarely)
Who are the hosts? - answersVertebrates- warm blooded animals have all kinds of
parasites due to many body regions
Invertebrates-insects i.e.: bee tracheal mites, vector function (leishmania)
Plants- pine beetle
Co-evolution of parasites with host - answersParasites generally show:
-genetic reductions
-loss of functional organs/organelles
-new structures adapted to parasitic lifestyle
Trichomonas co-evolution - answersTrichomonas found in T. Rex and found today in
many birds and reptiles (divergent evolution)
divergent evolution - answerswhen two or more species sharing a common ancestor
become more different over time
, convergent evolution - answersProcess by which unrelated organisms independently
evolve similarities when adapting to similar environments
Monoxenous parasite - answersHigh host specificity
A parasite that lives in or on a single host during its life cycle.
-highly adapted to one host
-bound to host survival
-specialized to predictable resources
oligoxenous - answersModerate host specificity
Can live on a few different hosts
Polyxenic parasite - answersLow host specificity
Wide variety of hosts accepted
Implications of host specificity - answersCo-evolved host/parasite system
-certain mutual adjustments (tolerance)
-cause little damage to one another
-destruction of host=destruction of parasite
Spread to new host
-no mutual tolerance
-Higher pathogenic effects
-parasite may be limited in survival/replication
History of parasitology - answersAntiquity
-papyrus ebers (1550 BC) names human endo-/ecto- parasites
-Aristotle (350 BC) Identifies flat, cylindrical, and round worms
Middle Ages
-not much progress, necropsy prohibited
-Thomas Moufet (1634) thought worms in feces was the body purifying itself from a
disease
-Antoine van Leeuwenhoek (1674) discovers free living Protozoa with a microscope.
Modern times
-Louis Pasteur (1865) disproves spontaneous generation
-Smith & Killbourne (1883) discoveries Babesia bigemina
-Stoll (1928) first reports of parasite related immunity
-interest in veterinary parasitology after WWII
Prof. Asa A. Chandler (1946) - answers"...a parasitologist probably has to stick his nose
into more different fields of knowledge than any other kind of biologist"
host/parasite/migration/environment
Commensalism - answersA relationship between two organisms in which one organism
benefits and the other is unaffected
Mutualism - answersA relationship between two species in which both species benefit
+/+
Parasitism - answersA relationship between two organisms of different species where
one benefits and the other is harmed +/-
parasitoidism - answersa special type of parasitism where the parasite eventually kills
the host
infection - answersinvasion of the body by a pathogenic organism in which they can
multiply and cause disease
Ectoparasites - answersParasites that feed on external surface of host. Arachnids
(mites,ticks)/insects (fleas, lice, mosquito)
endoparasites - answersParasites that live within the body of their host. Helminths
(worms, trematoda, cestoda, nematoda)/Protozoa (amoebae, cilliates, flagelates,
sporozoa)/Arthropoda (rarely)
Who are the hosts? - answersVertebrates- warm blooded animals have all kinds of
parasites due to many body regions
Invertebrates-insects i.e.: bee tracheal mites, vector function (leishmania)
Plants- pine beetle
Co-evolution of parasites with host - answersParasites generally show:
-genetic reductions
-loss of functional organs/organelles
-new structures adapted to parasitic lifestyle
Trichomonas co-evolution - answersTrichomonas found in T. Rex and found today in
many birds and reptiles (divergent evolution)
divergent evolution - answerswhen two or more species sharing a common ancestor
become more different over time
, convergent evolution - answersProcess by which unrelated organisms independently
evolve similarities when adapting to similar environments
Monoxenous parasite - answersHigh host specificity
A parasite that lives in or on a single host during its life cycle.
-highly adapted to one host
-bound to host survival
-specialized to predictable resources
oligoxenous - answersModerate host specificity
Can live on a few different hosts
Polyxenic parasite - answersLow host specificity
Wide variety of hosts accepted
Implications of host specificity - answersCo-evolved host/parasite system
-certain mutual adjustments (tolerance)
-cause little damage to one another
-destruction of host=destruction of parasite
Spread to new host
-no mutual tolerance
-Higher pathogenic effects
-parasite may be limited in survival/replication
History of parasitology - answersAntiquity
-papyrus ebers (1550 BC) names human endo-/ecto- parasites
-Aristotle (350 BC) Identifies flat, cylindrical, and round worms
Middle Ages
-not much progress, necropsy prohibited
-Thomas Moufet (1634) thought worms in feces was the body purifying itself from a
disease
-Antoine van Leeuwenhoek (1674) discovers free living Protozoa with a microscope.
Modern times
-Louis Pasteur (1865) disproves spontaneous generation
-Smith & Killbourne (1883) discoveries Babesia bigemina
-Stoll (1928) first reports of parasite related immunity
-interest in veterinary parasitology after WWII
Prof. Asa A. Chandler (1946) - answers"...a parasitologist probably has to stick his nose
into more different fields of knowledge than any other kind of biologist"
host/parasite/migration/environment
