Parasitism Flashcards
Define symbiosis
Umbrella concept for any type of association between two or more organisms.
Define mutualism
A highly interdependent association where the two associates cannot live without the other. (+/+)
Ex: Lichen
Define commensalism
One associate benefits but no harm or benefit on the other associate. (+/0)
Ex: Clown Fish and Sea anemone
Define Parasite
- A relationship between two unrelated organisms where one is the host and the other is a parasite. Parasite is getting a benefit.
- The parasite is physiologically or metabolically dependent on the host.
- If heavily infected, the host will die.
- The reproductive potential of the parasite exceeds that of their host.
(+/-)
How successful is parasitism?
Very, all animal groups have parasite members. 50% of all species are parasitic in some stage of life.
Define ectoparasite
A parasite that lives on the surface of its host.
Define endoparasite
A parasite that lives within the host.
Define mesoparasite
A parasite that penetrates external cavities,
Ex: External ear or cloaca
What is a Definitive host
The host in which the parasite reaches sexual maturity.
What is an intermediate host
The host where the parasite undergoes morphological or physiological changes.
What is a paratenic host
A host exclusively used to transport the parasite; optional.
What is a vector
The host that plays an active role in transmission. It can also be the definitive or intermediate host.
How have parasites played a role in micro evolution?
Parasites may have motivated sexual selection in other animals. Animals that have a better fitness and better genetics/resistance to disease and parasites are going to be selected for. As parasites evolve, so do the their hosts.
(Red Queen Hypothesis)
Explain a parasite’s “evolution-niche”
Once a parasitic association evolves. The parasite could radiate within the body of the host to make more niches and possibly create more species.
It also may be possible for a parasite to create it’s own niche by changing it’s environment.
A niche here is the description of the parasite’s requirements. Not the host’s.
What is parenchymatous or albuminous degeneration
Tissue damage characterized by swollen cells packed with albuminous, fatty granules, indistinct nuclei, or pale cytoplasm. Often seen in infected liver, cardiac muscle, and kidney cells.
