2.5a,b,c - Parasitism - Niche, Parasite Life Cycle, Transmission and Virulence Flashcards
Define parasitic niche
A symbiotic interaction between a parasite and its host.
Define parasitism
A parasite gains benefit in terms of nutrients at the expense of its host
Define commensalism
When one species benefits from living off of another species but the other species is unaffected
Define mutualism
When both species benefit by association
Define the fundamental niche
A niche that a species occupies in the absence of any interspecific competition
Define the realised niche
A niche that is occupied in response to interspecific competition
Define resource partitioning
Resource partitioning is where the realised niches are sufficiently different, potential competitors can co-exist
Define a facultative parasite
Facultative parasites are parasites that are able to live without a host
Define obligate parasite
Obligate parasites are parasites that must live with their host
Define ectoparasite
A parasite that lives on the surface of their host
Define endoparasite
A parasite that lives inside their host
Define a definitive host
A definitive host is the host where the parasite reaches sexual maturity
Define an intermediate host
An intermediate host is the host where the parasite lives for part of its life cycle.
Define a vector
A vector transfers a parasite from host to host (it may also, but not always, be a host for part of the parasite’s life cycle)
Define transmission
Transmission is the spread of a parasite to a host
Define virulence
Virulence is the harm caused to a host species by a parasite
Define macroparasites
Multicellular parasites, often larger
Define microparasites
Smaller parasites, often unicellular
What is an ecological niche?
the range of resources and conditions allowing the species to maintain a viable population.
Why do parasites have a narrow (specialised) niche?
Parasites are very host-specific
What are some examples of factors that increase the rate of transmission and virulence?
Host to host (direct or indirect), host behaviour, host systems (immune, reproductive etc)
What is an extended phenotype?
Extended phenotype is the alterations of host behavior.
What are examples of extended phenotypes with parasites?
Rabies virus makes the host more aggressive
Define competitive exclusion
Competitive exclusion can occur, where the niches
of two species are so similar that one declines to local extinction due to interspecific competition
