parasitism Flashcards
(22 cards)
what is an ecological niche?
a multidimensional summary of the tolerances and requirements of a species
how can a parasites niche be described?
narrow, specialised niche and are very host specific
what is the difference between a endoparasite and ectoparasite?
an ectoparasite lives on the surface of the host whereas an endoparasite lives within the tissues of a host
what is a fundamental niche?
a niche that occupies in the absence of any interspecific competition
what is a realised niche?
occupied in response to interspecific competition
what happens as a result of interspecific niche?
competitive exclusion
what is meant by competitive exclusion?
where the niches of two species are so similar that one declines to local extinction
what is meant by resource partitioning?
where the realised niches are sufficiently different, potential competitors can co-exist by resource partitioning
what is meant by the definitive host?
where the parasite reaches sexual maturity
what are viruses?
parasites that can only replicate inside the host cell
what is a viruses DNA/RNA packaged in?
a protective protein coat
what is around the outer surface of a virus?
antigens that the host cell may or may not be able to detect as foreign
what happens after the viruses attach to the host cell?
it becomes infected with their genetic material and the host cell with viral enzymes replicate the viral genome
what is meant by a retrovirus?
a virus which contains RNA rather than DNA
what is meant by virulence?
the deleterious effect that a parasite has on its host
what is a vector?
means of transmission of a parasite
defence against parasitic attack:
has both nonspecific and specific aspects
what is a physical barrier?
epithelial tissue blocks the entry of pathogens
what are chemical secretions?
hydrolytic enzymes in mucus, saliva and tears that destroy bacteria walls
what is an inflammatory response?
injured cells release signalling molecules that result in enhanced blood flow to the site, bringing antimicrobial proteins and phagocytes
what are phagocytes?
engulf pathogens into a vacuole and release powerful enzymes contained in lysosomes
