mutualism Flashcards
what type of relationship is parasitism?
a symbiotic relationship where one species benefits from the other species which is harmed
how do parasites increase their fitness?
exploiting host organism for food, habitat, and dispersal
(t/f) parasites kill their host
false - they may die from secondary infection or suffer reduced fitness
what is cleptoparatism
parasitism by theft - form of feeding where one animal appropriates food gathered by the host
define infection and outcome
heavy load of parasites & outcome is a disease
parasites are distinguished by ____
size
define microparasite
viruses, bacteria, and protozoans that have short generations time, small in size, and develop and multiply rapidly. their transmission is often direct (host -> host)
define macroparasites
parasitic worms, lice, and fungi that have long generation time, spread by indirect or direct contact (may involve intermediate host or vectors), and do not complete their entire life in a single host
how do parasitic plants work?
they have a modified root (haustorium) that penetrates and connects to the vascular tissues (xylem/phloem) of the host plant
define hemiparasite
parasitic plant that contains chlorophyll and is therefore capable of photosynthesis - can obtain nutrients by connecting to the host xylem
define holoparasite
parasitic plant that does not contain chlorophyll and therefore cannot photosynthesis - obtains nutrients by connecting to host xylem and phloem because it cannot live without host plant
define ectoparasite
parasite that lives on the host skin - within protective covers of feathers and hair
define endoparasite
parasite that lives within the host - some burrow beneath the skin, heart, liver, etc…
(t/f) parasites of plants can divide up the habitat
true - some can live on leaves or root and the host serves as a habitat enabling survival & reproduction
what is the major problem for parasites?
gaining access to and escaping host
what is direct transmission?
it occurs when a parasite is transferred from one host to another without the involvement of an intermediate organism
how can direct transmission occur?
with a carrier, or the parasite can be disperse from one host to another through air, water, or other substrate
the transmission of malaria parasite is an example of transmission with?
intermediate vector
some parasites are transmitted between hosts by means of other organisms called?
vectors
define intermediate host
host that harbors a developmental phase of a parasite
give 2 examples of the defense mechanism of a host
a. behavioral - grooming
b. immune response - rxn inducing wbc to attack infection
parasitic infection functions to?
reduce growth & reproduction
define commensalism
relationship where one species benefits without affecting the other
define mutualism
both species benefit - growth, survival, or reproduction in enhanced for both
define symbiotic mutualism
individuals coexist - obligatory relationship
define nonsymbiotic mutualism
2 organisms do not physically coexist
explain the corals and crabs experiment
a. the success of corals on temperature reefs derives from their ability to harbor the symbiotic relationship it has with herbivorous crabs that mediate competition with seaweed
b. the coral protects the crab and the crab enhances coral growth and survival
c. by reducing overgrowth, crab increases coral growth, crab increases coral survival
define parasite
relationship where one species benefits from a prolonged, close association w/ another organism which is harmed
intermediate vs definite host
intermediate harbors parasite that is at larval stage while definite harbors adult parasite and reproduces
give an example of how host responds to paratism
killfish - their behavior is modified by infection and fitness is negatively affected
explain the experiment of freshwater mussles
dependent on a fish host, glochidia attaches to adult fish and there are ways to lure them or some conglutinate glochidia
define facultative mutualism
occurs when species can manage without mutualistic relationship
define obligate mutualism
occurs when they cannot exist without the mutualistic relationship
(t/f) mutualism is not as common as exploitation
true
mutualism has ____ mechanisms
dispersal
explains ants & acacia trees (janzen) experiment
a. trees provide shelter & rewards for ant species and then trees receive protection from herbivores
b. percentage of survival was higher with ants versus without (termites)
c. shouts with insects was higher when they were no ants versus when there were ants
plant roots are largely ____
fungi
