exam 4 new stuff Flashcards
Symbiosis
Protracted association of two different species.
Parasitism
Benefits the parasite, but negatively affects the host; + -
Microparasites
Parasites that are too small to be seen with the naked eye.
Macroparasites
Parasite is visible by the naked eye.
Ectoparasite
Parasite on the outside of the host organism.
Endoparasite
Parasite on the inside of the host organism (salmonella or hookworm).
Direct Transmission
Parasite moves directly from one host to another (ex: hookworm).
Indirect Transmission
Parasite requires an intermediate host to reach the definitive host where sexual reproduction can occur (ex: malaria- intermediate: mosquito definitive: human)
Definitive
When the parasite reaches sexual maturity in the host.
Intermediate hosts
Intermediate hosts - Increased chance of mortality due to modification of their phenotype that makes them more susceptible to predation.
Dilution effect
Dilution effect - In species with poor communities, each larval tick cohort tends to encounter many mice, which are high-quality hosts and highly competent reservoirs. By definition, the ticks encounter few alternative hosts, which tend to be poorer-quality hosts and poor reservoirs. The result is a high abundance and infection prevalence in the resulting nymphal cohort.
Commensalism
- Parasite benefits, but host is not affected; + 0
Mutualism
Mutualism - Both the parasite and the host benefit; + +
Endo symbiont
Endo symbiont - Attach on the inside of host organism (ex: hookworm)
Ecto symbiont
Ecto symbiont - Attach on the outside of host organism (ex:lamprey, head lice)
Food web
Food web: interlocking pattern formed by a series of interconnecting food chains
food chain
food chain: the movement of energy and nutrients from one feeding group of organisms to another in a series that begins with plants and ends with carnivores, detrital feeders, and decomposers
trophic level
trophic level: functional classification of organisms in an ecosystem according to feeding relationships, ranging from first level autotrophs through succeeding levels of herbivores and carnivores.
what are the three lvl for food web
basal, intermediate, and top
Basal
Basal: feed on no other species but are fed on by others
Intermediate
Intermediate: feed on other species and they are prey of other species
tropic lvl Top
Top: not subject to predators; they prey on intermediate and basal species
food chain length
food chain length: the length of any given food chain within the food web is measured as the number of links between a top predator and the base of the web
species richness
species richness: the number of species
As species richness increase what happens to link density and mean chain length?
they increase
Linkage density (L/S)
Linkage density (L/S): a measure of the average number of links per species in the food web