Exam 3

Question 1

inquilinism

Answer 1

when one organism uses another for its residence

Question 2

interference competition

Answer 2

involves direct interactions between individuals, aggressive defense of territories, producing chemical toxins that harm potential competitors, or reducing the competitor’s access to resources

Question 3

resource/exploitive competition

Answer 3

competition involving the use of such limited resources

Question 4

niche partitioning

Answer 4

an evolutionary process whereby organisms decrease direct competition by differentiating in their use of resources by altering which, how, or when resources are used

Question 5

priority effect

Answer 5

a situation in which a species establishing itself in greater numbers in a place before the establishment of potential competitors wins in competition with species arriving later

Question 6

character displacement

Answer 6

the circumstances in which two species differ more from each other in geographic areas where they occur together than where their distributions do not overlap

Question 7

predators

Answer 7

kills and consume other organisms

Question 8

parasites

Answer 8

live on the tissues of their host, often reducing the fitness of the host, but not generally killing it

Question 9

parasitoid

Answer 9

an insect whose larva consumes its host and kills it in the process

Question 10

pathogens

Answer 10

induce disease, a debilitating condition, in their hosts

Question 11

refuges

Answer 11

situations in which members of an exploited population have some protection from predators and parasites

Question 12

predator satiation

Answer 12

when prey reduce their individual probability of being eaten by occurring at very high densities

Question 13

mutualism

Answer 13

interactions between individuals of different species that benefit both partners

Question 14

commensalism

Answer 14

an interaction between two species benefits one of them, while the other is neither benefited nor harmed

Question 15

facultative mutualism

Answer 15

when some species can live without their mutualistic partners

Question 16

obligate mutualism

Answer 16

species are so dependent on the mutualistic relationship that they cannot live in its absence

Question 17

arbuscular mycorrhizae

Answer 17

mycorrhizal fungus produces arbuscules, hyphae, vesicles, and ectomycorrhizae

Question 18

arbuscules

Answer 18

sites of exchange between plant and fungus

Question 19

hyphae

Answer 19

fungal filaments

Question 20

vesicles

Answer 20

fungal energy storage organs within root cortex cells

Question 21

ectomycorrhizae

Answer 21

the fungus forms a mantle around roots and a netlike structure around root cells

Question 22

community

Answer 22

a association of interacting species inhabiting some defined area

Question 23

lognormal distribution

Answer 23

log intervals reveal a bell shaped curve

Question 24

species rarefaction curve

Answer 24

defines the number of samples needed to likely record all or almost all species at your location of interest or estimate actual species count

Question 25

species diversity

Answer 25

defined by species richness and evenness

Question 26

species richness

Answer 26

the number of species in the community

Question 27

species evenness

Answer 27

the relative abundance of species in communities

Question 28

equilibrium

Answer 28

when conditions remain more or less stable

Question 29

intermediate disturbance hypothesis

Answer 29

predicts that intermediate levels of disturbance promote higher levels of diversity

Question 30

disturbacne

Answer 30

a discrete event that removes individuals or biomass and creates space for new individuals to become established

Question 31

keystone species

Answer 31

a species that has inordinate influences or community structure

Question 32

strong interactions

Answer 32

the feeding activities of a few species have dominant influence on community structure

Question 33

foundation/dominant species

Answer 33

species that have substantial influences on other species without involvement of an intermediary species

Question 34

indirect interactions

Answer 34

one species affects another through a third, intermediary species

Question 35

indirect commensalism

Answer 35

activities of one species indirectly benefit another species (through an intermediary species) without itself being helped or harmed

Question 36

apparent competition

Answer 36

negative impacts are the results of two species sharing a predator/herbivore or by one species facilitating populations of a predator/herbivore of the second species

Question 37

primary production

Answer 37

production of new organic matter, or biomass, by autotrophs in an ecosystem per unit of area or volume and per unit of time

Question 38

gross primary production

Answer 38

the total primary production by all primary producers in the ecosystem

Question 39

net primary production

Answer 39

gross primary production minus respiration by primary producers; it is the amount of energy in the form of biomass available to the consumers in an ecosystem

Question 40

secondary production

Answer 40

the production of biomass by heterotrophic consumer organisms feeding on plants, animals, microbes, fungi, or detritus during some period of time, for example, per hour or per year

Question 41

trophic level

Answer 41

a position in a food web and is determined by the number of transfers of energy from primary producers to that level

Question 42

bottom-up controls

Answer 42

influences of physical and chemical factors on ecosystems, such as temperature and nutrients

Question 43

top-down controls

Answer 43

influences of consumers on ecosystems

Question 44

trophic cascade

Answer 44

effects of predators on prey that alter abundance, biomass, or productivity of a population, community, or trophic level across more than one link in the food web

Question 45

trophic dynamics

Answer 45

transfer of energy from one part of an ecosystem to another

Question 46

tri-trophic interactions

Answer 46

three levels to dynamics: plants, herbivores, and consumers of herbivores