Chapter 53

Question 1

community

Answer 1

an interacting group of various species in a common location.

Question 2

host

Answer 2

an organism that harbors a parasitic, a mutual, or a commensal symbiont, typically providing nourishment and shelter.

Question 3

disturbance regime

Answer 3

a temporary change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements.

Question 4

competition

Answer 4

n interaction between organisms or species in which both the organisms or species are harmed. Limited supply of at least one resource (such as food, water, and territory) used by both can be a factor.

Question 5

predation

Answer 5

A form of symbiotic relationship between two organisms of unlike species in which one of them acts as predator that captures and feeds on the other organism that serves as the prey.

Question 6

primary succession

Answer 6

occurs in essentially lifeless areas—regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier.

Question 7

coevolutionary arms race

Answer 7

a struggle between competing sets of co-evolving genes, traits, or species, that develop adaptations and counter-adaptations against each other

Question 8

predator

Answer 8

an organism which feeds on prey.

Question 9

secondary succession

Answer 9

a process started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil

Question 10

commensalisms

Answer 10

a relationship between individuals of two species in which one species obtains food or other benefits from the other without either harming or benefiting the latter.

Question 11

prey

Answer 11

an organism which gets fed on by predators.

Question 12

intraspecific competition

Answer 12

an interaction in population ecology, whereby members of the same species compete for limited resources. This leads to a reduction in fitness for both individuals.

Question 13

standing/constitutive

Answer 13

The total amount or weight, or energy content, of (a portion of) organisms existing in a specific area at a particular time.

Question 14

pioneering species

Answer 14

are hardy species which are the first to colonize previously disrupted or damaged ecosystems, beginning a chain of ecological succession that ultimately leads to a more biodiverse steady-state ecosystem.

Question 15

interspecific competition

Answer 15

a form of competition in which individuals of different species compete for the same resources in an ecosystem (e.g. food or living space). … If the resource cannot support both populations, then lowered fecundity, growth, or survival may result in at least one species.

Question 16

defenses

Answer 16

anatomical mechanisms that protect prey from predators.

Question 17

weed

Answer 17

Any plant that is growing in a place where a human wants a different kind of plant or no plants at all.

Question 18

niche differentiation

Answer 18

refers to the process by which competing species use the environment differently in a way that helps them to coexist.

Question 19

consumption

Answer 19

The using up of something, especially the rate at which it is used.

Question 20

high-productivity

Answer 20

refers to the rate of generation of biomass in an ecosystem. It is usually expressed in units of mass per unit surface (or volume) per unit time. high productivity means that there is a high generation of biomass in the ecosystem.

Question 21

character displacement

Answer 21

the phenomenon where differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species’ distributions do not overlap.

Question 22

niche

Answer 22

the particular set of habitat requirements of a certain species and the role that species has in its ecosystem

Question 23

mimicry

Answer 23

a phenomenon in which one species has evolved to look or sound like another species

Question 24

facilitation

Answer 24

early arriving species make the conditions more favorable for later species

Question 25

competitive exclusion principle

Answer 25

two species cannot coexist in the same ecological niche

Question 26

mullerian mimicry

Answer 26

type of mimicry where two harmful species mimic each other

Question 27

tolerance

Answer 27

early arriving species do not affect the conditions for later species

Question 28

batesian mimicry

Answer 28

type of mimicry where one harmless species mimics a harmful one

Question 29

inhibition

Answer 29

early living species negatively affect the conditions for later species

Question 30

asymmetric competition

Answer 30

one species suffers a greater fitness decline than the other

Question 31

inducible defenses

Answer 31

defenses that appear only in the presence of a predator

Question 32

symmetric competition

Answer 32

both species in competition suffer the same amount of fitness decline

Question 33

meta analysis

Answer 33

a compilation of several previous studies

Question 34

species richness

Answer 34

number of species present in an ecological community

Question 35

fundamental niche

Answer 35

space that a species occupies in the absence of a competitor

Question 36

top down control hypothesis

Answer 36

population size is limited by predators or herbivores

Question 37

species diversity

Answer 37

variety and relative abundance of species present in an community

Question 38

realized niche

Answer 38

niche species occupies in the presence of a competitor

Question 39

climax community

Answer 39

the stable final community that develops from ecological succession

Question 40

intermediate disturbance

Answer 40

moderate ecological disturbance is associated with higher species diversity than either low or high disturbance

Question 41

herbivory

Answer 41

practice of eating plants

Question 42

energy hypothesis

Answer 42

high temperatures increase species diversity by increasing productivity and the likelihood that organisms can tolerate the physical conditions in a region

Question 43

keystone species

Answer 43

species that has a greater impact on its ecosystem than its numbers would indicate

Question 44

disturbance

Answer 44

any event that disrupts a community, usually causing loss of some individuals or biomass

Question 45

shannon index

Answer 45

used to characterize diversity within a species