definitions test 2

Question 1

an introduced organism that negatively alters its new environment

Answer 1

invasive species

Question 2

the presence of two or more species living in the same area

Answer 2

sympatry

Question 3

a group of species that exploit the same class of environmental resources in a similar way

Answer 3

guild

Question 4

a commonly mutualistic and intimate association between the roots of a plant and a fungus

Answer 4

mycorrhiza

Question 5

scientific name of a phylum of small marine shellfish, sometimes called “lamp shells”

Answer 5

brachiopods

Question 6

the largest ecological niche that an organism or species can occupy in the absence of interspecific competition and predation

Answer 6

fundamental niche

Question 7

the tendency for coexisting species to
differ in their niche requirements

Answer 7

niche differentiation

Question 8

the portion of its potential (fundamental) niche occupied by a species when competitors or predators are present

Answer 8

realized niche

Question 9

occurring in different places; usually refers to geographical separation of species

Answer 9

allopatry

Question 10

another word for plant-eating

Answer 10

phytophagous

Question 11

the measurable physical difference between two species that has arisen by natural selection as a result of the selection pressures on one or both from competition with the other

Answer 11

character displacement

Question 12

birds that feed on insects

Answer 12

insectivorous

Question 13

Russian scientist who described the “competitive exclusion principle”

Answer 13

Georgy Gause

Question 14

the range, for all important environmental features, within which individuals of a species can survive, grow, and reproduce

Answer 14

niche

Question 15

the distribution of organisms in which individuals are closer together than they would be if they were randomly or evenly distributed

Answer 15

aggregated distribution

Question 16

an individual liable to be, or actually, consumed (and hence killed) by a predator

Answer 16

prey

Question 17

a population perceived to exist as a series of subpopulations, linked by migration between them

Answer 17

metapopulation

Question 18

a consumer which attacks large numbers of large prey during its lifetime, but removes only a part of each prey individual, so that the effect, although often harmful, is rarely lethal in the short term, and never predictably lethal

Answer 18

grazer

Question 19

the tendency for the death rate in a population to increase, or the birth or growth rate to decrease, as the population size increases

Answer 19

density dependence

Question 20

an organism which is parasitized by a parasite

Answer 20

host

Question 21

the average number of new infected hosts that would arise from a single infectious host in a population of susceptible hosts

Answer 21

basic reproductive number (R0)

Question 22

an evolutionary theory that predicts the details of feeding behavior based on mathematical models

Answer 22

optimal foraging theory

Question 23

insects in which the adults are free-living but eggs are laid in, on or near an insect host, after which the larva develops in the host (itself usually a pre-adult), initially doing little apparent harm, but eventually consuming and killing the host before or during the pupal stage

Answer 23

parasitoids

Question 24

an organisms that consumes other organisms

Answer 24

predator

Question 25

a microorganism or virus that causes disease

Answer 25

pathogen

Question 26

an organism that obtains its nutrients from one or a very few host individuals, causing harm but not causing death immediately

Answer 26

parasite

Question 27

interference amongst predators leading to a reduction in the consumption rate of individual predators which increases with predator density

Answer 27

mutual interference

Question 28

the population size that needs to be exceeded for a parasite population to be able to sustain itself

Answer 28

threshold population size

Question 29

a classic example of predator-prey oscillations is the relationship between the snowshoe hare and the ____

Answer 29

lynx

Question 30

a consumer that invariably kills their prey, and consumes many prey items over the course of their life time

Answer 30

true predator

Question 31

when selective predation favours the coexistence of prey species that might otherwise exclude one another

Answer 31

predator mediated coexistence

Question 32

defense mechanisms that are always present in plants (eg. cell walls, waxy cuticle, bark, thorns)

Answer 32

constitutive defense

Question 33

the defenses that are produced when a plant is injured or detects foreign pathogen (eg. toxic chemicals, pathogen degrading enzymes, deliberate cell suicide)

Answer 33

inducible defenses

Question 34

a model frequently used to describe the dynamics of ecological systems in which two species interact, one a predator and one its prey

Answer 34

Lotka-Volterra Model

Question 35

small sap-sucking insects that are "farmed" by ants

Answer 35

aphids

Question 36

a close association between the individuals of pairs of species

Answer 36

symbiosis

Question 37

any agent (living or otherwise) that acts as a carrier for a pathogenic organism and transmits it to a susceptible host

Answer 37

vector

Question 38

a virus that attacks bacteria

Answer 38

phage

Question 39

an interaction between the individuals of two (or more) species in which the growth, growth rate, and/or population size of both are increased in a reciprocal association

Answer 39

mutualism

Question 40

random changes in gene frequency within a population resulting from sampling effects rather than natural selection, and hence of greatest importance in small populations

Answer 40

genetic drift

Question 41

a group of bacteria that fix nitrogen in the root nodules of most leguminous plants

Answer 41

rhizobia

Question 42

the small circular chromosome found inside mitochondria

Answer 42

mitochondrial DNA

Question 43

a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor

Answer 43

clade

Question 44

plant-defensive substances that can kill in small doses and tend to be induced by herbivore attacks

Answer 44

qualitative chemicals

Question 45

mycorrhiza that penetrate within the roots of the host

Answer 45

arbuscular mycorrhiza

Question 46

the process in which atmospheric nitrogen is converted into ammonia

Answer 46

nitrogen fixation

Question 47

the existence within a species or population of different forms of individuals or "morphs"

Answer 47

polymorphism

Question 48

the tendency of animals to return very close to their place of birth to breed

Answer 48

natal philopatry

Question 49

plant-defensive substances that are digestion-reducing, rely on an accumulation of ill effects, and tend to be produced all the time

Answer 49

quantitative chemicals

Question 50

The process by which members of two (or more) species contribute reciprocally to the forces of natural selection that they exert on each other

Answer 50

coevolution

Question 51

differences in DNA that are favored in different individuals / the genetic diversity within a species that enables it to adapt to changing environmental conditions

Answer 51

adaptive variation

Question 52

differences in DNA that do not affect fitness of the individuals

Answer 52

neutral variation

Question 53

a technique to make many copies of a specific DNA region in vitro

Answer 53

polymerase chain reaction (PCR)

Question 54

regions of DNA where the same small number of bases is repeated many times

Answer 54

microsatellites

Question 55

determining the order of the four chemical building blocks - called "bases" - that make up the DNA molecule

Answer 55

sequencing

Question 56

a genomic variant at a single base position in the DNA

Answer 56

single nucleotide polymorphism (SNPs)

Question 57

the process in which the animal ingests part of its feces in order to increase nutrient uptake

Answer 57

refection (/pseudorumination/cecotrophy)

Question 58

number of species present in a community

Answer 58

species richness

Question 59

a flightless parrot form New Zealand

Answer 59

kakapo

Question 60

a community where some species are competitively superior to others so that an initial colonizer of an opening left by a disturbance cannot necessarily maintain its presence there

Answer 60

dominance-controlled community

Question 61

communities where a large number of species are approximately equivalent in their ability to colonize an opening left by a disturbance, are equally well fitted to the abiotic environment, and can hold the location until they die

Answer 61

founder-controlled community

Question 62

photosynthesizing microscopic biotic organisms that inhabit the upper sunlit layer of almost all oceans and bodies of fresh water on Earth

Answer 62

phytoplankton

Question 63

important pests of potatoes

Answer 63

colorado potato beetles

Question 64

representation of feeding relationships in a community that includes all the links revealed by dietary analysis

Answer 64

food web

Question 65

organisms that are typical of unstable or periodically extreme environments, e.g. deserts or ephemeral ponds, and characterized by a strong dispersal ability (typically smaller than equilibrium species and have shorter life cycles)

Answer 65

fugitive/pioneer/opportunist species

Question 66

occurs when the severity of disturbance is insufficient to remove all the existing vegetation and soil from a site

Answer 66

secondary succession

Question 67

collection of species that occur together in space and time

Answer 67

community

Question 68

a community that returns rapidly to something like its former structure after a disturbance

Answer 68

resilient community

Question 69

a community that undergoes relatively little change in its structure in the face of a disturbance

Answer 69

resistant community

Question 70

the presumed endpoint of a successional sequence; a community that has reached a steady state

Answer 70

climax

Question 71

a species whose removal would produce a significant effect in the community of which it is part, changing its fundamental nature

Answer 71

keystone species

Question 72

spatially separate portions of a species’ population, between which there is only limited dispersal compared to the rate of dispersal within them

Answer 72

subpopulations

Question 73

a tendency in a population for some factor to cause density to increase when it is low and to decrease when it is high

Answer 73

population regulation

Question 74

the combined effects of all the factors and processes that affect population size (whether density-dependent or not)

Answer 74

determination of abundance

Question 75

"killing power" of an environment

Answer 75

k-value

Question 76

a series of sites that differ in age and succession levels since abandonment or disturbance

Answer 76

chronosequence

Question 77

patches within which many species suffer local extinction simultaneously

Answer 77

gaps

Question 78

which occurs when a predator reduces the abundance of its prey, and this cascades down to the trophic level

Answer 78

trophic cascade

Question 79

succession in an area that has not previously been influenced by a community

Answer 79

primary succession

Question 80

the nonseasonal, directional, and continuous pattern of colonization and extinction on a site by populations

Answer 80

succession

Question 81

the amount of water that could be evaporated and transpired if there was sufficient water available (a measure of atmospheric energy)

Answer 81

potential evapotranspiration

Question 82

enrichment of water body with plant nutrients

Answer 82

eutrophication

Question 83

the diversity between two different regions, each with many communities

Answer 83

gamma diversity

Question 84

this hypothesis explains how environmental temperature may affect a community of organisms

Answer 84

energy hypothesis

Question 85

bottom-dwelling organisms in aquatic systems

Answer 85

benthic organisms

Question 86

environments that are dominated by an extreme abiotic factor such as temperature or acidity

Answer 86

harsh environments

Question 87

the study of distribution of species and community composition on islands

Answer 87

island biogeography

Question 88

the increase in species richness if you move from the Arctic to the equator

Answer 88

latitudinal gradient

Question 89

the length of the portion of resources that an organism uses

Answer 89

niche breadth

Question 90

the diversity within a community

Answer 90

alpha diversity

Question 91

large circular current in the middle of the ocean

Answer 91

gyre

Question 92

a term that refers to diversity between communities

Answer 92

beta diversity

Question 93

the general pattern of increase in species richness with increasing area of observation

Answer 93

species-area relationship

Question 94

the developers of the equilibrium theory of island biogeography

Answer 94

MacArthur and Wilson

Question 95

the theory that local species diversity is maximized when ecological disturbance is neither too rare nor too frequent

Answer 95

intermediate disturbance hypothesis

Question 96

the model to obtain a quantitative estimate of biological variability that can be used to compare biological entities in space or in time

Answer 96

Shannon-Weaver diversity index

Question 97

the theory where enrichment destabilizes predator–prey systems, causing species extinction

Answer 97

paradox of enrichment

Question 98

an area with an uneven distribution of environmental characteristics

Answer 98

spatial heterogeneity