Chapter 5: Ecosystems and living organisms

Question 1

adaption

Answer 1

an evolutionary modification of an individual that improves that individual’s changes of survival and reproductive success in environment

Question 2

bacteria

Answer 2

unicellular, prokaryotic microorganisms

most are decomposes, but some are autotrophs and some are parasites

Question 3

birth rate

Answer 3

the number of births per 1000 people per year

Question 4

carrying capacity (K)

Answer 4

the maximum number of individuals of a given species that a particular environment can support for an indefinite period, assuming there are no changes in the environment

Question 5

coevolution

Answer 5

the interdependent evolution of two or more species that occur as a result of their interactions over a long period

Question 6

commensalism

Answer 6

a type of symbiosis in which one organism benefits and the other is neither harmed or helped

Question 7

community

Answer 7

an association of different species living together at the same time in a defined habitat with some degree of mutual interdependence

Question 8

community stability

Answer 8

the ability of a community to withstand environmental disturbances

Question 9

community

Answer 9

an association of different species living together at the same time in a defined habitat with some degree of mutual interdependence

Question 10

community stability

Answer 10

the ability of a community to withstand environmental disturbances

Question 11

competitioni

Answer 11

the interaction among organisms that vie for the same resources in an ecosystem

Question 12

competitive exlcusion

Answer 12

the concept that no two species with identical living requirements can occupy the same ecological niche indefinitely. eventually one species will be excluded

Question 13

cryptic coloration

Answer 13

colors or markings that help certain organisms hide from predators by blending into their surroundings

Question 14

death rate

Answer 14

the number of deaths per 1000 people per year

Question 15

density-dependent factor

Answer 15

an environmental factor whose effects on a population changes as population density changes

Question 16

density-independent factors

Answer 16

an environmental factor that effects the size of a population but is not influenced by changes in population density

Question 17

dispersal

Answer 17

the movement of individuals among populations, from one region or country to another

Question 18

ecological niche

Answer 18

the totality of an organism’s adaptations, its use of resources, and the lifestyle to which it is fitted

Question 19

ecological successions

Answer 19

the sequence of changes in a plant community over time

Question 20

ecosystems

Answer 20

the interacting system that encompasses a community and its nonliving physical environment

Question 21

ecosystems services

Answer 21

important environmental benefits that ecosystems provide to people; include clean air to breathe, clean water to drink, and fertile soil in which to grow crops

Question 22

ecotone

Answer 22

the transitional zone where to ecosystems or biomes integrate

Question 23

emigration

Answer 23

a type of dispersal in which individuals leave a population and thus decrease its size

Question 24

environmental resistance

Answer 24

Limits set by the environment that prevent organisms from reproducing indefinitely at their intrinsic rate of increase; includes the limited availability of food, water, shelter, and other essential resources, as well as limits imposed by disease and predation.

Question 25

evolution

Answer 25

Cumulative genetic changes that occur over time in a population of organisms; it explains many patterns of distribution and abundance displayed in the natural world

Question 26

exponential population growth

Answer 26

the accelerating population growth that occurs when optimal conditions allow a constant reproductive rate over a period of time

Question 27

fundamental niche

Answer 27

no competition or other species, ideal

Question 28

growth rate

Answer 28

the rate of change of population's size expressed in percent per year

Question 29

habitat

Answer 29

the local environment in which an organism, population, or species lives

Question 30

immigration

Answer 30

a type of dispersal in which individuals enter a population and thus increase its size

Question 31

intrerspecific competition

Answer 31

competition between members of different species

Question 32

intrinsic rate of increase

Answer 32

the exponential growth of a population that occurs under ideal conditions

Question 33

keystone species

Answer 33

us

Question 34

limiting resource

Answer 34

any environmental resource that, because it is scarce or at unfavorable levels, restricts the ecological niche of an organism

Question 35

metapopulation

Answer 35

a set of local populations among which individuals are distributed in district habitat patches across a landscape

Question 36

mutation

Answer 36

a change in the DNA of an organism

Question 37

mutulaism

Answer 37

a symbiotic relationship in which both partners benefit

Question 38

natural selection

Answer 38

the process in which better-adapted individuals are more likely to survive and reproduce increasing their proportion in the population

Question 39

parasitism

Answer 39

a symbiotic relationship in which one organism benefits and the other is adversely affected

Question 40

pathogen

Answer 40

an agent that causes disease

Question 41

population

Answer 41

a group of individuals of the same species that live in the same geographic are at the same time

Question 42

population density

Answer 42

the number of individuals of a species per unit or area or volume at a given time

Question 43

population ecology

Answer 43

the branch of biology that deals with the numbers of a particular species that are found in an area and how and why those numbers change over time

Question 44

predation

Answer 44

the consumption of one species by another

Question 45

primary succession

Answer 45

the change in species composition over time in a previously uninhabited environment

Question 46

realized niche

Answer 46

actual organism's environment

Question 47

resource partioning

Answer 47

the reduction in competition for environmental resources that occurs among coexisting species as a result of each species' niche differing from those of the others in one or more ways

Question 48

secondary succession

Answer 48

the change in species composition that takes place after some disturbance destroys the existing vegetation; soil is already present

Question 49

species richness

Answer 49

the number of species in a community

Question 50

succession

Answer 50

the sequence of changes in a plant community over time

Question 51

survivorhsip

Answer 51

the probability a given individual in a population will survive to a particular age

Question 52

symbionts

Answer 52

the partners of a symbiotic relationship

Question 53

symbiosis

Answer 53

any intimate relationship or association between members of two or more species; includes mutualism, commensalism, and parasitism

Question 54

zooxanthellae

Answer 54

algae that live inside coral animals and have a mutualistic relationship with them