Chapter 4 Vocabulary

Question 0

Biotic potential

Answer 0

Reproductive capacity; the potential of a species for increasing its population and/or distribution; the biotic potential of every species is such that, given optimum conditions, its population will increase

Question 1

Exponential increase

Answer 1

The growth produced when a base population increases by a given percentage (as opposed to a given amount) each year; exponential increase is characterized by doubling again and again, each doubling occurring in the same period of time; produces a j-shaped curve

Question 2

Reproductive strategies

Answer 2

R represents the slope of the line representing exponential growth, K represents the carrying capacity of a habitat for members of a given sort of organism

Question 3

Environmental resistance

Answer 3

The totality of factors such as adverse weather conditions, shortages of food or water, predators, and diseases that tend to cut back populations and keep them from growing or spreading

Question 4

Replacement level

Answer 4

(Replacement fertility) the fertility rate (level) that will just sustain a stable population

Question 5

Carry capacity

Answer 5

The maximum population of a given species that an ecosystem can support without being degraded or destroyed in the long run; the carrying capacity may be exceeded, but not without lessening the system’s ability to support life in the long term

Question 6

Density dependent

Answer 6

Attribute of population-balancing factors, such as predation, that increase and decrease in intensity in proportion to population density

Question 7

Population density

Answer 7

The number of individuals per unit of area

Question 8

Density independent

Answer 8

Both living and non-living things can influence the size of a population of organisms; some things that happen to populations such as disease and parasites depend on the size of the population to be successful at causing destruction

Question 9

Critical number

Answer 9

The minimum number of individuals of a given species that is required to maintain a healthy, viable population of the species; if a population falls below its critical number, it will almost certainly become extinct

Question 10

Endangered

Answer 10

A species whose total population is declining to relatively low levels such that, if the trend continues, the species will likely become extinct

Question 11

Top-down regulation

Answer 11

Basic control of a population (or species) occurs as a result of predation

Question 12

Bottom-up regulation

Answer 12

Basic control of a natural population occurs as a result of the scarcity of some resource

Question 13

Overgrazing

Answer 13

The phenomenon of animals’ grazing in greater numbers than the land can support in the long term

Question 14

Keystone species

Answer 14

A species whose role is essential for the survival of many other species in an ecosystem

Question 15

Territoriality

Answer 15

The behavioral characteristic exhibited by many animal species, especially birds and mammalian carnivores, to mark and defend a given territory against other members of the same species

Question 16

Natural selection

Answer 16

The evolutionary process whereby the natural factors of environmental resistance tend to eliminate those members of a population which are least well adapted to cope with their environment and thus, in effect, tend to select those best adapted for survival and reproduction

Question 17

Riparian

Answer 17

The strip of woody plants that grow along natural watercourses

Question 18

Resource partitioning

Answer 18

The outcome of competition by a group of species where natural selection favors the division of a resource in time or space by specialization of the different species

Question 19

Ecological/natural selection

Answer 19

The evolutionary process whereby the natural factors of environmental resistance tend to eliminate those members of a population which are least well adapted to cope with their environment and thus, in effect, tend to select those best adapted for survival and reproduction

Question 20

Climax ecosystem

Answer 20

The last stage in ecological succession; an ecosystem in which populations of all organisms are in balance with each other and with existing abiotic factors

Question 21

Primary succession

Answer 21

The gradual or sometimes rapid change in the species that occupy a given area, with some species invading and becoming more numerous while others decline in population and disappear

Question 22

Resilience

Answer 22

The tendency of ecosystems to recover form disturbances through a number of processes known as resilience mechanisms

Question 23

Recruitment

Answer 23

The maturation and successful entry of young into an adult breeding population