chapter 6

Question 1

population

Answer 1

the individuals that belong to the same species and live in a given area at a particular time

Question 2

community

Answer 2

all of the populations of organisms within a given area

Question 3

population ecology

Answer 3

the study of factors that cause populations to increase or decrease

Question 4

population size

Answer 4

the total number of individuals within a defined area at a given time

Question 5

population density

Answer 5

the number of individuals per unit area at a given time

Question 6

population distribution

Answer 6

a description of how individuals are distributed with respect to one another

Question 7

sex ratio

Answer 7

the ratio of males to females in a population

Question 8

age structure

Answer 8

a description of how many individuals fit into particular age categories in a population

Question 9

limiting resource

Answer 9

a resource that a population cannot live without and that occurs in quantities lower than the population would require to increase in size

Question 10

density dependent factor

Answer 10

a factor that influences an individuals probability of survival and reproduction in a manner that depends on the size of the population

Question 11

carrying capacity

Answer 11

the limit of how many individuals in a population the environment can sustain

Question 12

density independent factor

Answer 12

a factor that has the same effect on an individuals probability of survival and the amount of reproduction at any population size

Question 13

population growth rate

Answer 13

the number of offspring an individual can produce in a given time period minus the deaths of the individual or its offspring during the same period

Question 14

intrinsic growth rate

Answer 14

the max potential for growth of a population under ideal conditions with unlimited resources

Question 15

exponential growth model

Answer 15

growth model estimating the size of a population in the future

Question 16

j shaped curve

Answer 16

the curve of the exponential growth model when graphed

Question 17

logistic growth model

Answer 17

growth that is intially exponential but slows as population reaches carrying capacity

Question 18

s shaped curve

Answer 18

the shape of the logistic graph

Question 19

overshoot

Answer 19

when a population becomes larger than the carryin capacity

Question 20

die off

Answer 20

rapid decline in population due to death

Question 21

k selected species

Answer 21

a species with low intrinsic growth rate that causes the population to increase slowly until it reached carrying capacity

Question 22

r related species

Answer 22

a species that has a high intrinsic growth rate which often leads to population overshoots and die offs

Question 23

survivorship curve

Answer 23

a graph that represents the distinct patterns of species survival as a function of age

Question 24

type 1 survivorship curve

Answer 24

a pattern of survival over time in which there is high survival throughout most of the life span but then individuals die in large numbers as they reach old age

Question 25

type 2 survivorship curve

Answer 25

a pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span

Question 26

type 3 survivorship curve

Answer 26

a pattern of survival over time in which there is low survivorship early in life with few individuals reaching adulthood

Question 27

corridor

Answer 27

strips of natural habitat that connect populations

Question 28

metapopulation

Answer 28

a group of spatially distinct populations that are connected by occasional movements of individuals between them

Question 29

inbreeding depression

Answer 29

when individuals with similar genotypes breed with each other and produce offspring that have an impaired ability to survive and reproduce

Question 30

community ecology

Answer 30

the study of interactions between species

Question 31

symbiotic relationship

Answer 31

the relationship between two species that live in close association with each other

Question 32

competition

Answer 32

the struggle of individuals to obtain a shared limited resource

Question 33

competitive exclusion principle

Answer 33

the principle stating that two species competing for the same limiting resource cannot coexist

Question 34

resource partitioning

Answer 34

when two species divide a resource based on differences in their behavior or morphology

Question 35

predation

Answer 35

one animal kills another

Question 36

parasitoid

Answer 36

predator that lays eggs inside another organism

Question 37

parasitism

Answer 37

an interaction in which one organism lives on or in another organism

Question 38

pathogen

Answer 38

a parasite that causes disease in its host

Question 39

herbivory

Answer 39

an interaction in which an animal consumes a producer

Question 40

mutualism

Answer 40

an interaction between two species that increases the chances of survival or reproduction for both species

Question 41

commensalism

Answer 41

one species benefits the other doesnt care

Question 42

keystone species

Answer 42

species that plays a far more important role in its community than its relative abundance might suggest

Question 43

ecosystem engineer

Answer 43

a keystone species that created or maintains habitat for other species

Question 44

ecological succession

Answer 44

the predictable replacement of one group of species by another species over time

Question 45

primary succession

Answer 45

ecological succession occuring on surfaces that are initially devoid of soil

Question 46

secondary succession

Answer 46

succession of plant life that occurs in areas that have been distributed but no lost their soil

Question 47

pioneer species

Answer 47

a species that can colonize new areas rapidly and grow well in full sunshine

Question 48

theory of island biogeography

Answer 48

a theory that demonstrates the dual importance of habitat size and distance in determining species richness