chapter 37: populations

Question 1

Ecology

Answer 1

the study of the relationships among organisms and the environment

Question 2

population

Answer 2

consists of interbreeding organisms of one species occupying the same area at the same time

Question 3

community

Answer 3

includes all populations, representing multiple species, in the same region

Question 4

ecosystem

Answer 4

the biotic community plus the abiotic environment

Question 5

biotic

Answer 5

living

Question 6

abiotic

Answer 6

nonliving

Question 7

biosphere

Answer 7

all parts of the planet where life exists

Question 8

habitat

Answer 8

the physical location where the members of a population live

Question 9

population density

Answer 9

the number of individuals of a species per unit area of unit volume of a habitat

Question 10

population distribution

Answer 10

describes how individuals are scattered through the habitat

Question 11

the three types of population distribution

Answer 11

uniform, clumped, and random

Question 12

three ways of estimating population size

Answer 12

aerial photos, sampling small subset, and mark-recapture

Question 13

The separated populations are local [blank]. If separated for a long period of time, they may become [blank]

Answer 13

subpopulations

new species

Question 14

what factors affect population size

Answer 14

births, deaths, immigration, and emigration

Question 15

birth rate

Answer 15

the number of individuals produced per unit of time

Question 16

immigration

Answer 16

the movement of individuals into a population

Question 17

death rate

Answer 17

the number of deaths per unit of time

Question 18

emigration

Answer 18

the movement of individuals out of a population

Question 19

age structure

Answer 19

helps determine whether a population is growing, stable, or declining

Question 20

survivorship curves

Answer 20

shows the proportion of surviving individuals at each age

Question 21

It is especially useful to determine what percentage of individuals survive to reproductive age, since…

Answer 21

only they will contribute to the size of the next generation

Question 22

life tables

Answer 22

follow a group of individuals within a population from birth to death

Question 23

the three types of survivorship curves

Answer 23

type I, type II, and type III

Question 24

the type of survivorship curve that includes humans and other large vertebrates

Answer 24

type I

Question 25

the type of survivorship curve that includes many birds and mammals

Answer 25

type II

Question 26

the type of survivorship curve that includes many fishes, most invertebrates, and plants

Answer 26

type III

Question 27

type I (late loss)

Answer 27

representative of species that invest much energy caring for young and have low death rates early in life. Most individuals survive to reproduce

Question 28

type II (constant loss)

Answer 28

species have approximately equal probability of dying at any age

Question 29

type III (early loss)

Answer 29

representative of species that invest little energy raising their young and have high death rates among offspring. Few individuals survive to reproductive age

Question 30

population growth is calculated using this equation

Answer 30

G = rN

Question 31

what do the letters in the population growth equation stand for?

Answer 31

``` G = the growth rate r = the per capita rate of increase N = the initial size of the population ```

Question 32

since r is [blank], G increases as N [blank]

Answer 32

constant | increases

Question 33

a population is growing exponentially when...

Answer 33

its growth rate increases over a given time period

Question 34

Exponential growth curves are [blank] shaped

Answer 34

J

Question 35

A population is growing [blank] if the number of new individuals is proportional to the size of the population

Answer 35

exponentially

Question 36

can exponential growth continue indefinitely?

Answer 36

no

Question 37

population growth levels off when

Answer 37

resources become limited or when any factor happens that increases death rate or reduces birth rate

Question 38

environmental resistance

Answer 38

the combination of factors that keeps a population from reaching its maximum growth rate

Question 39

Environmental resistance tends to increase as [blank] size increases due to...

Answer 39

population | competition, predation, and anything else that reduces birth rates or increases death rates

Question 40

carrying capacity

Answer 40

the maximum number of individuals that the ecosystem can support indefinitely

Question 41

as the population size approaches carrying capacity, the growth rate [blank].

Answer 41

slows

Question 42

populations approaching carrying capacity follows a [blank] growth model

Answer 42

logistic or s-shaped

Question 43

logistic growth equation

Answer 43

G = rN (K - N/ K)

Question 44

what does K represent in the logistic growth equation?

Answer 44

the carrying capacity

Question 45

As the population size gets close to the carrying carrying capacity, the growth rate approaches [blank]

Answer 45

zero

Question 46

do factors limiting a population size depend of the density of the population?

Answer 46

yes and no

Question 47

the effects of density-dependent factors increase as the population density [blank]

Answer 47

rises

Question 48

density-independent factors

Answer 48

exert effects that are unrelated to population density