exam 3 ppt 5

Question 1

equation for population growth

Answer 1

delta N = (b-d) + (i-e)

Question 2

delta N=

Answer 2

change in population size

Question 3

b=

Answer 3

births

Question 4

d=

Answer 4

deaths

Question 5

i=

Answer 5

movement in (immigration)

Question 6

e=

Answer 6

movement out (emigration)

Question 7

equation for per capita growth rate

Answer 7

r = (delta N/delta t) / Nknot (Nknot = initial population size)

Question 8

t=

Answer 8

time

Question 9

what is logistic growth like?

Answer 9

may start as exponential, but levels out as growth hits carrying capacity (K)

Question 10

deltaN / deltat =

Answer 10

(births - deaths)N; can also be rN (where r is the per capita rate or increase)

Question 11

what is the assumption about r regarding exponential growth?

Answer 11

r is constant over time

Question 12

what is the assumption about movement of populations regarding exponential growth?

Answer 12

no immigraton or emigration

Question 13

what is the assumption about resources regarding exponential growth?

Answer 13

resources are unlimited (which resulgs in density independent growth)

Question 14

is exponential growth density dependent or independent?

Answer 14

density independent

Question 15

definition of density independent

Answer 15

of people in population doesn’t affect how many others are able to survive

Question 16

is exponential growth realistic?

Answer 16

not really- there is always a limit to how big a population can be

Question 17

when can exponential growth be realistic?

Answer 17

1) colonization of a new habitat (no populations there before, with ample resources), 2) recovering after a disaster (no more competition and enough resources, etc)

Question 18

what happens when resources run out? (reality)

Answer 18

density dependent growth -> logistic growth

Question 19

when should a population continue to grow regarding logistic growth?

Answer 19

if a population of size N is below the carrying capacity K, then the population should continue to grow

Question 20

equation for logistic growth

Answer 20

deltaN/deltat = rN(K-N) / K ((K-N) tells how much more pop can grow before hitting c.c.)

Question 21

if a population in logistic growth is very small, what will (K-N) be like?

Answer 21

if the population is very small, this will be 1 and the growth is pretty much exponential

Question 22

if a population in logistic growth is very large, what will (K-N) be like?

Answer 22

if a population is large and reaching c.c., this will be about 0 and deltaN/deltat will also be 0

Question 23

definition of environmental resistance

Answer 23

factors that limit population growth

Question 24

factors that limit population growth (listed)

Answer 24

density dependent factors, density independent factors

Question 25

definition of density dependent factors

Answer 25

biotic (living) factors that fluctuate with population size -> leads to logistic growth

Question 26

definition of density independent factors

Answer 26

are unrelated to population size and are usually abiotic (non-living) factors

Question 27

exps of density dependent factors

Answer 27

competition for resources, disease/parasitism, predation, social behavior, toxic wastes

Question 28

what do cyclical populations mean?

Answer 28

their populations fluctuate in response to each other (one increases, the other decreases and vice versa)

Question 29

exps of density independent factors

Answer 29

natural disasters such as floods, earthquakes, fires

Question 30

when does exponential growth occur?

Answer 30

when the growth rate r is constant

Question 31

definition of carrying capacity (K)

Answer 31

the maximum number of individuals that the environment can support; this can change if the environment changes

Question 32

is logistic growth density dependent?

Answer 32

yes

Question 33

as a population approaches its c.c., its deltaN / deltat….

Answer 33

decreases (gets closer to zero)

Question 34

if the major food source of seals decline, what would occur?

Answer 34

the c.c. and seal population would both decrease

Question 35

does the carrying capacity change based on what resources are available?

Answer 35

yes

Question 36

is human population growth currently exponential or logistical?

Answer 36

exponential

Question 37

what do trends show is happening to r in the human population?

Answer 37

trends show r is decreasing (we are currently at about 7.9 billion)

Question 38

what does age structure tell you?

Answer 38

age structure of a population tells you how many individuals re in an age group

Question 39

rapid growth age structure means…

Answer 39

broad at bottom- lot of young people, few old people

Question 40

slow growth age structure means…

Answer 40

growth is more slow vs rapid

Question 41

stable growth age structure means…

Answer 41

growth is levelling off

Question 42

exps of countries with rapid growth

Answer 42

guatemala, nigeria, saudi arabia

Question 43

what is age structure stage 1?

Answer 43

rapid growth

Question 44

what is age structure stage 2?

Answer 44

slow growth

Question 45

what is age structure stage 3?

Answer 45

stable

Question 46

exps of countries with slow growth

Answer 46

united states, australia, canada

Question 47

what does zero growth mean?

Answer 47

population is not growing in size over time

Question 48

exps of countries with zero growth

Answer 48

spain, austria, greece

Question 49

what is negative growth?

Answer 49

population is decreasing in size- having less kids, more old people vs young

Question 50

exps of countries with negative growth

Answer 50

germany, bulgaria, sweden

Question 51

in what countries is highest growth occurring?

Answer 51

highest growth is occurring in less economically developed countries