Chapter 12,13

Question 1

population rate of change caused by

Answer 1

births, deaths, immigration, emigration

Question 2

unlimited growth caused by

Answer 2

abundant resources, individuals reproducing at max. physiological capacity, low death rates

Question 3

when is rate of change easiest to approximate

Answer 3

small populations

Question 4

growth rate equation

Answer 4

(births - deaths)/ time

Question 5

growth rate calculated using

Answer 5

per capita (per person) over unit of time

Question 6

another way of saying per capita growth rate

Answer 6

how many offspring produced per individual during a time range

Question 7

intrinsic growth rate

Answer 7

highest possible per capita growth rate; ideal conditions

Question 8

what are ideal conditions

Answer 8

maximum reproductive rate (limited by physiology)
minimum deaths (old age)

Question 9

exponential growth

Answer 9

result of intrinsic growth rate/ideal conditions

Question 10

what happens to population size when r is greater than, less than, or equal to 0

Answer 10

less than 0: decreases - more deaths
greater than 0: increases - more births
equal to 0: stays constant - births = deaths

Question 11

exponential growth model

Answer 11

continuous growth in populations that reproduce year round

Question 12

exponential growth equation

Answer 12

Nt=Noe^rt

Question 13

what is everything in Nt=Noe^rt

(exponential growth)

Answer 13

Nt=pop. size at given/later time
No= initial population
e = a constant
r= per capital growth rate
t= time

Question 14

dN/dt=rN

Answer 14

change in population per unit of time - tells how fast population is changing

Question 15

why does r never change in unlimited growth, but population grows slow at first

Answer 15

population size is small at first - population increases at exponential rate - increases more each unit of time

Question 16

discrete/geometric growth

Answer 16

organisms with discrete breeding seasons

Question 17

lambda

Answer 17

ratio of population size at two specific time intervals

Question 18

lambda =

Answer 18

Nt+1/Nt

Question 19

population size when lambda is, greater than, less than, and equal to 0

Answer 19

greater than 0: increasing
less than 0: decreasing
equal to 0: constant

Question 20

Nt=No(lambda)^t

Answer 20

population at a given time

Question 21

deltaN=No(lambda^t -1)

Answer 21

change in population over a period of time

Question 22

exponential vs geometric/discrete growth

Answer 22

exponential: year round breeding, continuous rates, graph with continuous line
discrete/geometric: specific breeding seasons, choppy rates, data points on a graph

Question 23

population growth limitations in nature

Answer 23

scarce resources: food, space

bad environment conditions: natural disasters

Question 24

density independent factor

Answer 24

influence on individuals in a population not related to population density (individual survival not affected by how many other individuals there are)

Question 25

density independent factor example

Answer 25

ectotherms affected by temperature of environment (not affected by how many individuals there are)

Question 26

density dependent factors

Answer 26

influence on individuals in population related to how many other individuals there are (overcrowded)

Question 27

what is influenced by density dependent factors

Answer 27

mortality and fecundity

Question 28

negative density dependence

Answer 28

population growth decreases as population density increases (increases deaths, decreases births)

Question 29

what does negative density dependence limit

Answer 29

resources: food, space, mates

Question 30

high population density cause higher levels of what

Answer 30

stress, disease, attraction to predators

Question 31

effects of negative density dependence on individual plants

Answer 31

less resources, smaller mass, fewer seeds

Question 32

what keeps populations near carry capacity

Answer 32

negative density dependence

Question 33

logistic growth model

Answer 33

S curve: slow growth, growth speeds up, slows down, then growth becomes constant (k)

Question 34

dN/dt=rN(1-N/k)

Answer 34

logistic growth equation

Question 35

scaling factor for r

Answer 35

(1-N/K)

Question 36

population is small, what does N/K equal

Answer 36

close to 0

Question 37

population is large, what does N/K equal

Answer 37

close to 1

Question 38

when does logistic growth change from positive to negative

Answer 38

halfway to K | (K/2)

Question 39

what can cause K to change

Answer 39

environmental conditions

Question 40

positive density dependence

Answer 40

population growth rate increases as population density increases; usually small populations

Question 41

problems with low density population

Answer 41

finding mates and resources, inbreeding, unbalances sex ratios, spotting predators

Question 42

Inflection point

Answer 42

Point where growth rate is the highest it will ever be