Topic 11 Population growth lecture notes

Question 1

change in total numbers of individuals in a population formula (2)

Answer 1

Delta N/Deta T

birth rate-death rate

Question 2

Per capita birth rate (b)

Answer 2

b=B/N

B=number of births

N=population number

Question 2

Per capita birth rate (b)

Answer 2

b=B/N

B=number of births

N=population number

Question 3

Per capital death rate (d)

Answer 3

d=D/N
# of death/Population Number

Question 4

per capital growth rate (r)

Answer 4

b-d

birth rate-death rate

Question 5

What does it mean when r is +,0 and -?

Answer 5

r=0
population is no change

r=+ growing population

r=- declining population

Question 6

rmax

Answer 6

intrinsic rate of increase

idealized value when there is no external pressure operating on it

Question 7

rmax is related to

Answer 7

generation time, time to sexual maturity

not really to size because cicadas, are small buy they have a 17 year generation time.

Question 8

rmax and gen time

Answer 8

longer generation time= lower rmax

Question 9

formula for determining the size of a population growing exponentially

Answer 9

Nt=N0(1+rmax)^t

Question 10

N and R relationship

Answer 10

as population size (N) gets bigger, growth rate is decreasing.

Question 11

What limits population growth? (6)

Answer 11

1. predators
2. limited food
3. limited shelter
4. temperature
5. precipitation
6. disease

Question 12

How close the population size is to the carrying capacity changes____

Answer 12

r

Question 13

the three scenarios with N, K and r

Answer 13

1. when N=K r=0
2. when N<K.>0</K.>
3. when N>K, r<0

Question 14

growth rate (rt) formula (Logistic model) + verbal explanations

Answer 14

rt=rmax ((K-Nt)/K)
innate capacity for increase X Unutilized opportunity for growth

Question 15

population size growing logistically formula

Answer 15

Nt+1=N(1+rt)

Question 16

you have to calculate growth rate every year

Answer 16

bc the difference between the population size and carrying capacity

Question 17

density dependent factors (6)

Answer 17

biotic
food avaliability
shelter
mates
predation
disease

Question 18

Density Independent factors (6)

Answer 18

abiotic
temp
precipitation
disturbance (fires, floods)

Question 19

Exponential model

Answer 19

When populations experience unlimited growth

Question 20

Logistic Models

Answer 20

populations growth is limited bc resources are finite

Question 21

Tracking changes in number of individuals in a population involve monitoring 4 types of demographic change

Answer 21

1. number of births
2. number of deaths
3. number of immigrants
4. Number of emigrants

Question 22

the intrinsic rate of increase is high for_____ and low for those

Answer 22

protists and animals with short generation time and low for those with long generation rime

Question 23

generation time

Answer 23

the average interval between the birth of an individual and the birth of its offspring.

Question 24

K according to textbook is

Answer 24

a property of the environment that can vary from one habitat to another

Question 25

Logistic model (3)

Answer 25

• r decrease as the population gets larger
• r decrease linearly as population size increase

-population growth slows as population size approaches K

Question 26

K-N/K

Answer 26

What proportion of the carrying capacity still available

Question 27

What does Crowding do?

Answer 27

1. Decrease individual growth rate,
2. decrease adult size
3. decrease survival of plants and animals

Question 28

Individuals living in very dense populations are (4)

Answer 28

unable to harvest enough resources, grow slowly and tend to be small weak and less likely to survive.

Question 29

females in crowded populations (2)

Answer 29

produce either fewer offsprings or smaller offsprings that are less likely to survive.

**less energy for reproduction after meeting its basic needs for maintenance

Question 30

population density and population size relationship

Answer 30

increase in population density causes population size to decrease. Decrease in density cause it to increase

Question 31

How does predation cause density dependent population regulation

Answer 31

as a particular prey species becomes more numerous, predators may consume more of it because it is easier to find and catch. Once a prey species exceeds some threshold density, predators may consume a larger percent of its population amounting to a density dependent effect

Question 32

Density-dependent factors with K relationship

Answer 32

are limiting factors that contribute to determining carrying capacity while depending on the density of the population. That is, density-dependent factors tend to be more strongly effective at regulating population growth once a population reaches a certain range or level.

Question 33

Density-independent factors and K relationship

Answer 33

are limiting factors that do not regulate population growth for populations reaching certain levels. These factors tend to be abiotic (nonliving) such as unusual weather, cataclysms, natural disasters, and pollution; all of which can affect birth and death rates but without being determined by a population’s current range.

Question 34

The success of r selected depends on

Answer 34

flooding the the environment with a large quantity of young because only some may be successful.

Question 35

r selected can be reduced by___ so they may never

Answer 35

changes in abiotic environmental factors so that they may never grow large enough to reach K and face a shortage of limiting resources

Question 36

Most K selected species have

Answer 36

low rmax meaning their population often grow slowly

Question 37

the success of K selected species depends on

Answer 37

the production of a relatively small number of high quality offspring that join an already well established population