Chapter 20

Question 1

Most Common pattern of distribution

Answer 1

clumped

Question 2

Least common pattern of distribution

Answer 2

random

Question 3

Factors affecting population growth

Answer 3

birth rate
death rate
immigration
emigration

Question 4

population explosion

Answer 4

rapid increase in population that’s too fast to be contained

Question 5

population crash

Answer 5

rapid decrease in population

Question 6

Biotic Potential

Answer 6

the highest possible per capita growth rate

Question 7

Lag phase

Answer 7

slow population growth due to few individuals able to reproduce

Question 8

Exponential growth phase

Answer 8

(r)

rapid population growth due to much higher birth rate then death rate

Question 9

Stationary Phase

Answer 9

birth and death rates are equal

Question 10

Carrying Capacity

Answer 10

(k)

theoretical maximum sustainable population

Question 11

Density Dependent Factors

Answer 11

biotic factors that limit the carrying capacity

predators, parasites, disease

Question 12

Density Independent Factors

Answer 12

abiotic factors that limit carrying capacity

droughts, floods, fires

Question 13

Environmental Resistance

Answer 13

total affect of all limiting factors (biotic and abiotic)

Question 14

r Selected Strategies

Answer 14

species that produce close to their biotic potential

short life span
many offspring
affected by density independent factors

exp mouse

Question 15

k Selected Strategies

Answer 15

populations which live close to their carrying capacity

larger
less offspring
affected by density dependent factors

elephant

Question 16

Open populations

Answer 16

changes through immigration and emigration and birth/death rates

Question 17

Closed populations

Answer 17

only change through birth and death rates not immigration and emigration

Question 18

community

Answer 18

interacting populations within a given area

Question 19

Intraspecific competition

Answer 19

competition within a species for resources

affected by density dependent factors

Question 20

Interspecific competition

Answer 20

competition btw species for resources

includes invasive species

Question 21

Competitive exclusions principle

Answer 21

no two species can occupy the same niche n a community

Question 22

Defences Against Consumers

Answer 22

poor taste like poison
physical protection like thorns
protective camouflage

Question 23

Batesian Mimicry

Answer 23

harmless animals evolve to look like harmful ones

Question 24

Mullerian Mimicry

Answer 24

2 harmfully animals evolve to look like each other

Question 25

Symbiosis

Answer 25

relationship between two species

Question 26

mutualism

Answer 26

both species benefit

Question 27

commensalism

Answer 27

one benefits and the other isn’t harmed

Question 28

parasitism

Answer 28

one benefits and the host is harmed

Question 29

succesion

Answer 29

change in an ecosystem over time

driven by abiotic and biotic factors

Question 30

Primary Succession

Answer 30

begins where no soil is present to begin with, takes a long time

pioneer community are the first organisms to populate this area

climax community: the stable community the eventually developed

Question 31

Secondary Succession

Answer 31

begins when soil is present but the old community has been destroyed, occurs faster the primary succession

includes pioneer species and the climax community

Question 32

Age pyramids

Answer 32

triangle: rapid population growth
rectangle: stable population
inverted triangle: decreasing population