Unit 3

Question 1

jCompetitive Exclusion Principle

Answer 1

postulates that 2 species which compete for the same limited resource cannot coexist at constant population values

Question 2

Niche Differentiation

Answer 2

refers to the process by which competing species use the environment differently in a way that helps them to coexist

Question 3

Resource partitioning

Answer 3

the phenomenon where 2 or more species divide out resources like food, space, etc to coexist

Question 4

Example of resource partitioning:

Answer 4

warblers can coexist because they live in different parts of trees

Question 5

Predator partitioning:

Answer 5

-occurs when species are attacked by different predators
-if each species is constrained by different natural enemies, they will be able to coexist

Question 6

Conditional Differentiation

Answer 6

occurs when species differ in their competitive abilities based on varying environmental conditions

Question 7

Example of Conditional Differentiation:

Answer 7

Some plants in the desert thrive during wet years, while others thrive during the dry years

Question 8

Coexistence Theory:

Answer 8

a framework to understand how competitor traits can
- maintain species diversity
- stave off competitive exclusion

Question 9

Equalizing mechanisms:

Answer 9

-reduce fitness differences b/w species
-merges the competitive abilities of multiple species closer together
-any species with the lowest R* is the best competitor

Question 10

Stabilizing mechanisms:

Answer 10

-encourages an individual to compete more with its own species
-multiple species can coexist if they are in a changing environment; each species must have a unique response to this

Question 11

Character displacement:

Answer 11

the idea that differences among similar species whose distributions overlap geographically are ACCENTUATED in regions where species co-occur but are MINIMIZED when there is no overlap

Question 12

Example of character displacement:

Answer 12

Different beak sizes of finches allow them to coexist in the same region

Question 13

Example of equalizing mechanisms:

Answer 13

An abundance of lantern flies last year because birds did not know they were food because they’re brightly colored (usually a symbol of toxicity)
-a lot less this year because their color is associated with food now

Question 14

Food chain:

Answer 14

a linear sequence of organisms through which nutrients and energy pass

Question 15

3 Components of a food web:

Answer 15

1. Producers (autotrophs)
2. Consumers(heterotrophs)
3. Decomposers(Detritvores)

Question 16

Producers:

Answer 16

plants or algae

Question 17

Consumers

Answer 17

species that cannot manufacture their own food and need to consume others

Question 18

Decomposers:

Answer 18

break down dead plant and animal material and wastes and release it again as energy and nutrients into the ecosystem

Question 19

Ecosystem:

Answer 19

communities of organisms interacting with an abiotic environment

Question 20

Net primary productivity:

Answer 20

the rate at which energy is stored as biomass or other primary producers made available to the consumers in the ecosystem

Question 21

True or False: Mutualism can aid in defense against enemies?

Answer 21

True

Question 22

True or False: Mutualism has no effect on species diversity?

Answer 22

False `

Question 23

Interspecific competition:

Answer 23

occurs when two or more species must share a limited resource

Question 24

Exploitation Competition:

Answer 24

populations depress one another through the use of a shared resource

Question 25

Inference Competition:

Answer 25

individuals or populations behave in a way that decreases the exploitation efficiency of another individual or population

Question 26

Apparent competition:

Answer 26

when 2 unrelated prey species indirectly compete for survival through a shared predator `

Question 27

R* Theory:

Answer 27

predicts that the availability of the most limiting resource controls population growth

Question 28

Species evenness:

Answer 28

compares the relative abundance or each species in the community

Question 29

Rank-abundance curves:

Answer 29

indicate how communities differ in species richness and evenness

Question 30

Keystone species

Answer 30

substantially affect community structure despite being few in number

Question 31

What can keystone species act as?

Answer 31

ecosystem engineers because they control species diversity by manipulating the habitat

Question 32

What is secondary productivity?

Answer 32

when chemical energy from producers (trees) is converted to chemical bonds in consumers(animals)

Question 33

Does beef or eggs take more energy to produce?

Answer 33

beef

Question 34

What are the 2 main food chains in ANY ecosystem?

Answer 34

-grazing food chain
-detrital food chain

Question 35

Grazing food chain

Answer 35

based on living plant biomass

Question 36

Detrital food chain

Answer 36

based on non-living organic matter

Question 37

10% law

Answer 37

transfer of energy from one trophic level to the next

Question 38

4 trophic levels:

Answer 38

-primary producer
-primary consumer
-secondary consumer
-tertiary consumer