Exam 3

Question 1

If a predator must actively search for a prey, then what should be expected?
*E/(h+s)

Answer 1

energy gained should offset that used in searching & handling prey

Question 2

what is a mechanical defense plants use againts mammal herbavores?

Answer 2

spines

Question 3

What did ecologist Christen Raunkiaer observed in his studies?

Answer 3

that species abundances seem to have a regular distribution (inverted J)

Question 4

the ratio between what determines the proportion of occupied patches at metapopulation equilibrium?

Answer 4

extinction & colonization

Question 5

what does Leibig’s law of minimum states?

Answer 5

that there is one single limiting resource to population growth

Question 6

what is taken into account for Lotka-Volterra-Gause competition model?

Answer 6

the carrying capacity of both competitors

Question 7

how does digestive rate model differs from optimal foraging theory?

Answer 7

it focuses on digestion rate rather than ingestion rate

Question 8

how to calculate lx or Ro?

Answer 8

• # alive divided by # alive initially

- Ro = sum of (lx. bx)

Question 9

list the assumption of the Lotka-Volterra predator-prey model

Answer 9

• exponential growth of prey population
• removal of prey by predators only
• predator declines when starving

Question 10

what applies to open communities?

Answer 10

chance association of organisms that are adapted to live in the same area

Question 11

why do plankton population densities fluncuates more than sheep’s?

Answer 11

• they have a shorter life span & a higher turnover
• have higher intrincis mortality rate
• have higher reproductive rate

Question 12

how is per capita birth rate calculated as?

Answer 12

total # of births over total # of individuals

Question 13

What can be said about p. aurelia & p. caudalum?

Answer 13

p. aurelia is the stronger competitor

Question 14

what does the sit-&-wait foraging mode depend on?

Answer 14

• high density of prey
• high prey mobility
• low predator energy requirements

Question 15

if a mutant coffee plant has 15 times less caffeine than wild-type seeds, what can happen to it?

Answer 15

it’s pod would probably be more damaged by seed predators

Question 16

What happened in georgii’s experiment?

Answer 16

in part 1, all preys was comsumed resulting in extinction of predators. in part 2, preys can now hide & recover, no extinction

Question 17

what happens when rarefraction curves does not perfectly plateau?

Answer 17

some rare species may be missing

Question 18

what is the most logical way to scale down a study with limited funding of DeVries’s butterfly diversity?

Answer 18

run the study with the same method for fewer years

Question 19

what is the association between mycorrhizal fungi & land plants an example of?

Answer 19

trophic mutualism

Question 20

the evolution of mutualistic interactions implies an increase in what?

Answer 20

fitness of both partners

Question 21

define species abundance

Answer 21

the # of individuals of each species present in a given community

Question 22

what is observed in Lotka-Volterra predator-prey model of snowshoe hare & lynx?

Answer 22

lynx cycles follow hare cycles & abundance peaks are slightly offset

Question 23

in plant defence what does induced production of chemicals after damage suggest?

Answer 23

that defence has a cost

Question 24

list Density-dependent factors that regulate population growth

Answer 24

• space
• norishment
• predators
• parasites
• diseases

Question 25

what conclusion could be said about Robert Whittaker’s gradient analyses

Answer 25

despite differences in abundance, several plants appear across moisture gradient

Question 26

what is the association between honey bee & flowering plants an example of?

Answer 26

mutualism

Question 27

why is there a different value for carrying capacity for each subpopulation of spotted owls constituting a metapopulation?

Answer 27

because patches of suitable owl habitats vary in size

Question 28

what is the phenomenon where perturbations at one level of trophic web spread across all other levels called?

Answer 28

trophic cascade

Question 29

declare a statement that constitutes an aspect of metapopulation dynamics that is highly relevant to conservation biology

Answer 29

metapopulation is maintained even if some subpopulations go extinct

Question 30

list Density-independent factors that regulate population growth

Answer 30

• temperature
• humidity
• catastrophic events

Question 31

define species richness

Answer 31

the # of species present in a given community

Question 32

what does the competitive exclusion principle state?

Answer 32

that 2 species with identical niches cannot coexist

Question 33

what is exemplified when a tertiary consumer is introduced?

Answer 33

top-down control, given that relative biomass alternates between trophic levels

Question 34

34) in a graph with 4 fluncuating lines, what does it show?

Answer 34

population cycles that vary independently for 4 different species

Question 35

35) graph with 4 declining lines

Answer 35

all the above

Question 36

what is a issue in ecology that Frank Preston explain with the concept of veil line?

Answer 36

sampling is imperfect & rarest species are missed

Question 37

how is complex trophic webs more stable?

Answer 37

because it has less reliance on a single resource

Question 38

unprofitable prey is mostly based on what fact?

Answer 38

that some prey are too hard to catch & may not be worth pursuing

Question 39

39) food web of fish & dragonfly

Answer 39

all of the above

Question 40

40) what can be said about rarefaction curve of a & b?

Answer 40

community a potentially has higher diversity than b

Question 41

what is the key difference between exponential & logistic models of population growth?

Answer 41

unlike exponential, logistic include the concept of carrying capacity

Question 42

write the definition of metapopulation

Answer 42

a group of subpopulations that exchange members through immigration & emigration

Question 43

W4) what are the black line & gray portion on the bell shape graph?

Answer 43

• veil line

- rare species missed from sampling

Question 44

name 2 key aspect of a sampling protocols that will ensure a good representation sample of species present in the area

Answer 44

a large sample size & area

Question 45

write the definition of carrying capacity

Answer 45

the maximum population size that a environment can support