Bio 250 Final Exam Questions And All
Correct Answers.
What is community ecology? - Answer the study of interactions between species and how they
influence community structure and function
Ecologists define a community as: - Answer species within a particular place that interact or potentially
interact
Disturbance: - Answer A discrete event that disrupts an ecosystem or community
Succession: - Answer the repeatable change in community composition through time following a
disturbance
Succession is affected by: - Answer self thinning, life history traits
Primary succession: - Answer initial establishment of a community
Secondary succession: - Answer re-establishment of existing community
What are the 3 models of succession? - Answer facilitation, tolerance, inhibition
What is facilitation? - Answer When one species opens up niches for other species to grow, stress-
tolerant species make it more habitable
What is inhibition? - Answer whoever gets there first survives, inhibits growth of other colonies
What is tolerance? - Answer whoever gets there first survives, but has no effect on other species
What is a climax community? - Answer succession progresses towards this, seen as a stable endpoint
,What are allogenic processes? - Answer outside influences that effect communities such as human
interventions, immigration by new species, seasonal changes, abiotic disturbances
What is an example of an allogenic process? - Answer human interventions, immigration by new
species, seasonal changes, abiotic disturbances
What do allogenic processes ensure? - Answer That a community is almost never in equilibrium
Intermediate disturbance hypothesis: - Answer species diversity will be greatest when disturbances are
of intermediate frequency, when an intermediate amount of time has passed after a disturbance, or
when the disturbance is of intermediate magnitude
Most species live at ___ amounts of disturbance. - Answer intermediate
Direct benefit: - Answer from the source to the other thing
Indirect benefit: - Answer from the source to another thing and then the other thing
Where does the flow of energy begin? and with who? - Answer the first trophic level, primary
producers
What occupies the second trophic level? - Answer herbivores
What occupies the third trophic level? - Answer predators
What occupies the fourth trophic level? - Answer animals that feed directly on predators
Primary consumers only get about ___ of the energy of the producers. - Answer 10%
, What is top-down control? - Answer higher trophic level limits the size of the trophic level they
consume
Predation limits ___ and releases pressure on ___. - Answer herbivores, vegetation
When a predator is removed, number of herbivores ___ and vegetation ___. - Answer increases,
decreases
what is a behavioral cascade? - Answer where a predator indirectly stimulates primary production by
altering the foraging behavior of its prey
autogenic engineer (indirect): - Answer result from the internal architecture of the engineer itself
(corals, trees)
allogenic engineers (indirect): - Answer result from the redistribution of living or non-living materials
(beaver dams)
Bottom-up hypothesis: - Answer organisms at each trophic level are resource-limited; food-chain
length increases as resource-availability increases
What is an example of the bottom-up hypothesis? - Answer crop production increases when fertilizer
(nutrients) are applied
Even when production is high ___ may limit higher trophic levels because many plants are low quality
food. - Answer bottom up control
Productivity hypothesis: - Answer more productive ecosystems should have longer food chains
ex) lakes with higher P concentrations would have longer food chains but that lake size wouldn't matter
ecosystem size hypothesis: - Answer food chain length should increase with ecosystem size
ex) larger lakes would have longer food chains but that P concentration wouldn't matter
Correct Answers.
What is community ecology? - Answer the study of interactions between species and how they
influence community structure and function
Ecologists define a community as: - Answer species within a particular place that interact or potentially
interact
Disturbance: - Answer A discrete event that disrupts an ecosystem or community
Succession: - Answer the repeatable change in community composition through time following a
disturbance
Succession is affected by: - Answer self thinning, life history traits
Primary succession: - Answer initial establishment of a community
Secondary succession: - Answer re-establishment of existing community
What are the 3 models of succession? - Answer facilitation, tolerance, inhibition
What is facilitation? - Answer When one species opens up niches for other species to grow, stress-
tolerant species make it more habitable
What is inhibition? - Answer whoever gets there first survives, inhibits growth of other colonies
What is tolerance? - Answer whoever gets there first survives, but has no effect on other species
What is a climax community? - Answer succession progresses towards this, seen as a stable endpoint
,What are allogenic processes? - Answer outside influences that effect communities such as human
interventions, immigration by new species, seasonal changes, abiotic disturbances
What is an example of an allogenic process? - Answer human interventions, immigration by new
species, seasonal changes, abiotic disturbances
What do allogenic processes ensure? - Answer That a community is almost never in equilibrium
Intermediate disturbance hypothesis: - Answer species diversity will be greatest when disturbances are
of intermediate frequency, when an intermediate amount of time has passed after a disturbance, or
when the disturbance is of intermediate magnitude
Most species live at ___ amounts of disturbance. - Answer intermediate
Direct benefit: - Answer from the source to the other thing
Indirect benefit: - Answer from the source to another thing and then the other thing
Where does the flow of energy begin? and with who? - Answer the first trophic level, primary
producers
What occupies the second trophic level? - Answer herbivores
What occupies the third trophic level? - Answer predators
What occupies the fourth trophic level? - Answer animals that feed directly on predators
Primary consumers only get about ___ of the energy of the producers. - Answer 10%
, What is top-down control? - Answer higher trophic level limits the size of the trophic level they
consume
Predation limits ___ and releases pressure on ___. - Answer herbivores, vegetation
When a predator is removed, number of herbivores ___ and vegetation ___. - Answer increases,
decreases
what is a behavioral cascade? - Answer where a predator indirectly stimulates primary production by
altering the foraging behavior of its prey
autogenic engineer (indirect): - Answer result from the internal architecture of the engineer itself
(corals, trees)
allogenic engineers (indirect): - Answer result from the redistribution of living or non-living materials
(beaver dams)
Bottom-up hypothesis: - Answer organisms at each trophic level are resource-limited; food-chain
length increases as resource-availability increases
What is an example of the bottom-up hypothesis? - Answer crop production increases when fertilizer
(nutrients) are applied
Even when production is high ___ may limit higher trophic levels because many plants are low quality
food. - Answer bottom up control
Productivity hypothesis: - Answer more productive ecosystems should have longer food chains
ex) lakes with higher P concentrations would have longer food chains but that lake size wouldn't matter
ecosystem size hypothesis: - Answer food chain length should increase with ecosystem size
ex) larger lakes would have longer food chains but that P concentration wouldn't matter
