JMU BIO 250 REIDER FINAL EXAM WITH ALL CORRECT
& VERIFIED ANSWERS (UPDATED TO PASS)
Community Dynamics Correct answer-community ecology examines how species interactions
influence structure and function
Disturbance Correct answer-alters a community by killing organisms, altering resource/substrate
availability, and changing the physical structure of the environment from forces originating OUTSIDE
the community
Succession Correct answer-relatively repeatable change in community composition through time
following a disturbance, driven by INTERNAL dynamics
primary succession Correct answer-initial conditions, bare ground, no seed bank
secondary succession Correct answer-seed bank or roots
Facilitation Correct answer-- uninhabitable by all except the most stress tolerant species.
- colonists facilitate/make environment more suitable to successive species
Inhibition Correct answer-all species that arrive CAN survive BUT colonists inhibit growth of later
arrivals until they die
Tolerance Correct answer-all species that arrive CAN survive, and late arriving species tolerate
early species because better competitors
climax community Correct answer-a stable community that no longer goes through major
ecological changes
autogenic processes Correct answer-- INTERNAL dynamics
- drives towards stable, unchanging equilibrium
allogenic processes Correct answer-Outside influences that ensure communities are almost never
in equilibrium
intermediate disturbance hypothesis Correct answer-species diversity is highest when frequency
and intensity of disturbances are intermediate
trophic levels Correct answer-1. primary producers (most energy)
2. Herbivores
3. Predators
4. Animals that eat predators
5. Top predator (least energy)
Trophic cascades Correct answer-top trophic level limits size of the level they consume
behavioral cascade Correct answer-where a predator, by altering the foraging behavior of its prey,
indirectly stimulates primary production
ecosystem engineers Correct answer-indirect affect community dynamics by modifying the
environment and altering resource availability
& VERIFIED ANSWERS (UPDATED TO PASS)
Community Dynamics Correct answer-community ecology examines how species interactions
influence structure and function
Disturbance Correct answer-alters a community by killing organisms, altering resource/substrate
availability, and changing the physical structure of the environment from forces originating OUTSIDE
the community
Succession Correct answer-relatively repeatable change in community composition through time
following a disturbance, driven by INTERNAL dynamics
primary succession Correct answer-initial conditions, bare ground, no seed bank
secondary succession Correct answer-seed bank or roots
Facilitation Correct answer-- uninhabitable by all except the most stress tolerant species.
- colonists facilitate/make environment more suitable to successive species
Inhibition Correct answer-all species that arrive CAN survive BUT colonists inhibit growth of later
arrivals until they die
Tolerance Correct answer-all species that arrive CAN survive, and late arriving species tolerate
early species because better competitors
climax community Correct answer-a stable community that no longer goes through major
ecological changes
autogenic processes Correct answer-- INTERNAL dynamics
- drives towards stable, unchanging equilibrium
allogenic processes Correct answer-Outside influences that ensure communities are almost never
in equilibrium
intermediate disturbance hypothesis Correct answer-species diversity is highest when frequency
and intensity of disturbances are intermediate
trophic levels Correct answer-1. primary producers (most energy)
2. Herbivores
3. Predators
4. Animals that eat predators
5. Top predator (least energy)
Trophic cascades Correct answer-top trophic level limits size of the level they consume
behavioral cascade Correct answer-where a predator, by altering the foraging behavior of its prey,
indirectly stimulates primary production
ecosystem engineers Correct answer-indirect affect community dynamics by modifying the
environment and altering resource availability
