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Bio 212 Exam 4 Questions with Correct Answers |
Updated (100% Correct Answers)
Reciprocal evolutionary change between interacting species, driven by natural
selection. Answer: Coevolution
A relationship between species in which both species benefit. Answer: Mutualism
Nutritious, lipid-rich appendages on seeds that attract ants. Answer: Elaiosomes
Ants collect seeds that have elaiosomes, eat the elaiosomes, and plants have
their seeds dispersed. Answer: Seed Dispersal
Some wrass species clean mouths of moray eels, providing food for wrass and
removing debris for eels. Answer: Cleaners
Joshua Trees are only pollinated by yucca moths, which feed on Joshua tree
seeds. Answer: Pollinators
A relationship in which one species benefits and the other species is harmed.
Answer: Antagonism
Example: Black bear (Ursus americanus) with a salmon. Answer: Predator/prey
Example: Desert cottontail (Sylvilagus audubonii) eating vegetation. Answer:
Herbivore/plant
Orchids mimic female wasps to attract male wasps for pollen transfer. Answer:
Deceptive pollination
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Example: Brown-headed cowbirds lay eggs in nests of other birds. Answer:
Parasite/host
Some hosts incubate cowbird eggs and feed cowbird young; behaviors can
change based on frequency of brood parasitism. Answer: Brood Parasitism
A relationship between species in which one species benefits and the other
species neither benefits nor is harmed. Answer: Commensalism
Benefits by being transported to new feeding grounds; nudibranch is not
harmed. Answer: Emperor shrimp
Both species are harmed because they are using the same limited resource (food,
space, mates, etc.). Answer: Competition
Two species of finches competing for the same seed size. Answer: Example of
Competition
One species is harmed, while the other is unaffected. Answer: Amensalism
A plant releasing chemicals that kill nearby seedlings but gaining no direct
benefit. Answer: Example of Amensalism
Both species have no significant effect on one another. Answer: Neutralism
An evolutionary outcome caused by competition, leading to traits diverging in
species. Answer: Character displacement
Many species evolve from a common ancestor and specialize on different niches.
Answer: Adaptive radiation
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The classification of an interspecific interaction (mutualism, commensalism,
antagonism, etc.) is not fixed and can change over time as more information is
gathered. Answer: Interspecific interaction
Environmental changes can shift costs and benefits, altering the interaction type.
Answer: Environmental changes
Parasite-host coevolution occurs through a repeating cycle of adaptation and
counter-adaptation, often described as a coevolutionary arms race or cyclic (Red
Queen) dynamics. Answer: Parasite-host coevolution
When a parasite infects a host population, it reduces host fitness, creating strong
selection for host individuals that carry defensive traits. Answer: Host fitness
These mutations spread, increasing the frequency of resistant genotypes.
Answer: Beneficial host mutations
Describes the strength of selection that occurs in two species due to their
interactions with one another. Answer: Reciprocal selection
The selective value of a trait depends on its abundance. Answer: Frequency
dependent selection
Fitness decreases when a trait is common; example: brood parasites. Answer:
Negative frequency dependent selection
Fitness increases when a trait is common; example: Mullerian mimicry
(bees/wasps). Answer: Positive frequency dependent selection
© 2026 All rights reserved
Bio 212 Exam 4 Questions with Correct Answers |
Updated (100% Correct Answers)
Reciprocal evolutionary change between interacting species, driven by natural
selection. Answer: Coevolution
A relationship between species in which both species benefit. Answer: Mutualism
Nutritious, lipid-rich appendages on seeds that attract ants. Answer: Elaiosomes
Ants collect seeds that have elaiosomes, eat the elaiosomes, and plants have
their seeds dispersed. Answer: Seed Dispersal
Some wrass species clean mouths of moray eels, providing food for wrass and
removing debris for eels. Answer: Cleaners
Joshua Trees are only pollinated by yucca moths, which feed on Joshua tree
seeds. Answer: Pollinators
A relationship in which one species benefits and the other species is harmed.
Answer: Antagonism
Example: Black bear (Ursus americanus) with a salmon. Answer: Predator/prey
Example: Desert cottontail (Sylvilagus audubonii) eating vegetation. Answer:
Herbivore/plant
Orchids mimic female wasps to attract male wasps for pollen transfer. Answer:
Deceptive pollination
© 2026 All rights reserved
,2
Example: Brown-headed cowbirds lay eggs in nests of other birds. Answer:
Parasite/host
Some hosts incubate cowbird eggs and feed cowbird young; behaviors can
change based on frequency of brood parasitism. Answer: Brood Parasitism
A relationship between species in which one species benefits and the other
species neither benefits nor is harmed. Answer: Commensalism
Benefits by being transported to new feeding grounds; nudibranch is not
harmed. Answer: Emperor shrimp
Both species are harmed because they are using the same limited resource (food,
space, mates, etc.). Answer: Competition
Two species of finches competing for the same seed size. Answer: Example of
Competition
One species is harmed, while the other is unaffected. Answer: Amensalism
A plant releasing chemicals that kill nearby seedlings but gaining no direct
benefit. Answer: Example of Amensalism
Both species have no significant effect on one another. Answer: Neutralism
An evolutionary outcome caused by competition, leading to traits diverging in
species. Answer: Character displacement
Many species evolve from a common ancestor and specialize on different niches.
Answer: Adaptive radiation
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, 3
The classification of an interspecific interaction (mutualism, commensalism,
antagonism, etc.) is not fixed and can change over time as more information is
gathered. Answer: Interspecific interaction
Environmental changes can shift costs and benefits, altering the interaction type.
Answer: Environmental changes
Parasite-host coevolution occurs through a repeating cycle of adaptation and
counter-adaptation, often described as a coevolutionary arms race or cyclic (Red
Queen) dynamics. Answer: Parasite-host coevolution
When a parasite infects a host population, it reduces host fitness, creating strong
selection for host individuals that carry defensive traits. Answer: Host fitness
These mutations spread, increasing the frequency of resistant genotypes.
Answer: Beneficial host mutations
Describes the strength of selection that occurs in two species due to their
interactions with one another. Answer: Reciprocal selection
The selective value of a trait depends on its abundance. Answer: Frequency
dependent selection
Fitness decreases when a trait is common; example: brood parasites. Answer:
Negative frequency dependent selection
Fitness increases when a trait is common; example: Mullerian mimicry
(bees/wasps). Answer: Positive frequency dependent selection
© 2026 All rights reserved
