Biology, Eighth Edition (Raven)

Chapter 56: Community Ecology

Post Test

Which of the following evidence supports the individualistic concept of a community? (p. 1169 )
A)The abundance of species varies independently along a geographical gradient.
B)Observations from the fossil record show a different species composition in the past in the same place.
C)There are no abrupt transitions between communities.
D)all of the above
Two species of bird found on two different islands in an archipelago have identically-sized beaks and eat similar seeds. What would you predict about the evolution of beak size if you transplanted both of these two species to a new island that was uninhabited by similar birds? (p. 1173)
A)There would be no change in the beaks of either species.
B)The beak size of one of the species would change, becoming either larger or smaller on average.
C)One of the species would go extinct.
D)The beak sizes of both species would diverge from each other and from their original sizes.
Which of the following predictions are true regarding Batesian mimicry? (p 1177)
A)They should be relatively rare compared to their model.
B)There will be selection for polymorphism in the mimic to enable it to mimic more than one model.
C)There will be constant selection for the mimic to resemble the model more and more closely.
D)all of the above
E)none of the above - these predictions apply to Mullerian mimicry
Keystone species play an especially important in a community because they may: (p.1183)
A)be food for many different species.
B)be predators and prevent one species from outcompeting another.
C)manipulate the environment in ways that create new habitat for other species.
D)both b and c
Why is disturbance of communities thought to increase species diversity? (p.1186)
A)It may prevent the final stage of succession from being reached.
B)Patches of habitat will exist at different successional stages with different compositions of species.
C)An equilibrium state will never be reached.
D)all of the above
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