Question

Which of the following, if true, would most clearly support the argument about keystone status advanced in the last sentence of the passage (lines 99342 - 42146) ?

• A. A species of bat is primarily responsible for keeping insect populations within an ecosystem low, and the size of the insect population inturn affects bird species within that ecosystem
• B. A species of iguana occupies a keystone role on certain tropical islands, but does not play that role on adjacent tropical islands that are inhabited by a greater number of animal species.
• C. Close observation of a savannah ecosystem reveals that more species occupy keystone roles within that ecosystem than biologists had previously believed.
• D. As a keystone species of bee becomes more abundant, it has a larger effect on the ecosystem it inhabits.
• E. A species of moth that occupies a keystone role in a prairie habitat develops coloration patterns that camouflage it from potential predators.

Answer 1

The correct option is B A species of iguana occupies a keystone role on certain tropical islands, but does not play that role on adjacent tropical islands that are inhabited by a greater number of animal species.

The passage talks about

As in the lines 12-16 it is clearly mentioned if in particular geography if some species are dominant than other remaining, leads to dominant one into keystone status. But if the adjacent areas are dominated by a greater number of other animal species then keystone status changed. Since the iguana species play a keystone role in tropical islands as they are dominant there but not to adjacent tropical islands where other animal species are more in number.

As in the passage, the ecosystem is a crucial system where different species occupies there own role. The species whose effects are much more on the ecosystem can also play a vital role. If any species is removed or if there would be any changes in the ecosystem then it leads to a problem. Here in this passage also, the importance of every species is mentioned that every species play a vital role in the ecosystem . If any species are dominant then they lead to keystone roles. Every newly arrived species creates or affect the ecosystem differently.