Logical Reasoning

PT134 · S1 · Q8 According to the

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According to the "bottom-up" theory of how ecosystems are structured, the availability of edible plants is what primarily determines an ecosystem's characteristics since it determines how many herbivores the ecosystem can support, which in turn determines how many predators it can support.

Evidence

The availability of edible plants in an ecosystem is what determines how many herbivores the ecosystem can support.

The number of herbivores determines how many predators an ecosystem can support.

Intermediate Conclusion

The availability of edible plants is what primarily determines an ecosystem’s characteristics.

Main Conclusion

A reduction in the number of predators will have little impact on the rest of the ecosystem.

Evaluate

The theory’s assertion that the number of predators will have little impact on the rest of the ecosystem does not follow from the intermediate conclusion that the number of edible plants primarily determines an ecosystem’s characteristics. It could be that the primary influence is the number of edible plants, while the number of predators also has a significant influence on the rest of the ecosystem.

8.

Which one of the following, if true, would provide evidence against the bottom-up theory?

  1. In an effort to build

    Strengthen

    This supports the bottom-up theory because it shows that the number of edible plants can impact the rest of the ecosystem.

    1% picked this

  2. Correct

    After hunting virtually eliminated predators

    Why this is right

    This provides a counterexample to the theory and shows that a reduction in the number of predators had a significant impact on the rest of the ecosystem.

    Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

    85% picked this

  3. After many of the trees

    Strengthen

    This supports the bottom-up theory because it shows that the number of edible plants can impact the rest of the ecosystem.

    4% picked this

  4. After a new species of

    Strengthen

    This supports the bottom-up theory because it provides an example of the ecosystem depending on the number of edible plants.

    5% picked this

  5. Plants that are a dietary

    Too Weak

    While this seems to decouple the relationship between the number of edible plants and pigs, it only shows that an increase in edible plants does not always result in a larger population of an animal that feeds on that edible plant. This has no impact on the assertion that a decrease in predators would have little impact on the rest of the ecosystem, since Jaevix Island did not experience a reduction in the number of predators.

    5% picked this

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