Logical Reasoning

PT159 · S3 · Q19 When plants are growing quickly, they take more carbon dioxide

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When plants are growing quickly, they take more carbon dioxide out of the atmosphere than they release into it.

Given

When plants grow fast, they take more CO2 out of the atmosphere than they release.

When plants grow very slowly, they release more CO2 than they take out.

Any substantial increase in CO2 causes temperatures to increase in the tropics.

The bulk of Earth's plants are in the tropics.

The more temperatures increase in the tropics, the more slowly, on average, plants there grow.

Evaluate

All the Causal statements should prompt us to look for opportunities to chain them together. Only claim 1 mentions fast plant growth and taking more CO2 out, so that one won't chain to anything else. Claim 2 tells us that very slow plant growth causes more CO2 to be released. That doesn't necessarily chain to claim 3, because releasing more CO2 doesn't necessarily create a substantial increase, but in cases where it does, it would increase the temperature in the tropics. That chains to the final claim, resulting in slower average plant growth.

Goal

Look for an answer that articulates all or part of our Causal Chain:

Very Slow Plant Growth > Releases CO2

Lots more CO2 > Increase Tropic Temps > Slower Ave. Growth of Tropics Plants

Beware answers that are too strong or that ignore important modifiers (substantial increase, very slow growth, etc).

19.

Which one of the following is most strongly supported by the information above?

  1. The amount of carbon dioxide

    Too Strong: inevitably

    "Inevitably" is a red flag in Most Supported questions, especially those that are not testing Conditional Logic. We also don't have any information about anything "gradually accelerating."

    3% picked this

  2. If the amount of carbon

    Unsupported Causal Relationship

    A substantial increase in CO2 emissions will increase the temperature in the tropics, and that is where the bulk of Earth's plant's live, so the first half of this answer sounds like it could be correct. However, in order to say that those plants will release more CO2 than they take out, we'd need to know that they are growing very slowly. And while a substantial increase in CO2 will cause higher tropic temperatures which will in turn slow the growth of plants there on average, we can't say that it will slow them to the point where they are growing very slowly. Thus, this answer is tempting, but incorrect.

    26% picked this

  3. Correct

    Plants in the tropics will

    Why this is right

    This reflects a link in our Causal Chain: Lots more CO2 > Increase Tropic Temps > Slower Ave. Growth of Tropics Plants

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

    49% picked this

  4. If the plants in the

    Reversal: last claim

    This answer is just a reversal of the last claim in the stimulus.

    12% picked this

  5. Any increase in temperatures in

    Reversal: second-to-last claim

    This answer is just a reversal of the second-to-last claim in the stimulus.

    10% picked this

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