Logical Reasoning

PT138 · S4 · Q24 Mammals cannot digest cellulose

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Mammals cannot digest cellulose and therefore cannot directly obtain glucose from wood.

Evaluation

Too much stuff here to diagram. We'd be better served trying to get a rough sense of all the facts and then coming back to the paragraph as needed once we see what type of idea each answer is floating us.

Humans can't eat wood, turning its cellulose in to glucose, but mushrooms can.

Mushrooms use that to make polymers called B-G's, which can be used to fight cancer (the more branches, the better B-G's fight cancer) by increasing immune-cell activity, not by killing cancer cells.

Goal

I wouldn't expect an answer to tie all this stuff together, but if we were trying it might sound like, .

Overall, though, we should just be wary of extreme wording in the answers and research the promising ones.

24.

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

  1. Mammals obtain no beneficial health

    Strong: obtain no healthy benefit

    In order to support this, we'd have to know that the only way to get healthy benefit from eating cellulose is by digesting it, and we were never told that.

    4% picked this

  2. If extracts from a type

    Backwards

    We know that "if a mushroom can use the cellulose to make B-G's, we might be able to make an extract that would fight tumors". This answer is saying, "If we make a tumor-fighting extract, it must be that the mushroom use cellulose." That's too strong in that direction. There might be other extracts from mushrooms that also fight tumors.

    16% picked this

  3. Correct

    The greater the degree of

    Why this is right

    This combines two ideas: the more branching, the more anti-tumor activity + the anti-tumor activity isn't killing cancer cells, it's increasing immune-cell activity

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

    65% picked this

  4. Immune-cell activity in mammals does

    Unsupported Relationship

    We know that the beta-glucan extracts fight cancer by increasing immune-cell activity, not by directly killing cancer cells. But it could still be the case that immune-cells fight cancer by killing cancer cells. Maybe beta-glucans increase immune-cell activity, the immune cells prevent tumor growth by killing cancer cells, and that is the means by which beta-glucans prevent tumor growth (indirectly).

    10% picked this

  5. Any organism capable of obtaining

    Too Strong

    We only know that some mushrooms can obtain glucose from wood to make beta-glucans. We can't assume that every single organism that can get glucose from wood also has this power to make beta-glucans.

    3% picked this

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