Logical Reasoning

PT121 · S1 · Q25 Almost all microbe species live

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Almost all microbe species live together in dense, interdependent communities, supporting the environment for each other, and regulating the population balances for their different species through a complex system of chemical signals.

Conclusion

Microbiologists lack complete knowledge of most microbe species.

Evidence

Most microbe species live in dense / complexly intertwined systems, and thus it is currently impossible to cultivate any one such species in isolation.

Evaluate

On Sufficient Assumption, if we see a New Term in the conclusion, we know it will be in the correct answer. Here, that term is "lack complete knowledge".

Were we given some rule that says ?

Nope. So the correct answer needs to provide that rule.

What are the salient things we know about most microbe species that would sound like it leans towards "lack complete knowledge"?

We heard they .

That second fact is more negative sounding (i.e. sounds more like the negative of "lack knowledge") and it's at the end of the chain of the Premise's reasoning.

Goal

So we should be expecting something like,

If it's impossible lack complete to cultivate any → knowledge of species one such species in isolation

25.

Which one of the following, if assumed, enables the argument's conclusion to be properly drawn?

  1. It is currently impossible for

    Unrelated to Goal

    If it doesn't say "lack complete knowledge", it's not really useful to us, since our job here is to derive the idea that microbiologists lack complete knowledge of most microbe species.

    5% picked this

  2. If it is currently impossible

    Unrelated to Goal

    If it doesn't say "lack complete knowledge", it's not really useful to us, since our job here is to derive the idea that microbiologists lack complete knowledge of most microbe species.

    7% picked this

  3. Correct

    No microbiologist can have complete

    Why this is right

    This sounds a lot like our prediction: If a microbiologist can't cultivate a species in isolation, then a microbiologist can't have complete knowledge of a species. We know that most microbe species can't be cultivated in isolation, so this rule allows us to derive that microbiologists lack complete knowledge of most microbe species.

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

    80% picked this

  4. At least some microbiologists lack

    Too Weak

    We know that most microbe species live together in dense, interdependent communities, so this answer allows us to derive that "at least some microbiologists lack complete knowledge of most microbe species". But the conclusion is that all microbiologists lack complete knowledge, so this doesn't quite get us there.

    4% picked this

  5. No microbe species that normally

    Unrelated to Goal

    If it doesn't say "lack complete knowledge", it's not really useful to us, since our job here is to derive the idea that microbiologists lack complete knowledge of most microbe species.

    4% picked this

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