Logical Reasoning

PT110 · S3 · Q22 Viruses can have beneficial effects

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Viruses can have beneficial effects.

Statements

Viruses can have beneficial effects (such as killing a more-complex microorganism that could be deadly to humans).

Viruses have very simple structures; you could take a beneficial virus, replace a few of its several million atoms, and turn it into a deadly virus.

Random mutations can result is alterations like this (even more complex ones), so any virus could easily become dangerous to humans.

Evaluate

Normally on Must Be False, the correct answer either 1. contradicts a conditional 2. contradicts a Must Be True inference we can make by combining claims

There's a conditional in the final sentence, since we hear that all viruses could be come dangerous to humans. So there may be a correct answer that talks about a virus that is purely harmless.

Can we combine claims to derive anything? Is there any Overlapping Concept? The idea "virus" shows up in several claims, so we could say silly things like , combining two things we know about viruses.

Goal

Let's find an answer we can contradict.

22.

If the statements above are true, then each of the following statements could also be true EXCEPT:

  1. Random mutation makes some deadly

    Compatible

    We hear that random mutation could switch a few atoms and turn a beneficial virus into something deadly. It seems like random mutation could switch a few atoms and turn a deadly virus into a beneficial one. We certainly can't contradict this. We would need proof that "random mutation can never turn a deadly virus into a beneficial one".

    13% picked this

  2. Some organisms of greater complexity

    Compatible

    This is saying that an organism of greater complexity than a virus may be less likely to undergo a significant alteration through mutation. That seems very possible, if not likely. Contradicting this answer would mean that in the passage we learned that "every organism of greater complexity than a virus is more likely than a virus to undergo significant alternations through mutation". We certainly were provided with no information that we could apply to "every organism of greater complexity than a virus".

    9% picked this

  3. Some microorganisms that are more

    Compatible

    It's certainly possible that there is at least one microorganism more complex than a virus that is beneficial to humans. To contradict this, we would have needed to have been told that "all microorganisms that are more complex than a virus are either neutral or damaging to humans".

    4% picked this

  4. Some viruses that fail to

    Out of Scope: virus killing virus

    We don't have any information at all on the subject of this sentence (viruses that fail to kill other viruses), so we can't contradict it. To contradict this, we would have needed to have been told that "every virus that fails to kill a virus that's deadly to humans is either neutral or damaging to humans".

    8% picked this

  5. Correct

    No virus that is deadly

    Why this is right

    All four of the other answers had weak, watered-down "some" language. Those are scary answers on Must Be False, because to contradict "some" you need to prove "none". As we considered each of those four answers, we thought about how extreme the contradiction idea would be. Here, they're giving us an extreme idea, which is much easier to contradict, because you only need one exception to do so. If someone says "No men like ballet", you only need one man who likes ballet to contradict that. Since this says, "No virus that's deadly to more-complex organisms is beneficial to humans", we can contradict it if we have one example of a virus that's deadly to more-complex organisms that is also beneficial to humans. The first two sentences give us that. Some viruses kill more-complex organisms (they are deadly to organisms of greater complexity than themselves) and are beneficial to humans.

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

    67% picked this

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