Q5 - Bacteria that benefit human

[randitect]

I had trouble with C, D and E... can someone please explain those three answer choices? Thank you.

[tommywallach]

Hey Randy,

Whenever you're doing one of these WEAKEN questions, it's important to locate the core for yourself, and attempt to see the problem with the argument. Because these are all assumption based questions, there will always be a flaw.

Conclusion: Pylori isn't a commensal
Premise: Pylori does bad stuff to 10%, good stuff to everyone; M.T. does bad stuff to 10%, and isn't called a commensal

The problem here is that Pylori is called a commensal IN SPITE of the bad stuff it does, because it does good stuff to everyone ("strengthens immune response"). Comparing it to something where we don't know if it does good stuff or not isn't helpful. To weaken, we just need evidence that M.T. doesn't do anything good, in which case it's silly to compare it to Pylori, which DOES do good stuff.

(A) Treatment is irrelevant. Whether or not something is a commensal is purely about whether it "benefits human beings"

(B) Again, the time it lasts is irrelevant.

(C) Uh oh. If M.T. doesn't do anything good, then you can't use it as a benchmark for calling Pylroi a non-commensal. CORRECT!

(D) The number of people who have them is irrelevant. We care about the percentage of people with them who derive benefits or suffer affliction. Even if only one person had a given bacteria, if it did good things, it would be legitimate to call it a commensal (based on the definition in the first sentence).

(E) Same as (D).

Hope that helps!

-t

[tara_amber1]

For a #5, I'm so confused on the reasoning behind this. It seems like (C) doesn't do anything for the argument because if we're told that M isn't considered a commensal, we already know that it doesn't have any benefits. The argument concludes that it's wrong to consider H a commensal by example of M which has some bad stuff, and no benefits. So we shouldn't call H a commensal just because it has bad stuff and some benefits.

Would the argument be more solid if M also had a benefit, and still isn't called a commensal? Because then I could see how calling H a commensal would be misguided. However, since it's not the case that M has a benefit, deciding whether H is a commensal or not on the basis of M isn't strong?

I feel like the way this argument is structured as well as the correct answer choice that goes with it is way different from any other weaken questions I've ever encountered. Can someone explain this in English to me please? I really need it dumbed down.

[ohthatpatrick]

This IS a weirdly dense #5. Normally I expect to see these science heavy Strengthen/Weaken questions in the late teens.

The underlying argument archetype is a very common one though.

This is an argument by analogy.

In an argument by analogy, you basically say:
Because A and B both have X in common,
we can conclude that A and B both have Y in common.

In this case:
Because HP and MT both cause sickness in 10% of cases,
we can conclude that HP and MT should both NOT be referred to as commensals.

Any time you see an argument by analogy, you can:
- Strengthen the argument by showing that A and B have more stuff in common
- Weaken the argument by pointing out a significant difference between A and B

For example, if I argued:
Taking a full length LSAT and running a full 26 mile marathon both require a lot of endurance. Since marathon runners never run 26 miles during their training, LSAT students should never take full practice tests in their training.

How would you defend your right to take a full length practice test?

You'd probably say something about the differences between LSAT taking and marathon running:
- taking an LSAT doesn't require nearly as much endurance as a marathon
- LSAT requires mental endurance, while marathon running requires muscular and cardiovascular endurance.
etc.

So all you would need to look for in the answer choices is some important different between HP and MT.

As you surmised, if we wanted to strengthen this argument, we would want HP and MT to sound MORE the same, so an idea such as "MT is also allegedly something that can strengthen the immune system" would be a great Strengthen answer.

(A) is irrelevant, but all I would read is "SAME".

(B), (C), (D), and (E) all introduce differences between HP and MT.

However, since the ultimate judgment is whether we should call HP a commensal, "a beneficial bacteria", (C) is by far the most relevant.

In my previous LSAT/marathon argument, I could give irrelevant differences between them in trap answers (that don't relate to whether one should take a full length practice LSAT).

(A) Marathons only happen in the spring and summer months, while LSAT is administered once per season.

(B) The average entry fee for a marathon is less than the cost of taking the LSAT.

etc.

Hope this helps

[obobob]

Hi ohthatpatrick

Would you mind sharing any of your insight in solving this question quickly? I get the logic of the stimulus and why the correct answer is correct, but it literally took me aa very long time to approach the correct answer as I wrote down all the conditions down on a separate paper.

Best,