#21 - A geologist recently claimed to have discovered in clay

[Administrator]

Complete Question Explanation

Weaken. The correct answer choice is (B).

Answer choice (A):

Answer choice (B): This is the correct answer choice.

Answer choice (C):

Answer choice (D):

Answer choice (E):

This explanation is still in progress. Please post any questions below!

[letsdothis]

Weakening Qn

Answer choice (A): complicated doesn't equivocate to small. Also, sexual TYPE of reproduction is a TYPE. doesn't speak to all reproductive mechanism.

Answer choice (B): Correct. The objection is they can't have a reproductive mechanism so they can't be true living things. This speaks to the fact that smallest simplest structures can come together to form a reproductive mechanism. Hence, undermining the stimulus.

Answer choice (C): not enough info. do these have a reproductive mechanism? plus, mars?

Answer choice (D): It's pointing to the part that reproductive mechanism is prereq for life. But WE are not given any info if this is a previous definition or current. So irrelevant.

Answer choice (E): very out of scope

[atierney]

Hi Let's do this,

Yes! I agree we can basically eliminate all the answers (pretty easily) except for B and D, and as between the two, B directly addresses (and weakens) the main premise used for the argument, whereas D, aside from it being unclear as to which definition of life the stimulus uses (current or a previous one), also doesn't provide any explanation of how the definition of life hinges upon the visibility of microscopes or how the reproductive portion of the definition of life would be altered given the microscope... maybe the nanobes might only put on a "show" when viewed in a certain light... but I digress...

B is the best answer, and hopefully this is fairly clear given the irrelevance of the other answers.

[clbrogesr]

One thing that threw me for a loop with this Q is that I was always told that strengthen/weaken Qs never attack the premises themselves, but rather the relationship between the premises or the premises and the conclusion. In other words, I was always told not to question the premises, only the relationships created between them.

But this weaken question directly attacks one of the premises. One of the premises says that a reproductive mechanism is a prerequisite for life, and answer choice B directly contradicts that. I completely see why B is the right answer choice - but is my understanding of the solidity of the premises wrong then, or am I missing something in this question? In other words, am I wrong to see answer choice B as directly attacking a premise, as opposed to a relationship between premises/conclusions?

[sidneythomas1222@gmail.com]

Hi PowerScore,

Is it expected that test takers should know that bacteria are single-celled organisms? I narrowed the answer choices to B & D quickly, but when crunched for time I eliminated B because I reasoned that the stimulus never mentioned that bacteria or "nanobes" are single-celled organisms.

[Adam Tyson]

clbrogesr, answer B actually doesn't attack the premises. Rather, it tells us that these little nanobes COULD have a reproductive mechanism, even if they cannot contain one entirely within themselves. If they can band together to form such a mechanism, then they can meet that prerequisite for life!

sidneythomas1222@gmail.com, I'll say "yes and no" to your question. On the one hand, yes, LSAC expects us to know that bacteria are single-celled. They would consider that "common knowledge: that is fair game to test. But also, we don't NEED to know that in order to pick the correct answer. Answer B gives us a way that SOME creatures can form a reproductive system when they don't contain one within themselves, and if they can do it, maybe these nanobes can, too? That idea - that a reproductive mechanism can exist in this way - is enough to weaken the argument. Nanobes might be alive after all!

[maedayoku]

I correctly chose B, but found C to be attractive at the same time. If bacteria remains at Mars are the same size as nanobe, and we know that bacteria are living things, doesn't it weaken the argument? Or maybe C is incorrect because it is just some scientists' claim and we don't know if it is actually true?

[Rachael Wilkenfeld]

Hi maedayoku,

Good question! There are a couple of problems with answer choice (C). First, as you point out, answer choice (C) doesn't establish that there are bacteria in the meteorites, just that some scientists believe there are. Additionally, it mentions the fossilized remains of bacteria, which are different than intact bacteria. It could be small parts of bacteria instead of the full bacterium, which would explain the smaller size.

Hope that helps!

[TootyFrooty]

I did not choose the correct answer because it mentions nothing about single cell. Can you please share why B and not C? and expand on this further please?

[Dana D]

Hey Tooty,

Some of the previous answers here cover issues with answer choice (C) - I'll just add that an additional reason this answer choice fails to weaken the stimulus is that we are talking about living things, and we have no knowledge of life on Mars, so any comparison to bacteria from that planet wouldn't necessarily help us.

Furthermore, with weakening questions we want to attack the conclusion - in this case that is the idea that nanobes cannot be living things because they're too small to have a reproductive system.

Answer choice (B) successfully weakens this assertion that nanobes cannot be living things based on this reason by providing an example of how another, very small organism, became temporarily larger in order to reproduce, implying that nanobes could do the same.