Q20

[mikeyjacobs]

Hey,

Question 20, Which one of the following is most strongly....

I don't see how the correct answer which is supposed to be strongly supported can be a choice that is not mentioned in the passage, can you explain this logic to me.

Thanks,

Mike

[aileenann]

Hi Mike,

Sometimes when a question asks what is most strongly supported by the information in the passage, it is asking you to make a logical inference based on the facts of the passage. That is, given what you know, what must certainly, or almost certainly, follow from the information. The correct answer here, (D), is largely supported by information from the first paragraph of the passage, particularly the following:

"discovery of the *first* of these agents"...where the chemicals are described earlier as those that regulate the performance of some specialized functions for nerve cells.

This is enough to tell us that there are other neurotrophic factors and that they perform functions distinct from those of NGF. I hope that helps. Please let me know if you have further questions on this problem!

[rpcuhk]

Hi Mike,

Sometimes when a question asks what is most strongly supported by the information in the passage, it is asking you to make a logical inference based on the facts of the passage. That is, given what you know, what must certainly, or almost certainly, follow from the information. The correct answer here, (D), is largely supported by information from the first paragraph of the passage, particularly the following:

"discovery of the *first* of these agents"...where the chemicals are described earlier as those that regulate the performance of some specialized functions for nerve cells.

This is enough to tell us that there are other neurotrophic factors and that they perform functions distinct from those of NGF. I hope that helps. Please let me know if you have further questions on this problem!

The second sentence of the first paragraph clearly support that there are other neurotrophic factors, but how do you infer that these neurotrophic factors perform functions that are not specifically identified in the passage?

[bbirdwell]

Here's how I think about this problem:

(A) No evidence for this; the author explains this only in terms of NGF.

(B) No evidence. We know nothing about how well understood other factors are -- the whole thing is about NGF.

(C) No evidence for this. The test-writers are hoping we will misread the first paragraph "..discovered the first of these factors." This suggests that there are other factors, but not necessarily that she discovered them.

(D) The function of NGF is described in lines 50 onward. The function of the other factors is never explained or mentioned -- they're not even named. The whole passage is about NGF.

(E) like (A), there's not support for this.

Hope that helps!

[rpcuhk]

(D) The function of NGF is described in lines 50 onward. The function of the other factors is never explained or mentioned -- they're not even named. The whole passage is about NGF.

Hope that helps!

Exactly! so how is D the correct answer choice?

[bbirdwell]

??

Because that's what (D) says: There are other factors. We know this because NGF is the "first." And their functions are not explained in the passage.

[rpcuhk]

??

Because that's what (D) says: There are other factors. We know this because NGF is the "first." And their functions are not explained in the passage.

Thanks for your reply! My point is since the functions of other neurotrophic factors are never explained in the passage, we don't know whether or not they perform the same function as NGF, which has already been identified in the passage. In that case we can't say that they perform functions that are not specifically identified in the passage, because such function has been identified. Therefore, D is not supported by the passage. I hope I've get my point across.

[bbirdwell]

I think you've kind of twisted in on yourself here, into a sort of mobius strip of logic, if you will.

Check this out, here's what you said that makes sense:

we don't know whether or not they perform the same function as NGF,

Exactly. Why not? Because the passage has not identified their function(s). This is (D).

[linzhu2]

I had a really hard time eliminating (B) here. Because NGF was the first neurotrophic factor identified and we know from the passage that subsequent factors have been discovered that perform certain unidentified specialized functions - couldn't we infer that these factors are now "more thoroughly understood" than they were before they were discovered? I suppose understanding comes after its discovered to exist and we don't know if we understand any other neutrophic factor more than we did after it was discovered?

I'm not really sure. Can anyone provide some insight as to why (B) wouldn't be correct? Thanks in advance.

[bbirdwell]

couldn't we infer that these factors are now "more thoroughly understood" than they were before they were discovered

I'd say know. Discovering them does not imply understanding them. And that isn't what the choice says, anyway. It says "more understood than NGF," not "more understood than they were in the past."

[acg912]

couldn't we infer that these factors are now "more thoroughly understood" than they were before they were discovered

I'd say know. Discovering them does not imply understanding them. And that isn't what the choice says, anyway. It says "more understood than NGF," not "more understood than they were in the past."

Couldn't one also read that statement as saying that some other factors are now more thoroughly known than they were at the time of NGF's discovery?

[dhlim3]

This question killed me. Picked B over D because there was no support in the passage that indicated that other neurotraffic factors played non-specified roles. But what's important is not whether these other factors perform different functions as NGF but whether their roles are specified at all in the passage. They weren't.

[KarlM387]

I can definitely see how D is a correct answer, but I am having trouble seeing how E can be considered incorrect. As detailed in the second paragraph, one effect of NGF observed in the chick embryo experiment was the regulation of nerve cells (as the presence of mouse tumor increased the nerve tissue growth). The first sentence of the passage seems to make it pretty clear that this regulation of nerve cells is an effect of neurotrophic factors in general - not just NGF. As these other neurotrophic factors are not discussed in the passage, it would follow that at least one effect of NGF (namely, nerve cell regulation) observed in the chick embryo experiement is caused by other factors not mentioned the passage. This is what answer E says (as best I can tell?)

What am I interpreting wrong here? Would "regulation of nerve cells” not actually be considered an effect of NGF/growth factors?

Thanks in advance for any help you can give!

[GordanC390]

I can definitely see how D is a correct answer, but I am having trouble seeing how E can be considered incorrect. As detailed in the second paragraph, one effect of NGF observed in the chick embryo experiment was the regulation of nerve cells (as the presence of mouse tumor increased the nerve tissue growth). The first sentence of the passage seems to make it pretty clear that this regulation of nerve cells is an effect of neurotrophic factors in general - not just NGF. As these other neurotrophic factors are not discussed in the passage, it would follow that at least one effect of NGF (namely, nerve cell regulation) observed in the chick embryo experiement is caused by other factors not mentioned the passage. This is what answer E says (as best I can tell?)

What am I interpreting wrong here? Would "regulation of nerve cells” not actually be considered an effect of NGF/growth factors?

Thanks in advance for any help you can give!

I have the very same idea with KarlM387 in my mind! To me (E) means there are other neurotrophic factors that have the same function of NGF (though the exact wording used in the answer is 'effect' rather than 'function', don't know if it matters) while (D) means there are other neurotrophic factors that have functions other than NGF. Just as stated in KarlM387's post, I can't see how (D) should be picked over (E).

[Laura Damone]

Such a tough question! The reason E is incorrect is that we don't know that the specific effects from the chick experiment can be caused by other neurotrophic factors. Do we know there are other neurotrophic factors? Absolutely. See lines 6 "the first of these substances" and 40 "NGF was the first of many." But we don't go into greater detail than that, other than to say that the other ones are also "found in the bodies of animals" (line 41). Do they function the same way as NGF? Would they cause the same effects that we saw in the chick experiment? These are all unknowns. But because we know they exist, and no virtually nothing else, we can infer that some of them perform functions that weren't identified in the passage. That allows us to choose D over E.

Hope this helps!