Highlight the author’s conclusions:
p4:
prions are an entirely new class of infectious pathogens.
***
p1 is all background, but the author drops a huge hint about what the argument’s gonna be when they say “It was thus widely assumed…” Probably we’ll find out that assumption wasn’t so hot.
p2 brings in the “scientists” who disagree that all pathogens have DNA or RNA. Then there’s a lot of background about CJD, and where the research “led surprisingly”. It seems like support for the scientists’ disagreement, but the author hasn’t stated the connection yet, so I’m not highlighting any conclusions here.
p3 is a lot of very dense science info. I’m not worried about understanding any more than it takes to tell that it’s just support, pointing toward the author agreeing with the scientists from the last paragraph.
p4 finally brings in a clear author conclusion with “research has supported the conclusion that…” So I expect we all agree about the highlighting there.
Map the wording of the answers to the reference in the prompt, or to the author’s conclusions:
1. Which one of the following most accurately expresses the main point of the passage?
Map the answers to the author’s conclusions.
(A) …the mechanism by which…prions reproduce themselves is not yet known in detail.
Such a sucker bet. That’s just a detail from the end of the passage, but it doesn’t sound much like the author’s conclusion.
(B) …uncovered a deadly class of protein pathogens uniquely capable of…
This brings in a lot more detail than the author’s stated conclusion, but it all maps. Prions are the “protein pathogens”, being “uncovered” maps to “entirely new”, and “without genetic material” lines up with the busted assumption that all pathogens have that stuff.
(C) …prions may be responsible…for most other degenerative…
This doesn’t map to the conclusion well at all, and the person who wrote this answer went out of their way to scream “this is wrong!” by adding in “most”, which the author never said.
(D) The assertion that prions cause CJD has been received…
Another detail that doesn’t really sound like the conclusion we highlighted.
(E) …they are somehow capable of reproducing themselves.
Make that three accurate details that don’t map to the conclusion.
(B) is the correct answer.
2. Which one of the following is most strongly supported by the passage?
Map the answers to the author’s conclusions. It’s possible, but unlikely, that the right answer will rely on a small detail. So you should only be re-reading if you really have to, after you eliminate answers that don’t fit the conclusion.
(A) …required scientists to reconsider their traditional beliefs…
Well, yeah. If prions are “entirely new”, and we learned about them from the CJD research, then this all adds up. And “pathogens” are definitely “causes of infection”, so I think all of this is clearly baked into the conclusion.
(B) CJD is contagious…
This word isn’t in there. “Infectious” is not quite the same thing. There’s no other synonym for it in there. There’s no mention of passing CJD on to someone else. Get this answer out of here.
(C) …prevention of certain genetic abnormalities.
I’m not a scientist, but the one thing I took away from the argument is that prions don’t have genetic material. That’s the conclusion, they’re an “entirely new” thing without DNA or RNA. The “abnormalities” the passage talks about aren’t genetic, they’re protein-y.
(D) …the disease progresses at about the same rate in all patients…
This is too specific to fit the conclusion, but if you have to do a quick word search you’ll see the last sentence of the third paragraph says there are actually “wide variations”.
(E) The prion theory of infection has weak support…
This doesn’t align with the conclusion at all, and the last paragraph specifically explained how the support has been building.
(A) is the correct answer.
3. If the hypothesis tgat CJD is caused by prions is correct, finding the answer to which one of the following questions would tend most to help a physician in deciding whether a patient has CJD?
Map the answers to the reference in the prompt. You know that CJD is caused by prions, so the question in the right answer will be some version of “do they have prions?” The right answer probably won’t be that straight forward, but it will definitely map to part of the description of prions. All of that’s in the third paragraph.
(A) …blow to the skull recently?
(B) …bouts of insomnia?
(C) …genetic damage?
(D) …immediate family ever had brain disease?
None of these even come close to saying “prions”. And except for “insomnia”, none of this wording even shows up anywhere.
(E) …abnormal thread-like structures?
The author uses the word “abnormal” three times while describing how prions do their thing in the third paragraph. And they even used the exact phrase “thread-like structures” too.
(E) is the correct answer.
4. Which one of the following is most strongly supported by the passage?
Map the answers to the author’s conclusions.
(A) …through the injection of abnormally shaped prions…
There’s no mention of “injection” on transmission of prions from one person to another.
(B) Most infectious diseases…
Stop. There’s only one infectious disease talked about in detail in the passage, and a couple others mentioned in passing toward the end. But there’s no support for any statement about “most infectious diseases.”
(C) If they were unable to reproduce themselves…
The third paragraph says prions have “the ability reproduce themselves…initiating a chain reaction” that leads to CJD. So it’s totally reasonable to conclude that if they couldn’t reproduce, the chain reaction wouldn’t happen, and the person wouldn’t get CJD. I likes.
(D) Alzheimer’s disease and Parkinson’s disease are caused by…the same prion pathogen that causes CJD.
The passage only says “a similar process of protein malformation may be involved” in these other diseases. It’s not a fact for sure, and it’s not necessarily the “same” pathogen. This is way too strong.
(E) …more aggressively than diseases caused by other…
There’s no comparison between how prion diseases progress and how other diseases progress, so there’s no support for this at all.
(C) is the correct answer.
5. It can be inferred from the passage that the author would be least likely to agree with which one of the following?
Map the answers to the author’s conclusions, but make sure you’re clear we’re looking for an answer that disagrees with the author based on the wording of this prompt.
(A) …abnormally shaped prions in brain tissue is a sign of neurological disease.
This totally fits with the author’s explanation of prions, so I think it’s safe to say they’d agree with this.
(B) Some patients currently infected with CJD will recover…
Whoa, I don’t think so. The passage focused on how bad CJD is, and never talked about recovery. Even if you don’t find the spot where the passage says “CJD is inevitably fatal”, I’d expect you not to eliminate this one. Of course that reference proves this is the right answer.
(C) Prions do not require nucleic acid…
Yup, that’s the whole point here. There’s no DNA or RNA involved, just proteins. The author for sure agrees with this.
(D) The body has no natural defense against CJD.
This aligns with the overall message we got about CJD, so it should be safe to eliminate even if you don’t find the spot where the passage says “the body does not produce an immune response” to prions.
(E) Scientists have only a partial understanding…
This maps nicely to the last line of the passage that says how prions reproduce is “yet to be completely understood.”
(B) is the correct answer.
6. Given the manner in which the term “pathogen” is used in the passage, and assuming that the prion theory of infection is correct, which one of the following must be false?
Map the answers to the author’s conclusions. It’s possible this one relies on a specific reference, but it doesn’t tell us exactly to look. But “pathogen” is right there in the conclusion, so I’d expect the right answer to map to the conclusion pretty strongly.
(A) Nothing that lacks nucleic acid is a pathogen.
This is exactly the assumption from the first paragraph that the whole rest of the passage disagrees with. Prions are “entirely new” and don’t have nucleic acid. This must be false. I’d love to see you pick this and keep going without worrying about the rest of the list.
(B) Prions are a relatively newly discovered type of pathogen.
Sounds exactly like the conclusion, so no way this is false.
(C) All pathogens can cause infection.
Yup, that’s the definition of “pathogen”, so that’s not false.
(D) Pathogens contribute in some manner to the occurrence of CJD.
This is a more specific version of (C). Yes, pathogens cause diseases, including CJD.
(E) There are other pathogens besides…
Again, this maps pretty perfectly to the conclusion. It’s not false.
(A) is the correct answer.
7. Which one of the following, if ture, would most undermine the claim that prions cause CJD?
Map the answers to the author’s conclusions. The answers are wordy and detailed, but expect the right answer to come back to the big picture. Prions are protein, they don’t have genetic material, and they’re “entirely new.” The right answer will say CJD is caused by something that does NOT fit these characteristics.
(A) …symptoms closely resembling those of CJD…
Okay, but that’s not the same as saying the patient actually has CJD. Don’t be fooled, this doesn’t tell us anything about what causes CJD.
(B) None of the therapies currently available…
Stop. The question is about what causes CJD, not how to treat it. Info about “therapies” doesn’t help us.
(C) …linked prions to degenerative conditions not affecting the brain…
Cool story. But that doesn’t mean they don’t also cause CJD, so this is pretty much irrelevant.
(D) …failed to show any hereditary predisposition to CJD.
Did you read anything about CJD being “hereditary”? Me neither. This doesn’t impact the argument in the passage at all.
(E) …antibacterial drug…is proving to be effective in reversing the onset of CJD.
This is pretty tricky, but the test expects you to see that “antibacterial” tells us CJD is caused by bacteria. We’re finally mapping to the conclusion. Prions are supposed to be “entirely new”, and they’re not bacteria. So if treating CJD this way works, it makes the argument in the passage pretty sus.
(E) is the correct answer.
Elliot Hirsen / LSAT coach 
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