Reading comp PrepTest 145 · Section 1 · Question 25
Passage
. The French biologist Jean-Baptiste de Lamarck . (1744–1829) outlined a theory of evolutionary change . in 1809, 50 years
Remaining source text redacted.
Passage walkthrough
Passage SummaryTopic: Science
Paragraph 1
While biologists remain skeptical, Steele and others have proposed a Lamarckian means by which learned immunity could be passed down to the next generation.
Key Lines:
Lines 12-16 - The hypothesis to be explored is introduced
Lines 17-21 - Questions are presented (relevant to Steele's hypothesis)
Lines 24-29 - An answer is presented
Lines 34-38 - Another question is asked (directly related to Steele's hypothesis)
Lines 41-43 - Steele's answers presented
Lines 44-45 - Another question is asked (about Steele's hypothesis)
Lines 48-51 - Steele's answer/evidence is noted
Lines 55-58 - Skepticism towards Steele is noted
Meta-Structure:
Question/Answer - This passage has a Question/Answer structure, but it's a little different than other passages with that structure. Instead of having a central question that the passage attempts to answer, this one walks through a series of questions, each which has at least one answer presented to it. As such, we can't rely on the questions and answers to define the main point—we need to infer that main point by bringing all the questions together.
Old Theory/New Theory - Much like this passage doesn't have a traditional Question/Answer structure, it doesn't have a traditional Old Theory/New Theory structure. Normally, there would be an old theory that's being supplanted by a new one, and the Author's thoughts on the new theory define the main point. Here, there's an old theory (Lamarckism) that's replaced by a new one (Darwinism), but then some scientists try to revive the old theory (at least with respect to a certain area—immune systems), but there's still a debate over it.
Last Thoughts:
This is a tough passage in that it brings up genes, DNA, and RNA. But remember—you don't need to know any science for the LSAT! Any science they want you to know, they've written into the passage. So focus on the Question/Answer structure, and the viewpoints, and you'll be fine!
Also, note that the Author doesn't take sides in this debate! She presents Steele's view/evidence, and she presents the skeptical biologists who aren't swayed by Steele's argument, but she never gives any indication as to which side she thinks is more persuasive.
Paragraph 1
- Paragraph note
- A theory is outlined, ridiculed, and potentially redeemed
- Views, minor Meta-Structures, and the author's attitude
- Lamarck - Pre-Darwin, said animals adapt to environment and pass on
- Biologists - That's ridiculous
- Steele - Lamarckism happens in the immune system
- Paragraph note
- A question is posed and answered
- Views, minor Meta-Structures, and the author's attitude
- Question - How does the immune system adapt to so many and new diseases?
- Answer - One type of cell's RNA mutates a lot and gets tested against new diseases until one works
- Paragraph note
- Process/Question - How can this RNA then become DNA and get passed on?
- Views, minor Meta-Structures, and the author's attitude
- Process - Reverse transcription - RNA alters DNA to have disease fighting ability
- Question - How does this get passed on?
- Answer (Steele) - Viruses carry DNA to reproductive cells to pass on (theoretical, but based on known processes)
- Paragraph note
- A question is asked, evidence is presented, and a disagreement is noted
- Views, minor Meta-Structures, and the author's attitude
- Question - Does Steele's process actually happen?
- Author - Can "never" observe directly; must use circumstantial evidence
- Steele - Yes, and we have evidence in genes
- Other biologists - Probably not, there are less radical explanations
While biologists remain skeptical, Steele and others have proposed a Lamarckian means by which learned immunity could be passed down to the next generation.
Key Lines:
Lines 12-16 - The hypothesis to be explored is introduced
Lines 17-21 - Questions are presented (relevant to Steele's hypothesis)
Lines 24-29 - An answer is presented
Lines 34-38 - Another question is asked (directly related to Steele's hypothesis)
Lines 41-43 - Steele's answers presented
Lines 44-45 - Another question is asked (about Steele's hypothesis)
Lines 48-51 - Steele's answer/evidence is noted
Lines 55-58 - Skepticism towards Steele is noted
Meta-Structure:
Question/Answer - This passage has a Question/Answer structure, but it's a little different than other passages with that structure. Instead of having a central question that the passage attempts to answer, this one walks through a series of questions, each which has at least one answer presented to it. As such, we can't rely on the questions and answers to define the main point—we need to infer that main point by bringing all the questions together.
Old Theory/New Theory - Much like this passage doesn't have a traditional Question/Answer structure, it doesn't have a traditional Old Theory/New Theory structure. Normally, there would be an old theory that's being supplanted by a new one, and the Author's thoughts on the new theory define the main point. Here, there's an old theory (Lamarckism) that's replaced by a new one (Darwinism), but then some scientists try to revive the old theory (at least with respect to a certain area—immune systems), but there's still a debate over it.
Last Thoughts:
This is a tough passage in that it brings up genes, DNA, and RNA. But remember—you don't need to know any science for the LSAT! Any science they want you to know, they've written into the passage. So focus on the Question/Answer structure, and the viewpoints, and you'll be fine!
Also, note that the Author doesn't take sides in this debate! She presents Steele's view/evidence, and she presents the skeptical biologists who aren't swayed by Steele's argument, but she never gives any indication as to which side she thinks is more persuasive.
Question prompt
The passage most strongly
Remaining source text redacted.
Why the credited answer is right
Credited answer: B
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
-
AContrary to the opinion Remaining source text redacted.
Why choice A is not credited
Incorrect. (Line 38; Line 41; Line 48; Line 51; Lines 55-58) Whenever the Author discusses Steele's hypothesis, she talks about what he and his adherents "believe" or "claim." She also brings up those who are skeptical of his claims. She never takes Steele's side, even seeming a bit skeptical at times ("does it ever actually occur?"), so this answer is incorrect. -
BSteele and his colleagues Remaining source text redacted.
Why choice B matches the stem
Correct. Question Type:
Must Be True
Strategy Overview:
Review the main point, then head straight to the answers
Answer Anticipation/Relevant Lines:
Since this question presents no information as to the topic or section of the passage where the answer will come from, we should remind ourselves of the main point so we can focus on answers that align with that. We said it was:
While biologists remain skeptical, Steele and others have proposed a Lamarckian means by which learned immunity could be passed down to the next generation.
We should also note that the Author was more neutral in this passage than normal, not 100% sold on Steele's theory, so we should keep that in mind.
Answer Explanation:
(Lines 30-33) Reverse transcription was mentioned at the beginning of Paragraph 3. There, it's noted that Steele "hypothesizes" that this happens in the immune system, and that the process has been witnessed "in other contexts." If Steele had witnessed it in this context, it wouldn't still be a hypothesis, so this answer is supported by the language in the passage.
Key Takeaway:
There are two things we can learn about what's important to note in an RC passage by looking at these answers, as they ask about and are wrong for two primary reasons. First, the question itself ends up being about evidence—whether or not Steele has evidence that he directly observed of the phenomenon he cites. Second, many of the wrong answers are strong, or they reference strong language in the passage.
So the takeaways? Always note evidence. Always note strong language. -
CThe patterns of mutations Remaining source text redacted.
Why choice C is not credited
Incorrect. (Lines 48-55; Lines 41-42) Viruses altering DNA is the mechanism that Steele proposes for his theory, but the Author isn't sold on it, so she wouldn't agree that the patterns noted by Steele as evidence "indicate" that his theory is correct. -
DThe passing on of Remaining source text redacted.
Why choice D is not credited
Incorrect. (Lines 14-16) While Steele's theory is about the immune system, there's no language in the passage that limits the scope of the discussion to the immune system. The Author does seem skeptical of Steele's claims, but she may believe that it's possible there are other places where Lamarckian evolution occurs. -
EUnless a hypothesis can Remaining source text redacted.
Why choice E is not credited
Incorrect. (Lines 46-47) When discussing evolutionary mechanisms, the Author notes that they are "never observed directly" (which we noted because of the extreme language), and that we "must" (same note) rely on circumstantial evidence. She's skeptical of Steele's theory, but she's clearly not skeptical of evolutionary theory overall, so she accepts evolutionary theories that lack direct observation—contradicting this answer.
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Discussion
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Why would C be incorrect? 1 reply
Started by @MichaelaJ
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E 3 replies
Started by tomgbean