PrepTest 155

[lcid:3718] Prep Test 155 LSAT — Reading Comp — S3 Reading comp

Passage

This passage was adapted from an article published in 2000.   Competition to make computer chips smaller and, consequently, faster Remaining source text redacted.
Passage walkthrough
Passage Summary Topic:
Science

Paragraph 1
  • Paragraph note
    • Problem (making computer chips smaller) and one possible solution (using peptides)
  • Views, minor Meta-Structures, and the author's attitude
    • Definition of "transistor": electronic devices that make up computer chips (third sentence)
    • Definition of "peptide": amino acid that makes molecular patterns (last sentence)
    • Cause-and-effect relationships:
      • Competition to make computer chips smaller has caused technologies to advance and economies to grow (first sentence)
    • Comparisons:
      • With current methods, transistors cannot be smaller than 25 nanometers, but living cells can make complex structures smaller (fourth setnece)
      • Most research into making computer chips smaller involves using DNA to assemble smaller computer chips, but Hu/Belcher attempt to use peptides/amino acids (last sentence)
    • Author's attitude: "revolution" (first sentence); "may be hope" (fourth sentence)
Paragraph 2
  • Paragraph note
    • Belcher and Hu's research (developed new peptides to bind to semiconductor materials)
  • Views, minor Meta-Structures, and the author's attitude
    • Cause-and-effect relationship:
      • A specific peptide causes calcium carbonate to turn into the structure found on abalone shells (second sentence)
    • Comparisons:
      • If a peptide can grow calcium carbonate into an abalone shell, a similar peptide could direct the growth of semiconductor materials to transistors (third sentence)
      • To find more peptides that could attach to semiconductor materials, Belcher and Hu used a process similar to accelerated evolution (last sentence)
    • List of semiconductor materials:
      • silicon, gallium arsenide, indium phosphide crystals (fifth sentence)
    • Author's attitude: "not only ... but also" (sixth sentence); "initially promising" (last sentence)
Paragraph 3
  • Paragraph note
    • Belcher and Hu's remaining goals (find more peptides that bind) and progress (promising)
  • Views, minor Meta-Structures, and the author's attitude
    • Author's view:
      • Belcher and Hu are making promising advancements in finding order to use peptides to bind to semiconductor materials (second through last sentence)
    • Comparison:
      • New peptides that can bind two different crystals function similarly to a glue (fourth sentence)
    • Author's attitude: "making progress" (second sentence); "ballooned into the hundreds" (third sentence); "will take that kind of finesse" (last sentence)


Main Point:
Hu and Belcher's promising research into using peptides to bind to computer-chip materials might allow scientists to work around the current theoretical minimum size of computer chips.

Key Lines?
Paragraph 1, Sentence 2 (P1, S2) - Problem introduced
P2, S3 - Possible solution
P3, S2-4 - Author's evaluation of the solution

Meta-Structure?
Problem/Solution: This passage best fits the Problem/Solution Meta-Structure*. The author describes a problem contemporary — well, actually, 2000s-era — technologists face: how to make computer chips smaller than the laws of physics will allow. The rest of the passage focuses on one potential solution: Belcher and Hu's use of organic compounds known as peptides to bind together computer chip materials.

In a Problem/Solution passage, the author's opinion of the proposed solution is the passage's main point. The author provides their opinion in the last paragraph. The author notes that Belcher and Hu haven't cracked the code yet, but they're making promising advancements. So, we've summarized the main point as, "Hu and Belcher's promising research into using peptides to bind to computer-chip materials might allow scientists to work around the current theoretical minimum size of computer chips."

*Some may see this as an Innovative Subject passage, since Belcher and Hu utilize such a unique approach. If this understanding of the passage makes more sense to you, that's a-OK! The Meta-Structures are here to help us think about a passage's overarching structure and ideas. We don't have to agree on which Meta-Structure a passage has to realize the benefits of the Meta-Structures.

Last Thoughts?
It's important to note, from the last paragraph, that Hu and Belcher haven't solved the problem yet — they're still working on it! The first line of the last paragraph lets us know that they haven't yet been able to assemble a circuit using peptides.

Question prompt

The passage most strongly Remaining source text redacted.
Why the credited answer is right

Credited answer: D

The notes below walk through why it fits the stem and how to eliminate the rest.

Question Type

Science

Answer choices

  1. A
    Some peptides that bind Remaining source text redacted.
    Why choice A is not credited
    Is this reflected in the passage's main point or any of our notes?

    This isn't unrelated to the main point, and our note for the second paragraph indicates that "new peptides to bind to semiconductor materials." However, this is an awfully specific answer choice. We could research whether this is supported by checking the second paragraph. But it may be more efficient to check the remaining answer choices to see if there are any that are more related to the main point or better represented in our notes.

    If we did review the passage to see if (A) is supported, we'd find that the passage notes that the researchers discovered some peptides that bind "exclusively" to one of the crystals (P2, S6). So this answer is, if anything, contradicted by the passage. And while they've designed new peptides that "bind to two different crystals at once" (P3, S4), there's no indication that these pairs of crystals include gallium arsenide and indium phosphide.
  2. B
    Researchers besides Belcher and Remaining source text redacted.
    Why choice B is not credited
    Is this reflected in the passage's main point or any of our notes?

    Nope. Neither our main point nor our notes mention other researchers who are looking into peptides. Therefore, we can table this answer choice and keep looking.

    If we needed to review the passage to check whether (B) is supported, we'd see that the passage suggests that other researchers are looking at DNA (P1, S5), not peptides.
  3. C
    Neither Belcher nor Hu Remaining source text redacted.
    Why choice C is not credited
    Is this reflected in the passage's main point or any of our notes?

    No. We don't have any information about Belcher or Hu's prior research in either the main point or our passage notes, so we can table or eliminate this answer choice and check the next one. Besides, we wouldn't find any support for this answer if we re-read the entire passage.
  4. D
    Silicon, gallium arsenide, and Remaining source text redacted.
    Why choice D matches the stem
    Question Type:
    Minor Point/Must Be True

    Strategy Overview:
    Reiterate the main point of the passage, find answers that align with that, and then check back in the passage to confirm any details as needed

    Answer Anticipation:
    This question asks us to infer, based on the entire passage, a statement that must be true. Such questions can be very challenging. These questions provide little indication as to the topic of the correct answer or where it'll show up in the passage. Moreover, the correct answer probably won't restate something from the passage. Instead, the question will likely require us to draw a connection between a few different pieces of information.

    We'll need to rely on our big-picture understanding of the passage to answer these questions. We should start by reminding ourselves of the main point (either by reviewing what we said after reading the passage or by re-reading our answer to the main point question). From there, we can head to the answer choices. If something in an answer choice doesn't seem familiar and isn't reflected in our notes on each paragraph, we shouldn't check the passage to see if it was mentioned. Instead, we'll table it and move on to the next answer choice. If something seems inconsistent with the main point, we can eliminate it. If something seems familiar, consistent with the main point, or reflected in our notes, we'll use our notes/highlights/underlines to find the part of the passage that proves the answer choice must be true. If we can find that confirmation, we'll select that answer choice and move on.

    Answer Choice Explanation:
    Is this reflected in the passage's main point or any of our notes?

    Yes! This answer lines up with the overall argument in the passage — that peptides are a promising solution to creating smaller computer chips. And our note for the final paragraph is "Belcher and Hu's remaining goals (find more peptides that bind) and progress (promising)." If Belcher and Hu are making "promising" progress on their goal to find more peptides that bind to semiconductor materials, they may have identified more semiconductor materials that peptides can attach to.

    (This answer choice is also less specific than answer choice (A). So if you had eliminated all but (A) and (D) — as many test-takers do on this question — it would be wiser to search the passage for support for (D), as it's less specific wording makes it easier to support and thus more likely to be correct.)

    Reviewing the final paragraph, we'll see that Belcher and Hu have "ballooned" their list of peptides that work with semiconductor materials into the hundred when they "expanded" their targets to twenty other materials (P3, S3). This strongly supports the view that some of these other hundreds of peptides can bind to some of these other twenty materials. This confirms that (D) is correct.

    Key Takeaway:
    When you have nothing to go off of in RC, fall back on the overall viewpoint of the passage. The correct answer will likely be something that supports that view — especially when there's only a single viewpoint, as in this passage.
  5. E
    Peptides have been used Remaining source text redacted.
    Why choice E is not credited
    Is this reflected in the passage's main point or any of our notes?

    No. Neither the main point nor the notes discuss other industrial applications of peptides. We can cross this one off.

    Even if we did check the passage, we'd find that the passage didn't note any other use of peptides in an industrial application.

What this tests

Discussion

  • Why D? 3 replies

    Started by samlhoover

  • Why not B? 1 reply

    Started by RachP

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