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

Which one of the Remaining source text redacted.
Why the credited answer is right

Credited answer: A

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

Question Type

Science

Answer choices

  1. A
    At least some of Remaining source text redacted.
    Why choice A matches the stem
    Question Type:
    Minor Point/Must Be True

    Strategy Overview:
    Refer to notes or what you highlighted/underline to locate where the passage discusses peptides that Belcher and Hu tested, and refer to the relevant part of the passage as needed to find that answer choice that must be true

    Answer Anticipation:
    For questions that ask us to infer, from a few details in the passage, an answer choice that must be true, quickly finding and reviewing those details is critical. That is why we make brief notes describing the role of each paragraph and highlight or underline definitions and the minor Meta-Structures — doing so helps us find the salient information efficiently and reliably. Once we review that part of the passage, we can look through the answer choices to see which one is best supported by what we reviewed. Since the question stem asks us to make an inference, 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.

    Here, the question asks about the peptides that Belcher and Hu tested. Where did those show up in the passage? Looking at our notes, we wrote down that the second paragraph was about, "Belcher and Hu's research (developed new peptides to bind to semiconductor materials)." So, we can review the second paragraph to form an anticipation. Reviewing that paragraph, we'll recall that they created a billion peptides, some of which bound to semiconductor materials in specific ways (P2, S5). We also can see those that bound to semiconductor crystals only bound to one crystal (and onto a particular "face" of the crystal) (P2, S6). Belcher and Hu also they "evolved" some to generate more that had these characteristics (P2, S7).

    Let's look for an answer choice that relates to one of these details.

    Answer Choice Explanation:
    Does this relate to any of the details we reviewed in the second paragraph?

    Absolutely. In stating that the researchers "developed" additional peptides, the passage suggests that these peptides didn't already exist. Therefore, the passage implies that this answer choice is true. Experienced test-takers may opt to select (A) and advance straight to the following question.

    Key Takeaway:
    Skimming over half a paragraph before answering a question isn't a waste of time Reading and re-reading answer choices without knowing what you're looking for is! Besides, we can make up time spent reviewing the second paragraph by selecting (A) and moving on without even worrying about (B) through (E)!
  2. B
    At least one of Remaining source text redacted.
    Why choice B is not credited
    Does this relate to any of the details we reviewed in the second paragraph?

    Nope. Based on our review, we know the peptides Belcher and Hu tested bound "exclusively" to one of the crystals. That's two crystals short of three!
  3. C
    At least some of Remaining source text redacted.
    Why choice C is not credited
    Does this relate to any of the details we reviewed in the second paragraph?

    No. The passage notes that Belcher and Hu tested whether the peptides bound with both silicon and gallium arsenide (in addition to indium phosphide).
  4. D
    At least one of Remaining source text redacted.
    Why choice D is not credited
    Does this relate to any of the details we reviewed in the second paragraph?

    Nope. In fact, the second paragraph suggests that Belcher and Hu were the first to discover the ability of peptides to bind to semiconductor materials since "no known" peptide had this ability when they set out.
  5. E
    Other researchers had previously Remaining source text redacted.
    Why choice E is not credited
    Does this relate to any of the details we reviewed in the second paragraph?

    Negative. Similar to (D), there were no known peptides that bound to these materials. While it's possible that others tested some of these peptides and didn't find any that worked (Hu/Belcher only found a few out of a billion, after all), there's no indication that this happened.

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