Reading ComprehensionDifficulty: Easy

PT155 S3 P3 Q20 Explanation

Nanoscale Computer Chips

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsLocal PurposeScience

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Passage

This passage was adapted from an article published

Competition to make computer chips smaller and, consequently, faster and more efficient has driven a technological revolution, fueled economic growth, and rapidly made successive generations of computers obsolete. Yet at the current rate of progress this march toward miniaturization will hit a wall by about 2010—for many, an unthinkable prospect. The laws are investigating a different molecular pattern maker: peptides, amino acid chains that are shorter than proteins.

The project grew out of Belcher’s doctoral research on abalone. Her research group discovered in the mid-1990s that a specific peptide causes calcium carbonate to crystallize into the structure found only in the tough abalone shell. From that discovery, Belcher and Hu, Belcher’s postdoctoral adviser at the time, realized that if they resembling accelerated evolution, they developed additional related peptides from those that had the initially promising characteristics.

Hu says that in order to use such a method to assemble a set of circuit-building tools it would be necessary to identify many additional organic compounds that bind to circuit-component materials. The group is making progress on that quest. As they have expanded their targets to 20 more semiconductor materials, their glue. It will take that kind of finesse at the nanoscale to produce selfassembling circuits.

What this question is testing

Local Purpose

Anticipate

This is a Local Purpose question, so step back and ask: why are these specific sentences in the passage? What are they doing for the rest of the text?

The first sentence tells you that shrinking computer chips has been a huge deal for technology and the economy. The second sentence tells you that this whole process is about to slam into a wall — by about 2010 it just stops working with current methods. Together, these two sentences give you the stakes: a critical engine of progress is about to stall. That's exactly the problem Belcher and Hu's research is trying to solve, and the rest of the passage is about their approach.

Goal

Looking for an answer that captures the setup-the-stakes role. Common traps to watch for:

Answers that imply skepticism toward Belcher and Hu — none is mentioned

Answers that frame the sentences as an opposing view — they aren't a viewpoint, they're context

Answers that frame them as a testable hypothesis — they describe a fact (the wall) and stakes (why it matters), not a claim under investigation

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
20.

The primary role of the first two sentences of the passage is to help

Answer choices

  1. Out of Scope2% picked this

    why research of the sort done by Belcher and Hu was not previously undertaken

    The first two sentences explain why the research matters (miniaturization is critical and is about to hit a wall), not why other researchers haven't done it. The passage actually says other researchers are working on this — most of them on DNA — and the passage never explains why peptide work specifically wasn't pursued earlier.

  2. Correct86% picked this

    the purpose and importance of the research that Belcher and Hu

    Why this is right

    The first sentence establishes the importance of miniaturization (it has driven technology and economic growth); the second sentence establishes the urgency (the march is about to stop). Together they set up the purpose of the research that follows: to find a way past the 25-nm wall. The rest of P1 immediately introduces Belcher and Hu's peptide approach as a candidate. (B) names exactly this setup function — purpose and importance.

    Skill tested: Local Purpose · how this choice captures the passage's function is the move to repeat next time.

  3. Unsupported2% picked this

    the skepticism with which some members of the scientific community have greeted Belcher

    The passage never mentions skepticism toward Belcher and Hu's research, and the first two sentences certainly don't express any. They're neutral context about miniaturization and the coming limit. (C) reads a doubt into the passage that isn't there.

  4. Wrong View6% picked this

    a commonly held viewpoint against which Belcher and Hu’s research

    The first two sentences don't set up an opposing viewpoint that Belcher and Hu's research is directed against. They describe a factual situation — miniaturization's importance and its coming limit. The research isn't opposing a "view"; it's addressing a physics-imposed problem.

  5. Wrong Purpose3% picked this

    a hypothesis that Belcher and Hu’s research is designed

    The first two sentences don't state a hypothesis. They state two facts: miniaturization has driven a revolution, and the current path is about to end. Belcher and Hu's research isn't designed to test whether either of these is true; it's designed to respond to the wall by finding another route to small-scale electronics.

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