Reading comp PrepTest 156 · Section 3 · Question 27

Passage

  Organic chemist Larry Koskan's inspiration arrived in the mid-1980s, when he read a report by marine biologists describing how oyster Remaining source text redacted.
Passage walkthrough
Passage Summary

Topic: Science


Paragraph 1

  • Paragraph note
    • Background on Koskan’s inspiration (discovery that oysters produce protein-based agents)

Paragraph 2

  • Paragraph note
    • Comparison of polyacrylates (used to decrease scale on water-treatment equipment) and oyster's polyaspartate (can also decrease scale, but is biodegradable)
  • Views, minor Meta-Structures, and the author’s attitude
    • Cause-and-effect relationships, according to the author:
      • Polyacrylate causes a decrease in damaging mineral-scale deposits on surfaces of water-treatment equipment (second sentence)
      • Polyaspartate causes a decrease in the formation of calcium carbonate, which causes a decrease in damaging mineral-scale deposits on surfaces of water-treatment equipment (third sentence)
    • Comparisons, according to the author:
      • Polyacrylate and polyaspartate have a similar chemical structure (fourth sentence)
      • Unlike polyacrylate, polyaspartate is made up of peptides, so it is biodegradable (last sentence)

Paragraph 3

  • Paragraph note
    • Problem with polyacrylates (prevalent in detergents and diapers but last forever in landfills)
  • Views, minor Meta-Structures, and the author’s attitude
    • Author's view:
      • Polyacrylates are inexpensive and versatile, so they are used extensively in laundry detergents and baby diapers, even though they last virtually forever in landfills (first through last sentences)
    • Author's attitude: "inexpensive and versatile" (first sentence); "ideal" (fourth sentence); "trouble" (last sentence); "last virtually forever" (last sentence); "vast quantities" (last sentence)

Paragraph 4

  • Paragraph note
    • Author on the industry's waning interest in polyaspartate (too expensive) and the success of Koskan's company (successful at eliminating scale in offshore oil equipment and keeping fertilizer in soil)
  • Views, minor Meta-Structures, and the author’s attitude
    • Comparison, according to the author:
      • While the consumer products and chemical industry's early enthusiasm for polyaspartate eventually waned as it proved too expensive, Koskan's company believed that polyaspartate could work in specialized applications (second through fifth sentences)
    • Author's view:
      • Polyaspartate has shown unmatched success at eliminating scale in offshore oil equipment and reducing groundwater pollution, and Koskan's company's continued success would revitalize an environmental chemical industry with a reputation for ineffectiveness and high cost (sixth and last sentences)
    • Author's attitude: "growing rapidly" (first sentence); "Unfortunately" (third sentence); "unparalleled success" (sixth sentence); "may yet help enliven an environmental chemistry sector saddled with a reputation for ineffectiveness and high cost" (last sentence)

Main Point: Although using polyaspartate as a more environmentally friendly alternative to polyacrylate has proven too expensive for many companies, Koskan's use of polyaspartate in specialized applications has shown tremendous success.

Meta-Structure?

Problem/Solution: This passage best fits the Problem/Solution Meta-Structure*. In such a passage, the author will describe an issue and one or more potential solutions. In this particular passage, the author presents the problem with the extensive use of polyacrylates. While they are cheap and versatile (and less environmentally damaging than some products), they pretty much last forever in landfills. The author presents polyaspartate as a possible solution — this chemical functions similarly to polyacrylates, but they're biodegradable and thus more environmentally friendly.

In a Problem/Solution passage, the main point is generally the author’s opinion on the solution. The author doesn't summarize their opinion in one or two sentences, so we had to compose our own summary: "Although using polyaspartate as a more environmentally friendly alternative to polyacrylate has proven too expensive for many companies, Koskan's use of polyaspartate in specialized applications has shown tremendous success."

*That said, a few other Meta-Structures could work for this passage. You could certainly call this an Innovative [Subject] or Importance of [Subject] passage, framing Koskan as the innovative/important figure. If you classified this passage as either of these Meta-Structures, you'd probably come to a similar understanding of the passage's main point and organization.

Comparison: The author compares and contrasts polyacrylate and polyaspartate several times in this passage, making the comparison the most prominent minor Meta-Structure. Expect a question or two about these. To avoid some fact-finding missions and save some time, you can commit a few similarities and differences to memory if this isn't too onerous:

  • Similarities: Similar chemical structure, both decrease scale
  • Differences: Polyaspartate is made up of peptides and not hydrocarbon, polyaspartate is biodegradable, polyacrylate is cheap

Last Thoughts?

The words "polyacrylate" and "polyaspartate" are long, very similar, and there's a good chance you're unfamiliar with both. We're going to have a bad time if we mix them up. So, let's devise a strategy to make sure we know which is which. Personally, we're just going to scan the end of the word to see if it ends with "-late" or "-tate." The one that ends with "-late" has been used to control scale and put in products like laundry detergent and baby diapers. It's also the one that Koskan wants to say "late(r)" to, replacing it with the more modern "-tate." The "-tate" one is also biodegradable ... like a po-tate-o? Whatever the mnemonic device you come up with, the questions will be much easier if we can remember which one is "polyacrylate" and which is "polyaspartate."

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.

Strategy Overview

Remind ourselves of the main point of the passage, then head to the answers, focusing on those that line up with the main point and then using our notes/the passage to find the correct answer

Answer Anticipation

This question asks us to infer, based on the entire passage, a statement that must be true about both polyaspartate and polyacrylates. The entire passage discusses these two chemicals, so this question provides 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 rereading 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 choices

  1. A
    They perform identically within Remaining source text redacted.
    Why choice A is not credited

    Is this consistent with the main point and reflected in our notes on polyaspartate and polyacrylates?

    No. Our note for the second paragraph says that polyacrylates can "decrease scale on water-treatment equipment," polyaspartate "can also decrease scale, but is biodegradable." Since polyaspartate is biodegradable, it probably doesn't perform identically to polyacrylates in industrial applications. For one, we'd probably have to remove polyacrylates after applications, while we wouldn't have to remove polyaspartate. Moreover, this answer choice uses bold, SCOTUS-y language ("identically," "any") that is hard to support and thus unlikely to appear in the correct answer to a Must Be True question. For these reasons, we can eliminate — or at least table — (A) and move on to the next answer choice.

    If we had to review the passage to cross off (A), we'd see that the author claims that polyaspartate has "shown unparalleled success at eliminating scale in offshore oil production equipment" (P4, S6). If polyaspartate's capacity to remove scale is "unparalleled," it performs better than polyacrylates in this industrial application. This proves that (A) is false.

  2. B
    They were both discovered Remaining source text redacted.
    Why choice B is not credited

    Is this consistent with the main point and reflected in our notes on polyaspartate and polyacrylates?

    This isn't reflected in our notes. While our note for the first paragraph says that polyaspartate was discovered as a result of research into oysters, our notes don't say anything about the discovery of polyacrylates. Since this isn't reflected in our notes, we should resist any urge to check the passage, table (B), and check the next answer choice.

    If we had to review the passage to evaluate (B), we wouldn't find any support for the claim that polyacrylates were discovered as a result of research by marine biologists. The passage never discusses how polyacrylates were discovered, so (B) lacks textual support.

  3. C
    The chemical industry was Remaining source text redacted.
    Why choice C is not credited

    Is this consistent with the main point and reflected in our notes on polyaspartate and polyacrylates?

    Nope. In fact, our notes for the first and second paragraphs suggest that not much time had passed between biologists' "discovery" of polyaspartate in oysters and Koskan's realization that it can be used to "decrease scale." This suggests that (C) is false, at least as it pertains to polyaspartate. So, we can eliminate — or at least table — (C) and move on to the next question.

    If we had to review the passage to eliminate (C), we'd see that Koskan realized that polyaspartate could also control scale fairly soon after marine biologists discovered polyaspartate (P2, S3). Therefore, (C) is false.

  4. D
    They both have been Remaining source text redacted.
    Why choice D matches the stem

    Is this consistent with the main point and reflected in our notes on polyaspartate and polyacrylates?

    This isn't inconsistent with our notes. Our notes don't explicitly mention that polyaspartate and polyacrylates are used to reduce water pollution, but they don't rule this out either. If you don't remember that the passage discussed water pollution, you should resist any urge to check the passage, table (D), and check the next answer choice.

    After realizing the next answer choice isn't reflected in our notes either, we'll circle back to (D). Then, we can research the passage to see if polyaspartate and polyacrylates are both used to reduce water pollution. In the third paragraph, we learn that polyacrylates are employed as an "alternative to phosphates, which, via wastewater, pollute surface waters" (P3, S3). If polyacrylates replace a polluting additive, they are indeed used to reduce water pollution. In the fourth paragraph, the author says that polyaspartate is "used by the farming industry to keep chemical fertilizers in the soil longer, reducing pollution of groundwater" (P4, S6). This confirms that polyaspartate and polyacrylates both reduce water pollution, allowing us to select (D) and wrap up this passage.

  5. E
    At the time they Remaining source text redacted.
    Why choice E is not credited

    Is this consistent with the main point and reflected in our notes on polyaspartate and polyacrylates?

    Nope. In fact, our note for the last paragraph refers to chemical companies' "waning interest in polyaspartate." This suggests the companies' enthusiasm started high but then decreased. So, it doesn't sound like the companies were initially "skeptical" about polyaspartate's success. Moreover, our notes don't say anything about leading chemical companies' initial reactions to polyacrylates. For these reasons, we can eliminate — or at least table — (E) and return to any answer choice we haven't already eliminated.

    If we had to review the passage to eliminate (E), we'd see that the author says that "[s]oon" after Koskan brought polyaspartate to market, "leading chemical companies also began researching the issue" (P4, S2). This shows that leading chemical companies were not skeptical about polyaspartate's commercial success when it was first brought to the market. This proves that (E) is false.

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 29%
  2. B 12%
  3. C 11%
  4. D Credited 38%
  5. E 10%

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