Reading comp PrepTest 156 · Section 3 · Question 26

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 primary purpose of 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.

Strategy Overview

Review the main point and any major Meta-Structures, then find an answer that best captures the latter with the details from the former

Answer Anticipation

A question that asks for a passage's "primary purpose" asks us to select the answer choice that describes why the author wrote the passage. The correct answer will describe an action: what the author hoped to do in the passage and how the author accomplished that. Now, in a broad sense, every author hopes to convince us that the main point is true. However, different authors employ different means to convince us of that main point. That's why the passage's Meta-Structure can be revealing: it helps us predetermine how this specific author was attempting to convey the main point. In this case, the central Meta-Structure was Problem/Solution. We'll use Problem/Solution as a starting point and fill in some details from our anticipated 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"). So, the author's primary purpose was to discuss one environmentally friendly alternative to a frequently used chemical. Let's look for something similar to that in the answer choices.

Answer choices

  1. A
    describe and analyze one Remaining source text redacted.
    Why choice A matches the stem

    Does this say the author's primary purpose is to discuss one environmentally friendly alternative to a frequently used chemical?

    Yes! This gets very close to our anticipation. The author both describes (in the first three paragraphs) and analyzes (in the last paragraph) Koskan's attempt to develop and market polyaspartate, which is a new, promising alternative to an existing product (polyacrylate). This answer choice matches our anticipation and doesn't mischaracterize any facts from the passage, so we can justifiably select and advance to the following question.

  2. B
    demonstrate the mistakes made Remaining source text redacted.
    Why choice B is not credited

    Does this say the author's primary purpose is to discuss one environmentally friendly alternative to a frequently used chemical?

    Not quite. Although the author discusses "one attempt to develop and market a new, promising alternative to an existing product," it's not entirely accurate to say the passage's primary purpose is to "demonstrate the mistakes made" in that attempt. A quick scan of our notes won't reveal any "mistakes" that Koskan made as he developed uses for polyaspartate. There were barriers to polyaspartate's widespread use, but those aren't Koskan's fault. Therefore, we can cross off (B).

  3. C
    illustrate the kinds of Remaining source text redacted.
    Why choice C is not credited

    Does this say the author's primary purpose is to discuss one environmentally friendly alternative to a frequently used chemical?

    No. The verb "illustrate" doesn't work for this passage. That verb suggests this is a Generalization/Example passage, where Koskan's problems are just one example of a bigger trend or movement. The author neither frames Koskan as an example nor discusses broader problems encountered in "attempts to market a new, promising alternative to an existing product." So, we can eliminate (C).

  4. D
    comment on the state Remaining source text redacted.
    Why choice D is not credited

    Does this say the author's primary purpose is to discuss one environmentally friendly alternative to a frequently used chemical?

    Nope. This makes it seem like the passage focused on the chemical industry, not the new chemical product Koskan developed. While the author occasionally comments on the environmental chemical industry (P4, S1; P4, S7), offering this commentary is not the author's primary focus. Therefore, we can cross (D) off.

  5. E
    explain the chemical processes Remaining source text redacted.
    Why choice E is not credited

    Does this say the author's primary purpose is to discuss one environmentally friendly alternative to a frequently used chemical?

    Not quite, as this answer choice makes the passage sound like a Phenomenon/Explanation passage. Although the author discusses "a particular new product" that is "a promising alternative to an existing product," the author doesn't spend much time explaining "the chemical processes" of that product. The author limits this discussion to a few sentences in the second paragraph (P2, S3-5). So, this answer choice does not describe the passage's primary purpose.

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A Credited 58%
  2. B 6%
  3. C 14%
  4. D 12%
  5. E 10%

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