Reading comp PrepTest 138 · Section 1 · Question 12

Passage

Questions 8-14  .        The characteristic smell or taste of a plant, to  . insects as well as to humans, Remaining source text redacted.
Passage walkthrough
Passage Summary

Topic: Science


Paragraph 1

  • Paragraph note
    • Distinction between primary substances (required for plant growth) and secondary substances (give plants taste/smell)
  • Views, minor Meta-Structures, and the author's attitude
    • List of two different chemicals in plants, according to the author:
      • Primary substances: required for growth and functioning, found in all plants (third sentence)
      • Secondary substances: No known internal function, different in different plant families, give plants taste and smell (fourth through last sentences)
    • Examples of primary substances, according to the author:
      • Proteins, carbs, vitamins, hormones (third sentence)
    • Author's attitude: "depends" (first sentence); "required" (third sentence); "found in all plants" (third sentence); "diverse and multitudinous array of chemicals" (fourth sentence); "no known role" (fourth sentence); "Only a few" (fifth sentence); "give plants their distinctive tastes and smells" (last sentence)

Paragraph 2

  • Paragraph note
    • Insects' role in the diversity of secondary substances developed (some attract helpful insets, others defend against harmful insects)
  • Views, minor Meta-Structures, and the author's attitude
    • Cause-and-effect relationships, according to the author:
      • Mutations cause the emergence of secondary substances (second sentence)
      • Some secondary substances' ability to attract pollinating insects causes the secondary substances to survive via natural selection (fourth sentence)
      • Some secondary substances' biochemical defenses against harmful insects cause the secondary substances to survive via natural selection (sixth sentence)
      • Some secondary substances cause harm or death to insects (seventh sentence)
      • Some secondary substances cause insects to avoid feeding on the plant (last sentence)
    • Author's attitude: "appear to have played a major role" (first sentence); "undoubtedly" (second sentence); "must pass the muster of natural selection" (third sentence); "must increase" (third sentence)

Paragraph 3

  • Paragraph note
    • Progression of evolution after insects (insects evade defenses and become associated with few plants)
  • Views, minor Meta-Structures, and the author's attitude
    • Cause-and-effect relationship, according to the author:
      • Plants' defenses cause insects to either develop ways avoid defenses (second sentence)
      • These defenses cause insects to become associated with very few plants (fourth and last sentences)
    • Examples of ways insects avoid plants' defenses, according to the author:
      • Detoxification and storing toxins so the insects aren't harmed (third sentence)
    • Author's attitude: "there has been an evolutionary competition" (first sentence); "must" (second sentence); "fewer and fewer" (last sentence)

Main Point: While secondary substances in plants start out from random mutations, it's a back-and-forth evolutionary "battle" with insects that has resulted in a variety of secondary substances across species of plants.

Key Lines?

Paragraph 1, Sentences 4 (P1, S4) - Definition of "secondary substances"

P2, S3 - How secondary substances emerge

P2, S4 - How secondary substances survive

P2, S6 - How secondary substances survive

P3, S5 - Outcome of secondary substances

Meta-Structure?

Phenomenon/Explanation: This passage uses a Phenomenon/Explanation Meta-Structure.* The passage spends Paragraph 1 building up to the statement about diverse secondary substances, which give plants their taste and smell but don't help the plant function. That poses a question that needs explaining — if they don't help a plant function, then why do they exist? The passage answers that question/explains the phenomenon in the rest of the passage. Secondary substances exist because random mutations cause them to develop, and then an evolutionary competition with insects causes the beneficial ones (either because they hurt insects or attract pollinating insects) to proliferate.

When a passage falls into the Phenomenon/Explanation Meta-Structure, the author's explanation serves as the passage's main point. Here, the author provides a multi-faceted explanation, which is how we got to our main point above.

*You could also characterize this passage as a Question/Answer passage (Q: How do secondary structures emerge and survive in plants? A: Through natural selection and by attracting/defending insects).

Cause and Effect: The most prominent minor Meta-Structure is the cause-and-effect relationship, most prominently featured in the second paragraph. Make sure you understand these cause-and-effect relationships because we're bound to get a question or two about them — perhaps even a difficult Strengthen or Weaken question.

Last Thoughts?

This passage includes a lot of science, but we can simplify it to a few basic cause-and-effect relationships to help us understand what's going on. If you don't find memorizing a few basic facts too onerous, keeping these in mind can save you some fact-finding missions as you answer the questions:

  • Mutations cause secondary substances to first appear
  • Some secondary substances survive because they attract pollinating insects
  • Some secondary substances survive because they defend against harmful insects
  • Plants' evolutions and insects' adaptations cause insects to become associated with very few plants

Question prompt

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

Credited answer: B

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

Question Type

Science

Strategy Overview

Review the relevant part of the passage and notes, if necessary, to anticipate key features of the relationship between primary and secondary substances

Answer Anticipation

These Application/Analogous Situation questions closely resemble Parallel Reasoning questions in Logical Reasoning. We want to find the answer choice that is structurally similar to the element we're asked to analogize. The correct answer won't have the same subject matter as the passage; instead, it will feature similar characteristics or themes as the element from the passage. Therefore, we should start by reviewing the key features of the element we're asked to parallel.In this case, we're asked to parallel the relationship between primary and secondary substances. Our notes reveal that the passage distinguishes the two in the first paragraph. There, the author says that these are the two categories of chemicals in plants (P1, S2) and that:Primary substances are "required for growth and proper functioning" and are found "in all plants" (P1, S3).Secondary substances are "diverse and multitudinous" and have "no known role" in internal plant functioning, but they do provide plants with their characteristic taste and smell (P1, S4-S6). So we need an answer with something analogous to plants, with two categories of something analogous to chemicals. These two categories have to cover all examples, and one has to be in everything and necessary to function, while the other has to be diverse and varied among different things and not necessary to internal function but still important in some other way. This anticipation may sound rather broad, but we want our anticipation to be very general for these questions. This will help us assess the elements or themes of the answer choices independent of their subject matter.Let's see if we can find an answer matching those criteria!

Answer choices

  1. A
    Electrical power for the Remaining source text redacted.
    Why choice A is not credited

    (A) Does this answer choice present two categories, one of which is functionally necessary and the other varied and not functionally necessary but important in some other way?

    No. Here, the electrical power is necessary for proper functioning, so it's analogous to primary substances. However, this answer choice discusses two sources of electrical power. If this were the correct answer, there'd be another type of power that isn't necessary for a hospital to function.

  2. B
    Mechanical components such as Remaining source text redacted.
    Why choice B matches the stem

    (B) Does this answer choice present two categories, one of which is functionally necessary and the other varied and not functionally necessary but important in some other way?

    Yes! Mechanical components are necessary for a car to run, so they're analogous to primary substances. Paint and taillights here aren't necessary for the car to run, so they're analogous to secondary substances. And just as secondary substances give a plant its characteristic taste and smell, which are related to other functions of plants, these other components of cars serve other functions that aren't related to the car running. As such, this answer provides an analog for both types of substances, making it the correct answer.

    Most test-takers prefer to read all the answer choices on an Analogous Situation question before making their selection. This answer choice is so close to our anticipation that we'd be justified in selecting it and advancing to the following question. At the very least, we should mark it as the probably correct answer and give the remaining choices an, at most, cursory reading.

  3. C
    Mechanical components such as Remaining source text redacted.
    Why choice C is not credited

    (C) Does this answer choice present two categories, one of which is functionally necessary and the other varied and not functionally necessary but important in some other way?

    No. The mechanical components here are necessary for a factory to run, so they're analogous to primary substances. Electrical components here directly feed into the mechanical components, whereas the secondary substances in plants aren't shown to have any function that feeds into primary substances. As such, the relationship between the components here is more direct than the relationship between primary and secondary substances in the passage, making this answer incorrect.

  4. D
    Some type of braking Remaining source text redacted.
    Why choice D is not credited

    (D) Does this answer choice present two categories, one of which is functionally necessary and the other varied and not functionally necessary but important in some other way?

    No. A braking system is established as being necessary to a functioning train, so it's analogous to a plant's primary substances. This answer then goes into two types of components in these systems, each of which is necessary for it to function. So, there's no analog to the secondary substances, making (D) incorrect.

  5. E
    Specially designed word processing Remaining source text redacted.
    Why choice E is not credited

    (E) Does this answer choice present two categories, one of which is functionally necessary and the other varied and not functionally necessary but important in some other way?

    No. This answer gets close to presenting an analog to primary substances, but even the word processor here is necessary only for a computer to serve as a word processor - not to function. As such, we can rule this answer out right off the bat.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 3%
  2. B Credited 75%
  3. C 18%
  4. D 3%
  5. E 1%

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