Reading comp PrepTest 154 · Section 3 · Question 15
Passage
For nearly a century after the discovery in the 1880s that a bacterium, Vibrio cholerae , causes cholera, scientists believed
Remaining source text redacted.
Passage walkthrough
Passage SummaryTopic: Science
Paragraph 1
There is evidence suggesting that Rita Colwell's hypothesis about "viable but nonculturable" cholera bacteria surviving in the ocean and in a sporelike state is correct, as it explains seemingly spontaneous outbreaks of the disease in areas where it has been eradicated.
Key Lines:
Lines 3-6 - Traditional scientific theory is discussed
Lines 9-11 - A question left open by this theory
Lines 12-14 - A new scientist/theory is introduced
Lines 21-24 - More on that theory
Lines 25-30 - The new theory is tested
Lines 40-42 - The new theory is expanded
Lines 49-51 - A question is posed for the new theory
Lines 51-54 - An answer is put forward
Meta-Structure:
Old Theory/New Theory - The old theory concerning the spread of cholera is shown to leave open a question that a new theory answers.
Question/Answer - Two questions are posed. The first (Lines 9-11) is broad and leads to the main point - Colwell's new theory. The second (Lines 49-50) is limited and leads to a hypothesis to be tested under Colwell's theory.
Last Thoughts:
Normally, the Author is a bit more on board with a new theory being presented. Here, there's a mix. She states that Colwell's studies "revealed" some things about V. cholerae (Line 40), but also poses Colwell's water theory as being something that isn't 100% certain ("If, as Colwell believes" in Line 54).
So we need to be careful in selecting answers that don't overshoot the Author's feelings towards Colwell's theory and pick an answer that reflects a certainty that doesn't exist.
Also, note that we split Paragraph 2 up. It was pretty long, and there was a natural breaking point between where Colwell raised her claim and people expressed skepticism, and the specific situation that allowed her to discover evidence for her hypothesis.
Paragraph 1
- Paragraph note
- A common scientific belief is discussed, and a question it leaves open is raised
- Views, minor Meta-Structures, and the author's attitude
- Common belief - Cholera travels via human hosts (waste into food and water supplies)
- Question - How do spontaneous outbreaks in areas cholera was eliminated happen?
- Paragraph note
- A new belief is brought up and skepticism is discussed
- Views, minor Meta-Structures, and the author's attitude
- Rita Colwell (1970s) - Claimed to have found cholera in seawater and it can go undetected by common culture tests
- Skepticism - "No" biologist thought it could live outside of humans, and there were no outbreaks since 1911
- Paragraph note
- Colwell's hypothesis is put to the test
- Views, minor Meta-Structures, and the author's attitude
- Colwell used a new test (antibodies/UV) and found cholera bacteria in bayous that traditional tests missed
- Paragraph note
- Further studies backing up/expanding on Colwell's hypothesis, and a future course of inquiry
- Views, minor Meta-Structures, and the author's attitude
- Tests show bacteria go into sporelike state that can't be detected using traditional tests
- That state is more survivable
- Question - What gets them out of sporelike state? Potential answer - Sea-surface temp spikes (e.g., Bay of Bengal)
There is evidence suggesting that Rita Colwell's hypothesis about "viable but nonculturable" cholera bacteria surviving in the ocean and in a sporelike state is correct, as it explains seemingly spontaneous outbreaks of the disease in areas where it has been eradicated.
Key Lines:
Lines 3-6 - Traditional scientific theory is discussed
Lines 9-11 - A question left open by this theory
Lines 12-14 - A new scientist/theory is introduced
Lines 21-24 - More on that theory
Lines 25-30 - The new theory is tested
Lines 40-42 - The new theory is expanded
Lines 49-51 - A question is posed for the new theory
Lines 51-54 - An answer is put forward
Meta-Structure:
Old Theory/New Theory - The old theory concerning the spread of cholera is shown to leave open a question that a new theory answers.
Question/Answer - Two questions are posed. The first (Lines 9-11) is broad and leads to the main point - Colwell's new theory. The second (Lines 49-50) is limited and leads to a hypothesis to be tested under Colwell's theory.
Last Thoughts:
Normally, the Author is a bit more on board with a new theory being presented. Here, there's a mix. She states that Colwell's studies "revealed" some things about V. cholerae (Line 40), but also poses Colwell's water theory as being something that isn't 100% certain ("If, as Colwell believes" in Line 54).
So we need to be careful in selecting answers that don't overshoot the Author's feelings towards Colwell's theory and pick an answer that reflects a certainty that doesn't exist.
Also, note that we split Paragraph 2 up. It was pretty long, and there was a natural breaking point between where Colwell raised her claim and people expressed skepticism, and the specific situation that allowed her to discover evidence for her hypothesis.
Question prompt
The passage suggests that
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
Answer choices
-
AV. cholerae could not Remaining source text redacted.
Why choice A is not credited
Incorrect. (Lines 24-25) This answer represents a belief of Colwell in her rebuttal to the traditional theory. -
BV. cholerae bacteria were Remaining source text redacted.
Why choice B matches the stem
Correct. Question Type:
Must Be True
Strategy Overview:
Head back to the relevant section and anticipate a specific answer
Answer Anticipation/Relevant Lines:
We noted the skepticism was present in the first half of Paragraph 2, so we should head there to check it out. There, we can see that the scientists were skeptical for two reasons:
(1) No biologist believed the bacterium could live outside of a human host
(2) No outbreaks were happening anywhere near Chesapeake, where Colwell claimed to have found cholera
One of these two must be the answer, so let's head to the choices to find one.
Answer Explanation:
(Lines 15-16) Biologists believed that V. cholerae required a human host—in other words, it couldn't persist outside of a human host, such as in sea water. This answer matches with one of the two reasons presented in the passage, so it's the correct answer.
Key Takeaway:
Note how this question's correct answer took something that we identified the specifics of and rephrased it to make it harder to spot. This is a common tactic for the harder questions/passages, so be sure to fully consider answers even when they don't match your anticipation specifically. -
CV. cholerae bacteria were Remaining source text redacted.
Why choice C is not credited
Incorrect. (Line 41) The dormant state isn't brought up until Paragraph 3, well after the biologists express skepticism. -
DColwell's new method of Remaining source text redacted.
Why choice D is not credited
Incorrect. (Lines 28-39) Colwell's new detection mechanism isn't mentioned until Line 28, well after the skepticism is introduced. -
Ethe only V. cholerae Remaining source text redacted.
Why choice E is not credited
Incorrect. (Line 30) This answer is conflating details from the Chesapeake Bay situation and the New Orleans one.
What this tests
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Answer choice distribution
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Started by sassouel