Entomologists Yash Sondhi and Samuel Fabian have tried to explain why moths fly erratically around light sources at night. Knowing...
GMAT Standard English Conventions : (Grammar) Questions
Entomologists Yash Sondhi and Samuel Fabian have tried to explain why moths fly erratically around light sources at night. Knowing that flying insects keep their backs pointed toward sunlight during the day, ________
Which choice completes the text so that it conforms to the conventions of Standard English?
the researchers theorize that moths, mistaking nighttime lights for the Sun, continually try to reorient their bodies while flying near such lights.
the researchers' theory is that moths mistake nighttime lights for the Sun, continually trying to reorient their bodies while flying near such lights.
moths mistake nighttime lights for the Sun and continually try to reorient their bodies while flying near such lights, the researchers theorize.
moths continually try to reorient their bodies while flying near nighttime lights, the researchers theorize, mistaking such lights for the Sun.
Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!
Sentence Structure
- Entomologists Yash Sondhi and Samuel Fabian
- have tried to explain
- why moths fly erratically around light sources at night.
- have tried to explain
- Knowing that flying insects keep their backs pointed toward sunlight during the day,
- [?] (What varies in the choices:
- - Subject after comma: "the researchers" OR "moths"
- - Structure and placement of other elements)
- [?] (What varies in the choices:
Understanding the Meaning
Let's start by reading from the beginning:
'Entomologists Yash Sondhi and Samuel Fabian have tried to explain why moths fly erratically around light sources at night.'
So we have two researchers studying a specific puzzle:
- Why do moths fly in that erratic, unpredictable way around lights?
Then the sentence continues:
'Knowing that flying insects keep their backs pointed toward sunlight during the day,'
This is where we have the blank. Let's look at the choices:
- Choices A and B start with "the researchers" (or "the researchers' theory")
- Choices C and D start with "moths"
To see what works here, let's understand what this opening phrase is doing!
The phrase "Knowing that flying insects keep their backs pointed toward sunlight during the day" is describing someone who possesses this knowledge.
Now here's the crucial question: Who knows this scientific information?
- The researchers (Yash Sondhi and Samuel Fabian) know this fact about insect behavior
- They're scientists studying this
- This knowledge is part of their research
- The moths don't "know" this in a scientific sense
- Moths act on instinct, not scientific knowledge
- They don't study their own behavior patterns
What do we notice about the structure here?
When a describing phrase like "Knowing that..." starts a sentence and is followed by a comma, it must describe whoever or whatever comes immediately after that comma.
- The phrase "Knowing that flying insects keep their backs pointed toward sunlight during the day" must modify the subject that follows the comma.
- Since the researchers are the ones who possess this knowledge (not the moths), the subject following the comma must be "the researchers."
So we need Choice A or B - both correctly place the researchers (or reference to them) after the comma.
Between A and B:
- Choice A: "the researchers theorize..."
- Direct and clear - the researchers are the subject doing the theorizing
- Choice B: "the researchers' theory is..."
- Makes "theory" the grammatical subject
- More awkward because the phrase "Knowing that..." should modify the people who know (the researchers themselves), not an abstract concept (theory)
- Theories don't "know" things - people do
The correct answer is Choice A.
GRAMMAR CONCEPT APPLIED
Descriptive Phrases at the Start of a Sentence Must Modify What Comes Next
When a descriptive phrase (called a participial phrase in grammar terms) appears at the beginning of a sentence and is followed by a comma, it must directly modify the subject that immediately comes after the comma:
Pattern:
- Descriptive phrase + comma + [must be the noun being described]
Example 1:
- Correct: "Knowing the answer, the student raised her hand."
- Who knows the answer? The student.
- "The student" correctly follows the comma.
- Incorrect: "Knowing the answer, the hand was raised."
- The hand doesn't know the answer - this creates a misplaced modifier.
Example 2:
- Correct: "Walking through the forest, we spotted a deer."
- Who was walking? We were.
- Incorrect: "Walking through the forest, a deer was spotted."
- The deer wasn't walking through the forest (we were) - misplaced modifier.
In this question:
- The phrase "Knowing that flying insects keep their backs pointed toward sunlight during the day"
- Must be followed by whoever possesses this knowledge = the researchers
- Not the moths (they don't possess scientific knowledge about their behavior)
the researchers theorize that moths, mistaking nighttime lights for the Sun, continually try to reorient their bodies while flying near such lights.
✓ Correct
Correct as explained in the solution above.
the researchers' theory is that moths mistake nighttime lights for the Sun, continually trying to reorient their bodies while flying near such lights.
✗ Incorrect
"the researchers' theory is that moths mistake nighttime lights for the Sun, continually trying to reorient their bodies while flying near such lights."
- The subject of this clause is "theory," not "researchers"
- The phrase "Knowing..." needs to modify someone who can possess knowledge
- A theory can't "know" things – only people can
- This creates what's called a misplaced modifier
moths mistake nighttime lights for the Sun and continually try to reorient their bodies while flying near such lights, the researchers theorize.
✗ Incorrect
"moths mistake nighttime lights for the Sun and continually try to reorient their bodies while flying near such lights, the researchers theorize."
- The subject that comes right after "Knowing..." is "moths"
- This creates a misplaced modifier because moths don't "know" scientific facts about insect behavior in this conscious way
- The researchers are the ones who know this fact, so they need to be the subject
moths continually try to reorient their bodies while flying near nighttime lights, the researchers theorize, mistaking such lights for the Sun.
✗ Incorrect
"moths continually try to reorient their bodies while flying near nighttime lights, the researchers theorize, mistaking such lights for the Sun."
- Same error as C – "moths" is the subject following the modifying phrase
- Moths don't possess the scientific knowledge described in "Knowing..."
- Additionally, putting "mistaking such lights for the Sun" at the end creates confusion about who's doing the mistaking