In 2017, a research team led by Mary Caswell Stoddard determined the average lengths of eggs produced by various bird...
GMAT Expression of Ideas : (Expression) Questions
In 2017, a research team led by Mary Caswell Stoddard determined the average lengths of eggs produced by various bird species.
Gygis alba is a species of bird in the order Charadriiformes.
Gygis alba eggs had an average length of 4.46 cm.
Gavia stellata is a species of bird in the order Gaviiformes.
Gavia stellata eggs had an average length of 7.22 cm.
Which choice most effectively uses information from the given sentences to emphasize a difference between the eggs of the two species?
A 2017 study compared the lengths of eggs produced by an array of different bird species, such as Gygis alba and Gavia stellata.
A 2017 study found that Gygis alba eggs had an average length of \(4.46\text{ cm}\), whereas Gavia stellata eggs were longer, with an average length of \(7.22\text{ cm}\).
The bird species Gygis alba, which belongs to the order Charadriiformes, and Gavia stellata, of the order Gaviiformes, were included in a 2017 study that compared the average lengths of their eggs.
Mary Caswell Stoddard led a research study that determined the average lengths of eggs, including those of Gygis alba birds (\(4.46\text{ cm}\)) and Gavia stellata birds (\(7.22\text{ cm}\)).
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "In 2017, a research team led by Mary Caswell Stoddard determined the average lengths of eggs produced by various bird species." |
|
| "Gygis alba is a species of bird in the order Charadriiformes." |
|
| "Gygis alba eggs had an average length of 4.46 cm." |
|
| "Gavia stellata is a species of bird in the order Gaviiformes." |
|
| "Gavia stellata eggs had an average length of 7.22 cm." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: A 2017 research study measured egg lengths for different bird species, revealing that Gavia stellata eggs (7.22 cm) are significantly longer than Gygis alba eggs (4.46 cm).
Step 2: Interpret the Question Precisely
What's being asked? Which choice most effectively emphasizes the difference between the eggs of the two species.
What type of answer do we need? The most effective rhetorical presentation that highlights the contrast between the egg sizes.
Any limiting keywords? Key insight: We need language that actively draws attention to the contrast, not just neutral data presentation.
Step 3: Prethink the Answer
- The correct choice needs to include both egg length measurements (4.46 cm vs 7.22 cm) and use contrastive language that highlights the difference
- Words like "whereas," "while," "longer," or "compared to" would signal emphasis on difference
A 2017 study compared the lengths of eggs produced by an array of different bird species, such as Gygis alba and Gavia stellata.
✗ Incorrect
- Simply states that the study "compared" different species but gives no actual measurements
- Doesn't emphasize difference because it provides no data
A 2017 study found that Gygis alba eggs had an average length of \(4.46\text{ cm}\), whereas Gavia stellata eggs were longer, with an average length of \(7.22\text{ cm}\).
✓ Correct
- Provides both specific measurements (\(4.46\text{ cm}\) vs \(7.22\text{ cm}\))
- Uses "whereas" to create direct contrast
- Explicitly states that one species' eggs were "longer" - actively emphasizing the difference
The bird species Gygis alba, which belongs to the order Charadriiformes, and Gavia stellata, of the order Gaviiformes, were included in a 2017 study that compared the average lengths of their eggs.
✗ Incorrect
- Focuses on taxonomic orders rather than egg size difference
- Doesn't provide the actual measurements that show the contrast
Mary Caswell Stoddard led a research study that determined the average lengths of eggs, including those of Gygis alba birds (\(4.46\text{ cm}\)) and Gavia stellata birds (\(7.22\text{ cm}\)).
✗ Incorrect
- Includes both measurements but presents them neutrally without contrastive language to emphasize the significant size difference