Biologist Natacha Bodenhausen and colleagues analyzed the naturally occurring bacterial communities associated with leaves and roots of wild Arabidops...
GMAT Information and Ideas : (Ideas) Questions
Biologist Natacha Bodenhausen and colleagues analyzed the naturally occurring bacterial communities associated with leaves and roots of wild Arabidopsis thaliana, a small flowering plant. The researchers found many of the same bacterial genera in both the plants' leaves and roots. To explain this, the researchers pointed to the general proximity of A. thaliana leaves to the ground and noted that rain splashing off soil could bring soil-based bacteria into contact with the leaves. Alternatively, the researchers noted that wind, which may be a source of bacteria in the aboveground portion of plants, could also bring bacteria to the soil and roots. Either explanation suggests that ______
Which choice most logically completes the text?
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| Biologist Natacha Bodenhausen and colleagues analyzed the naturally occurring bacterial communities associated with leaves and roots of wild Arabidopsis thaliana, a small flowering plant. |
|
| The researchers found many of the same bacterial genera in both the plants' leaves and roots. |
|
| To explain this, the researchers pointed to the general proximity of A. thaliana leaves to the ground and noted that rain splashing off soil could bring soil-based bacteria into contact with the leaves. |
|
| Alternatively, the researchers noted that wind, which may be a source of bacteria in the aboveground portion of plants, could also bring bacteria to the soil and roots. |
|
| Either explanation suggests that ______ |
|
Part B: Passage Architecture & Core Elements
Main Point: Researchers found the same bacterial types in both leaves and roots of A. thaliana and proposed two mechanisms that could explain this overlap.
Argument Flow: The passage starts with a surprising research finding (same bacteria in different plant parts), then offers two different explanations for how this could happen (rain moving soil bacteria up, or wind moving airborne bacteria down), leading to a logical conclusion about what both explanations imply.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- Looking at both explanations, we see a common theme
- The rain explanation suggests soil bacteria can end up on leaves
- The wind explanation suggests airborne bacteria can end up in soil/roots
- Both explanations involve bacteria moving between different locations or sources and ending up in multiple places
- The key insight is that if bacteria can move from soil to leaves (via rain) OR from air to both soil and leaves (via wind), then the bacteria found in leaves and roots might not have originated in those specific locations - they could have come from elsewhere
- So the right answer should capture the idea that bacteria in different parts of the plant may have originated from the same source or location, rather than developing independently in each plant part
- Claims wind-carried bacteria are less beneficial than soil-based bacteria
- This makes a comparison about bacterial benefits that isn't discussed in the passage
- Neither explanation addresses which bacteria are more beneficial
- States that bacteria in leaves and roots may share a common source
- This perfectly captures what both explanations suggest: rain can bring soil bacteria to leaves (common source: soil), while wind can bring the same airborne bacteria to both locations (common source: air)
- Matches our prethinking about bacteria originating from shared locations
- Focuses only on leaf bacteria being deposited by non-rain methods
- This is too narrow - it only addresses one explanation (wind) and ignores the rain explanation entirely
- Claims leaves and roots are vulnerable to harmful bacteria
- The passage doesn't discuss whether the bacteria are harmful or beneficial
- Neither explanation addresses plant vulnerability