During their larval phase, numerous species of coral reef fish are drawn toward areas where light is present. To better...
GMAT Information and Ideas : (Ideas) Questions
During their larval phase, numerous species of coral reef fish are drawn toward areas where light is present. To better understand how artificial light at night (ALAN) might affect some coral reef fish, researchers explored the effect of exposure to low levels of ALAN on the reproductive success of the common clownfish (Amphiprion ocellaris). While exposure to low levels of ALAN had no significant effect on spawning frequency and egg fertilization in A. ocellaris, incubation in the presence of ALAN completely inhibited hatching. These findings suggest that ______
Which choice most logically completes the text?
A. ocellaris that settle in areas with low levels of ALAN have significantly higher rates of successful egg fertilization than A. ocellaris that settle in areas without ALAN do.
the reproductive success of A. ocellaris would be at risk if they were to selectively settle in regions that are regularly exposed to low levels of ALAN.
the reproductive success of A. ocellaris is more greatly affected by the presence of low levels of ALAN during incubation than the reproductive success of other species of coral reef fish is.
the spawning frequency of A. ocellaris was more strongly affected by the presence of low levels of ALAN than egg fertilization was, though both were less affected than incubation.
Step 1: Decode and Map the Passage
Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "During their larval phase, numerous species of coral reef fish are drawn toward areas where light is present." |
|
| "To better understand how artificial light at night (ALAN) might affect some coral reef fish, researchers explored the effect of exposure to low levels of ALAN on the reproductive success of the common clownfish (Amphiprion ocellaris)." |
|
| "While exposure to low levels of ALAN had no significant effect on spawning frequency and egg fertilization in A. ocellaris," |
|
| "incubation in the presence of ALAN completely inhibited hatching." |
|
Provide Passage Architecture & Core Elements
Main Point: Research shows that while artificial light at night doesn't affect early reproductive stages in clownfish, it completely prevents successful hatching.
Argument Flow: The passage establishes that coral fish larvae are attracted to light, then describes a study testing how artificial nighttime light affects clownfish reproduction. The key finding reveals a stark contrast—ALAN doesn't impact spawning or fertilization, but it completely blocks hatching, creating a clear reproductive problem.
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
- The research shows a critical problem: ALAN completely stops hatching even though it doesn't affect earlier reproductive stages
- This means clownfish could go through spawning and fertilization normally, but then fail completely at the final step
- If clownfish settle in areas with artificial light, they would face reproductive failure because their eggs simply won't hatch
A. ocellaris that settle in areas with low levels of ALAN have significantly higher rates of successful egg fertilization than A. ocellaris that settle in areas without ALAN do.
✗ Incorrect
- Claims clownfish in ALAN areas have higher fertilization rates
- Contradicts the passage which states ALAN had "no significant effect" on fertilization
the reproductive success of A. ocellaris would be at risk if they were to selectively settle in regions that are regularly exposed to low levels of ALAN.
✓ Correct
- States reproductive success would be at risk in ALAN regions
- This matches our analysis—complete hatching failure means reproductive failure
the reproductive success of A. ocellaris is more greatly affected by the presence of low levels of ALAN during incubation than the reproductive success of other species of coral reef fish is.
✗ Incorrect
- Compares clownfish ALAN effects to other coral reef fish species
- The passage provides no data about other species' responses
the spawning frequency of A. ocellaris was more strongly affected by the presence of low levels of ALAN than egg fertilization was, though both were less affected than incubation.
✗ Incorrect
- Claims spawning was more affected than fertilization
- Contradicts the passage which states both showed "no significant effect"