Algae living within the tissues of corals play a critical role in keeping corals, and the marine ecosystems they are...

GMAT Information and Ideas : (Ideas) Questions

Source: Official

Information and Ideas

Central Ideas and Details

HARD

...

Notes

Post a Query

Algae living within the tissues of corals play a critical role in keeping corals, and the marine ecosystems they are part of, thriving. Some coral species appear brown in color when healthy due to the algae colonies living in their tissues. In the event of an environmental stressor, the algae can die or be expelled, causing the corals to appear white. To recover the algae, the bleached corals then begin to produce bright colors, which block intense sunlight, encouraging the light-sensitive algae to recolonize the corals.

What does the text most strongly suggest about corals that produce bright colors?

These corals have likely been subjected to stressful environmental conditions.

These corals are likely more vulnerable to exposure from intense sunlight than white corals are.

These corals have likely recovered from an environmental event without the assistance of algae colonies.

These corals are more likely to survive without algae colonies than brown corals are.

Solution

Step 1: Decode and Map the Passage

Create Passage Analysis Table

Text from Passage	Analysis
"Algae living within the tissues of corals play a critical role in keeping corals, and the marine ecosystems they are part of, thriving."	What it says: Algae in corals = critical for coral + ecosystem health. What it does: Introduces the importance of algae to coral survival. What it is: Background context
"Some coral species appear brown in color when healthy due to the algae colonies living in their tissues."	What it says: Healthy corals = brown (because of algae). What it does: Explains what healthy corals look like and why. What it is: Descriptive detail
"In the event of an environmental stressor, the algae can die or be expelled, causing the corals to appear white."	What it says: Environmental stress → algae die/leave → corals turn white. What it does: Describes what happens when corals are stressed. What it is: Process explanation
"To recover the algae, the bleached corals then begin to produce bright colors, which block intense sunlight, encouraging the light-sensitive algae to recolonize the corals."	What it says: White corals → make bright colors → block sun → algae return. What it does: Explains the recovery mechanism for stressed corals. What it is: Solution process

Provide Passage Architecture & Core Elements

Main Point: Corals have a recovery mechanism where they produce bright colors to create conditions that help algae return after environmental stress.

Argument Flow: The passage establishes that algae are essential for coral health, then explains how environmental stress disrupts this relationship by killing or expelling algae, and finally describes how corals respond by producing bright colors to encourage algae to return.

Step 2: Interpret the Question Precisely

What's being asked? What we can infer about corals that produce bright colors.
What type of answer do we need? A logical conclusion based on the passage information.
Any limiting keywords? "most strongly suggest" means we need the most supported inference.

Step 3: Prethink the Answer

From our analysis, we know bright colors are produced by bleached (white) corals
We also know corals become bleached when they experience environmental stress
So corals that produce bright colors must be corals that have gone through the stress → bleaching → recovery sequence
The key insight is following the chain backward: if we see bright colors, that means the coral was previously bleached, and if it was bleached, that means it experienced environmental stress

Answer Choices Explained

These corals have likely been subjected to stressful environmental conditions.

✓ Correct

This perfectly matches our logical chain: bright colors come from bleached corals, and bleaching happens due to environmental stressors
The word "likely" appropriately reflects that this is an inference based on the described process

These corals are likely more vulnerable to exposure from intense sunlight than white corals are.

✗ Incorrect

This misunderstands the relationship - bright colors actually protect corals from intense sunlight
The passage says bright colors "block intense sunlight," making these corals less vulnerable, not more

These corals have likely recovered from an environmental event without the assistance of algae colonies.

✗ Incorrect

This contradicts the passage - bright colors are produced specifically to help algae colonies return
The entire point of the bright colors is to "encourage the light-sensitive algae to recolonize"

These corals are more likely to survive without algae colonies than brown corals are.

✗ Incorrect

The passage provides no comparison between bright-colored corals and brown corals regarding survival without algae
All corals need algae according to the passage - the bright colors are an attempt to get them back, not evidence of independence

Rate this Solution

Tell us what you think about this solution

...

Forum Discussions

Start a new discussion

Post

Previous Attempts

Loading attempts...