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Marine Biology Discovery

Central Ideas & Details • Set 1

Answer: B

PASSAGE

The following text describes a discovery in marine biology.

In 2023, researchers from the Coastal Marine Institute discovered a new species of jellyfish in the deep waters off the California coast. Unlike typical jellyfish, this species produces bioluminescence in complex patterns that appear to communicate information to other members of its species. The discovery suggests that jellyfish may be far more socially sophisticated than scientists previously believed.

Which choice best states the main idea of the text?

A. A new jellyfish species produces unique light patterns
B. The discovery of a new jellyfish species suggests they may have unexpected social abilities✓ Correct
C. California's deep waters contain many undiscovered species
D. Bioluminescence is common among marine creatures

Detailed Explanation

Choice B is the correct answer. The passage describes a discovery and emphasizes that the bioluminescent patterns "appear to communicate information," leading to the conclusion that jellyfish "may be far more socially sophisticated" than believed.

Key Evidence:

  • Patterns "appear to communicate information"
  • Discovery "suggests" social sophistication
  • Main idea connects discovery to broader implication

Why other choices are wrong:

  • A: Only describes the discovery without the main implication about social behavior.
  • C: Too broad—the text focuses on one specific species, not undiscovered species in general.
  • D: Also too broad—the text discusses one specific case, not bioluminescence in general.

💡 SAT Strategy Tip:

For "main idea" questions, look for the choice that captures both WHAT happened and WHY it matters. Choice B does both.

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