Read the passage below and answer the question:

"Deep-sea hydrothermal vents exist in complete darkness under crushing hydrostatic pressures. Instead of relying on solar photosynthesis, primary production in these abyssal ecosystems is driven entirely by chemolithoautotrophic bacteria that oxidize dissolved hydrogen sulfide emitted by volcanic vents, providing organic biomass for giant tube worms, crabs, and specialized mollusks."

What forms the energetic foundation of deep-sea hydrothermal vent ecosystems?

Answer and explanation

Correct answer: C. bacterial chemosynthesis utilizing volcanic hydrogen sulfide

  1. Step 1: Locate the explicit biological mechanism: 'primary production in these abyssal ecosystems is driven entirely by chemolithoautotrophic bacteria that oxidize dissolved hydrogen sulfide'.
  2. Step 2: Chemosynthetic bacteria utilizing geothermal sulfur form the base of the food web.
Answer
bacterial chemosynthesis utilizing volcanic hydrogen sulfide.
Why not the others: 'phytoplankton photosynthesis sustained by filtered surface sunlight' is impossible in complete oceanic darkness; 'direct thermal conversion of boiling magma into animal proteins' is scientifically impossible; 'the passive accumulation of falling organic debris from coastal runoff' describes marine snow, which the passage explicitly contrasts with hydrothermal primary production.

Practise more Academic Reading Comprehension, Critical Reasoning, and Text Analysis.

Free questions with an explanation for every one, and full timed MUET Malaysia (Malaysian University English Test) mock tests.

All Academic Reading Comprehension, Critical Reasoning, and Text Analysis questionsTake a mock test

More Academic Reading Comprehension, Critical Reasoning, and Text Analysis questions