[1] In the depths of the ocean, hydrothermal vents support unique ecosystems that thrive completely independent of sunlight. [2] Instead of relying on photosynthesis, the primary producers in these environments—specialized bacteria—utilize chemosynthesis to convert chemical energy from the vents' mineral-rich fluids into organic matter. [3] These chemosynthetic bacteria often form symbiotic relationships with larger organisms, such as giant tube worms, which lack mouths and digestive tracts. [4] Tube worms possess bright red plumes filled with hemoglobin that absorb hydrogen sulfide and oxygen from the water. [5] The bacteria reside inside a specialized organ within the tube worm called a trophosome, where they use the raw materials delivered by the worm's bloodstream to produce nutrients. [6] This elegant partnership demonstrates how life can adapt to survive in some of the most extreme conditions on Earth.
The writer is considering deleting Sentence 4 from the passage. Should this sentence be kept or deleted?
- Kept, because it explains how the tube worms acquire the chemical compounds that the symbiotic bacteria use to generate nutrients.Answer
- BKept, because it provides descriptive imagery that helps the reader visualize the harsh environment surrounding hydrothermal vents.
- CDeleted, because it introduces descriptive details about the tube worms' appearance that distract from the paragraph's explanation of chemosynthesis.
- DDeleted, because it repeats information about the raw materials used in chemosynthesis that was already established in Sentence 2.