GED Science TestEarth and Space ScienceHard
A team of researchers is studying a deep-sea hydrothermal vent ecosystem. They observe a thriving community of organisms, including tube worms and bacteria, flourishing in the absence of sunlight. Which process is the primary energy source for the producers in this unique ecosystem?
- ADecomposition
- BPhotosynthesis
- CGeothermal heating
- DChemosynthesis
Show answer & explanationAnswer & explanation
Correct answer: D. Chemosynthesis
Hydrothermal vent ecosystems are located in the deep ocean where no sunlight penetrates. Therefore, life cannot rely on photosynthesis. Instead, specialized bacteria perform chemosynthesis, using chemical energy from hydrogen sulfide and other compounds released from the vents to produce organic matter, forming the base of the food web.
Why the other options are wrong
- A. Decomposition recycles nutrients but is not a primary energy source for producers.
- B. Photosynthesis requires sunlight, which is absent in deep-sea vents.
- C. Geothermal heating provides warmth but not direct energy for organic matter production.
Chemosynthesis
The biological conversion of one or more carbon molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic chemical compounds (e.g., hydrogen sulfide) as an energy source, rather than sunlight.
- Common in deep-sea hydrothermal vents and other environments without sunlight.
- Forms the base of the food web in these ecosystems.
- Performed by chemosynthetic bacteria and archaea.
Memory trick: No Sun, No Photosynthesis, Chemical Feast for Life's Genesis.