The food web above represents feeding relationships in a biological community near a deep-sea hydrothermal vent. Hydrothermal ve
nts are geysers on the seafloor that gush super-heated, mineral-rich water. The seawater surrounding hydrothermal vents typically contains carbon dioxide (CO2), molecular hydrogen (H2), hydrogen sulfide (H2S), and methane (CH4). Sunlight, however, fails to reach the seafloor where deep-sea hydrothermal vents are located.As part of an investigation, researchers collected living specimens from an area near a deep-sea hydrothermal vent. Mussels in the collection were found to be dependent on molecular hydrogen in seawater. Also, the researchers discovered multiple species of bacteria living in the gills of the mussels. Mussels use gills for filter-feeding and gas exchange with the surrounding seawater. On the basis of their experimental results, the researchers hypothesized that some bacteria living in the gills of the mussels are capable of chemosynthesis. Based on an analysis of the food web, an observation that deep-sea bacteria consume molecular hydrogen (H2) is most relevant to resolving which of the following apparent contradictions? Some organisms rely on energy captured from inorganic compounds to drive basic biological processes.
Some deep-sea organisms appear to be primary consumers, but no plants live near the hydrothermal vents.
