Final answer:
Deep-sea bacteria use chemosynthesis to produce sugars, relying on chemical energy from inorganic molecules instead of sunlight, supporting unique ecosystems around hydrothermal vents.
Step-by-step explanation:
The types of bacteria that live in deep ocean environments where sunlight is not available use a process called chemosynthesis to make sugars. Unlike photosynthetic organisms that require sunlight to produce organic compounds, these bacteria obtain energy by oxidizing inorganic molecules such as hydrogen sulfide or ammonia. An example of this chemical reaction is the conversion of carbon dioxide, oxygen, and hydrogen sulfide into carbohydrates, sulfur, and water:
CO₂ + O₂ + 4H₂S → CH₂O + 4S + 3H₂O
This process supports unique ecosystems around hydrothermal vents, also known as "black smokers," where a diverse array of animals, such as tubeworms, crustaceans, and octopuses depend on chemoautotrophic bacteria for their energy needs.