Final answer:
Bacteria are heterotrophic organisms that obtain their energy and nutrients by consuming other organisms or organic matter. They cannot produce their own food through photosynthesis. Examples include saprophytic, parasitic, and decomposer bacteria.
Step-by-step explanation:
Bacteria are classified as heterotrophic organisms, meaning they obtain their energy and nutrients by consuming other organisms or organic matter. They are unable to produce their own food through photosynthesis like autotrophic organisms such as plants and algae do.
Bacteria can have various modes of obtaining their nutrients. Some bacteria are saprophytic, feeding on dead organic matter. Others are parasitic, deriving their nutrients from a host organism. Some bacteria are also capable of decomposing organic matter, playing a critical role in the recycling of nutrients in ecosystems.
For example, the bacterium Escherichia coli, commonly found in the intestines of humans and other animals, is heterotrophic and obtains its nutrients by breaking down complex organic compounds present in the digestive system.
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