What type of bacteria is classified as self-nourishing?

The classification of bacteria as self-nourishing is correctly identified as autotrophic. Autotrophic bacteria are capable of synthesizing their own food from inorganic substances using light or chemical energy. This means they can convert carbon dioxide and other inorganic materials into organic compounds essential for their growth and metabolism.

In contrast, heterotrophic bacteria rely on organic compounds from the environment for their nourishment, making them dependent on other organisms for energy. Pathogenic bacteria are those that can cause disease, but this classification does not pertain to their nutritional strategy. Symbiotic bacteria exist in a mutually beneficial relationship with other organisms, which may or may not involve self-nourishment.

Understanding the distinction in nutritional modes helps clarify the self-sufficiency of autotrophic bacteria in their role within various ecosystems, where they can contribute to primary production by providing energy and organic molecules for other organisms.