Bacteria are single-celled, prokaryotic microorganisms that lack a nucleus and membrane-bound organelles. They can be found in nearly every habitat on Earth and have diverse metabolic capabilities.
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Bacteria are classified into various groups based on their shape, such as cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
Proteobacteria is a major phylum of Gram-negative bacteria that includes a wide variety of pathogens, such as Escherichia coli and Salmonella.
Bacteria reproduce primarily through binary fission, a process where a single cell divides into two identical daughter cells.
Many bacteria form symbiotic relationships with other organisms, including humans; some are beneficial while others can cause diseases.
Bacterial habitats range from extreme environments like hot springs and deep-sea vents to more common places like soil, water, and the human gut.
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Prokaryote: An organism that lacks a distinct nucleus and membrane-bound organelles.