What are bacteria?

Bacteria are one-celled microorganisms that belong to the domain of prokaryotes. These organisms are characterized by their simple cellular structure, lacking a defined nucleus and membrane-bound organelles. Bacteria can vary in shape, size, and function, and they can exist in a wide range of environments, from soil and water to the human body.

Their one-celled nature allows them to reproduce rapidly and adapt to their surroundings, making them essential for various ecological roles, such as nutrient cycling and decomposition. Some bacteria can be harmful, causing diseases, while others are beneficial and crucial for processes like fermentation and digestion.

In contrast, multi-celled organisms include plants and animals, which are composed of many cells that work together, and virus-like particles do not possess cellular structures, as they cannot replicate independently outside a host. Fungi and algae represent different kingdoms of life with their own distinct cellular structures and life processes.