Microbial cells are the basic units of life for microorganisms, which include bacteria, archaea, fungi, and some algae. These cells are typically much smaller than plant and animal cells, often measuring just a few micrometers in size. They can exist as single cells or form colonies, and they play essential roles in various ecosystems, including nutrient cycling and decomposition. Microbial cells have diverse structures and functions. For example, bacteria often have a rigid cell wall that provides shape and protection, while fungi possess cell walls made of chitin. These cells can reproduce rapidly, adapt to different environments, and some can even form spores to survive harsh conditions.