Bacteria Bacteria Bacteria (; common noun bacteria, singular bacterium) are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about half of the
Flora and fauna of Karachi plants is "flora". Flora, fauna and other forms of life such as fungi are collectively referred to as biota. Also crows, pigeons, doves, sparrows, parrots, hawks, eagles and seagulls. Flora and fauna of Karachi The flora and fauna of Karachi, Sindh, Pakistan. Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animal life is fauna. "Flora", "fauna" and other forms of life such as fungi are collectively referred to as biota. Bacterial organisms, algae, and other organisms are sometimes referred to as flora, so that