- Life Sciences
a large domain of prokaryotic micro-organisms. They are typically a few micrometres in length having a wide range of shapes, ranging from spheres called cocci, rod-shaped, called bacilli, slightly curved or comma-shaped, called vibrio, spiral-shaped, called spirilla, to tightly coiled, called spirochaetes. A small number of species even have tetrahedral or cuboidal shapes. Bacteria are present in most habitats on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals.
a state in which the body has become dependent on a chemical substance in order to function.
thin-walled or slightly strengthened, elongated phloem cells that conduct food substances.
list of questions or statements that are used to classify or identify a living organism.