Life

*. Non-cellular life( viruses) [ note 1 ] *. Cellular life Bacteria Archaea Eukarya Protista Fungi Plantae Animalia Lifeis a characteristic distinguishing physical entitieshaving signaling and self-sustaining processesfrom those that do not, [ 1 ] [ 2 ]either because such functions have ceased ( death), or because they lack such functions and are classified as inanimate. [ 3 ] [ 4 ] Biologyis scienceconcerned with the study of life. Any contiguous living system is called an organism. Organisms undergo metabolism, maintain homeostasis, can grow, respond to stimuli, reproduceand, through evolution, adapt to their environment in successive generations. More complex organisms can communicate through alternative means. [ 1 ] [ 5 ]A diverse array of living organisms can be found in the biosphereof Earth, and the properties common to these organisms— plants, animals, fungi, protists, archaea, and bacteria—are a carbon- and water-based cellularform with complex organizationand heritable geneticinformation.