This profile made me realize that life is is a characteristic that distinguishes physical entities that have biological processes, such as signaling and self-sustaining processes, from those that do not,either because such functions have ceased,or because they never had such functions and are classified as inanimate.Various forms of life exist, such as plants, animals,archaea,and bacteria.Biology is the science concerned with the study of life.There is currently no consensus regarding the definition of life.One popular definition is that organisms are open systems that maintain homeostasis, are composed of cells,have a life cycle,undergo metabolism,can grow,adapt to their environment,respond to stimuli, reproduce and evolve.However, several other definitions have been proposed, and there are some borderline cases of life,The prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but a gradual process of increasing complexity.