Eliöelämä

Eliöelämä, or life, is a characteristic that distinguishes physical entities with biological processes, such as signaling and self-sustaining growth, from those that do not. It is characterized by organization, metabolism, growth, adaptation, response to stimuli, and reproduction. Life is sustained by the exchange of energy and matter between an organism and its environment.

The study of life is called biology. It encompasses diverse fields, including botany, zoology, microbiology, and more. Life forms are classified into domains such as Archaea, Bacteria, and Eukarya. Each domain has unique characteristics, such as the presence or absence of a cell nucleus.

Life processes are governed by complex interactions between genes, proteins, and other molecules. These interactions are influenced by the environment, leading to adaptation and evolution. Life has a history dating back to at least 3.5 billion years ago, with the earliest forms of life being simple unicellular organisms.

Life exists in various forms, from microorganisms like bacteria and archaea to multicellular organisms like plants and animals. Each form of life has a unique life cycle, from birth or reproduction to death. Life is also characterized by the ability to respond to stimuli, such as changes in the environment, through processes like metabolism and growth.

The concept of life is fundamental to various fields, including philosophy, ethics, and religion. It raises questions about the origin of life, the nature of consciousness, and the meaning of existence. Despite the diversity of life forms, they share common principles, such as the need for energy and the ability to reproduce.