TLDR: Life is the quality that makes living things different from non-living things. It includes things like growth, reproduction, and the ability to respond to stimuli. There are different forms of life, such as plants, animals, fungi, and bacteria. Biology is the science that studies life.
Life is a complex process that distinguishes living things from non-living things. It involves various characteristics, such as the ability to grow, react to stimuli, metabolize, transform energy, and reproduce. Living things can be plants, animals, fungi, archaea, or bacteria. The study of life is called biology.
Living things are made up of cells, which are the basic units of life. There are two types of cells: prokaryotic cells, which are simpler and do not have a nucleus, and eukaryotic cells, which are more complex and have a nucleus. Cells reproduce through cell division, passing their genes onto new generations.
Living organisms are considered open systems that maintain homeostasis, meaning they regulate their internal environment to maintain a stable state. They undergo metabolism, which involves converting energy and chemicals into cellular components. They can also grow, adapt to their environment, respond to stimuli, reproduce, and evolve over time.
Life on Earth has evolved from simple forms to more complex ones through a process called natural selection. This process involves genetic variation and the survival of individuals with traits that are better suited to their environment. Today, there are millions of different species on Earth.
Death is the permanent termination of all biological processes that sustain an organism, while extinction refers to the dying-out of a species. Fossils are the preserved remains or traces of organisms that provide evidence of past life.
The definition of life has been a challenge for scientists and philosophers. There are various definitions, but most describe life as a characteristic of something that maintains its existence in a given environment. This includes traits like homeostasis, organization, metabolism, growth, adaptation, response to stimuli, and reproduction.
Some definitions of life also consider the ability to evolve and maintain distinctness as important factors. Others focus on the thermodynamics of living systems or the emergence of complexity in functional organisms. There are also theories that view life from a systemic perspective, considering the interactions between living things and their environment.
The study of life has a long history, with ancient philosophers and scientists proposing materialistic explanations for the nature of life. The advances in cell theory and the theory of evolution in the 19th and 20th centuries furthered our understanding of life.