What is Life?

Life can be defined as the condition that distinguishes organisms from inorganic objects and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to the environment through changes originating internally.

Characteristics of Life

Cellular Organization: All living things are composed of one or more cells.
Growth and Development: Living organisms grow and undergo changes in form and function over their lifetime.
Reproduction: Living organisms can reproduce and create offspring.
Response to Stimuli: Organisms respond to their environment and can detect and respond to changes in their surroundings.
Homeostasis: Living organisms maintain a stable internal environment despite external changes.
Heredity: Living organisms pass on genetic information to their offspring.
Adaptation: Living organisms can adapt to their environment through the process of natural selection.

There are three main domains of life:

Archaea: Single-celled microorganisms that are similar to bacteria but have different evolutionary histories.
Bacteria: Single-celled microorganisms that can be found in various environments.
Eukarya: Organisms with complex cells, including plants, animals, fungi, and protists.

Living organisms carry out various life processes to maintain their existence:

Metabolism: The chemical processes that occur within a living organism to maintain life.
Respiration: The process of obtaining energy from the intake of oxygen and release of carbon dioxide.
Photosynthesis: The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.
Excretion: The process of eliminating waste products from the body.
Nutrition: The process by which organisms obtain and use food for growth, maintenance, and repair.