Fundamental Life Functions or Processes
Organization: Living things are structurally organized, typically at the cellular level (unicellular or multicellular).
Higher levels of organization include tissues, organs, and organ systems. All organisms contain highly complex biochemical molecules.
Metabolism: The sum of all chemical reactions occurring within an organism. It includes:
Anabolism: Building complex molecules from simpler ones (e.g., protein synthesis).
Catabolism: Breaking down complex molecules into simpler ones to release energy (e.g., cellular respiration).
Growth & Development: Organisms increase in size due to cell enlargement or cell division. Development involves specific changes in form, structure, or function as the organism matures (e.g., seed to plant, caterpillar to butterfly).
Reproduction: The ability to produce new individuals, either asexually (offspring genetically identical to parent) or sexually (offspring genetically distinct from parents). This ensures the continuation of the species.
Response to Stimuli (Irritability): The ability to detect and react to changes in the internal or external environment (e.g., plants bending towards light, animals fleeing predators, pupils dilating in dim light).
Homeostasis: The maintenance of a stable internal environment despite changes in the external environment.
This involves complex regulatory mechanisms (e.g., temperature regulation, blood pH balance, water balance).
Adaptation & Evolution: Populations of organisms change over generations (evolve) through natural selection.
Adaptations (inherited traits) develop that enhance survival and reproduction in specific environments.
Movement: This encompasses:
Locomotion: Movement of the whole organism from place to place (e.g., walking, flying, swimming).
Movement of Substances: Internal movement within the organism (e.g., cytoplasmic streaming in cells, blood circulation, transport of water in plants).
Digestion: The process of breaking down complex food substances (macromolecules) obtained from the environment into smaller, simpler molecules that can be absorbed into the bloodstream and utilized by the cells of the body for energy, growth, and repair.
Excretion: The removal of metabolic waste products from the body. These wastes are toxic if allowed to accumulate (e.g., carbon dioxide from respiration, nitrogenous wastes like urea from protein breakdown).
These processes are interdependent and essential for an organism to be considered alive and to maintain life.