Characteristics of Life
Living things include both the visible world of animals and plants, as well as the invisible world of bacteria. On a basic level, we can say that life is ordered. Organisms have an enormously complex organization. We're all familiar with the intricate systems of the basic unit of life, the cell.
Life can also "work." No, not the daily employment variety, but living creatures can take in energy from the environment. This energy, in the form of food, is transformed to maintain metabolic processes and for survival.
Life grows and develops. This means more than just getting larger in size. Living organisms also have the ability to rebuild and repair themselves when injured.
The foundation of biology as it exists today is based on five basic principles. They are the cell theory, gene theory, evolution, homeostasis, and laws of thermodynamics.
• Cell Theory: all living organisms are composed of cells. The cell is the basic unit of life.
• Gene Theory: traits are inherited through gene transmission. Genes are located on chromosomes and consist of DNA.
• Evolution: any genetic change in a population that is inherited over several generations. These changes may be small or large, noticeable or not so noticeable.
• Homeostasis: ability to maintain a constant internal environment in response to environmental changes.
• Thermodynamics: energy is constant and energy transformation is not completely