The Catalyst Perspectives Group
Characteristics of Living Things
Cellular Structure and Organized
Organisms are highly organized, coordinated structures that consist of one or more cells. Even single-celled organisms are remarkably complex. In multi-cellular organisms similar cells form tissues, tissues create organs that work together forming organ systems.
Gene-Replication, Reproduction and Inheritance
When cells replicate or reproduction occurs, DNA containing genes are passed along in the form of chromosomes. These genes ensure that the replicated cells or offspring will have parental form and function.
Metabolism and Energy-processing
All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy; others use chemical energy in molecules they take in as food.
Growth and Development
Organisms grow and develop following specific instructions coded for by their genes. Growth is the increase in size and mass of that organism. Development involves the transformation of the organism as it goes through a process which causes changes in their cells.
Homeostasis and Regulation
To function, cells need to have appropriate conditions and concentrations of diverse chemicals. Organisms maintain internal conditions despite environmental changes. Organisms use multiple mechanisms to coordinate functions, respond to stimuli, and cope with environmental conditions.
Response to Stimuli
Organisms respond to diverse stimuli. Movement toward a stimulus is considered a positive response, while movement away from a stimulus is considered a negative response. Responding appropriately at the right time and in the correct manner is an essential attribute for survival for living things.