FUNDAMENTAL PROPERTIES OF LIFE

What are the fundamental properties of life?

As we discussed in chapter 1, all known organisms share certain general properties. To a large degree, these proper-ties define what we mean by life. The following fundamental properties are shared by all organisms on earth.

Cellular organization. All organisms consist of one or more cells—complex, organized assemblages of molecules enclosed within membranes.

Sensitivity. All organisms respond to stimuli—though not always to the same stimuli in the same ways.  

Growth.  All living things assimilate energy and use it to maintain order and grow, a process called metabolism. Plants, algae, and some bacteria use sunlight to create covalent carbon-carbon bonds from CO2 and H2O through photosynthesis. This transfer of the energy in covalent bonds is essential to all life on earth. 

Development. Both unicellular and multicellular organisms undergo systematic, gene-directed changes as they grow and mature.
  
Reproduction. All living things reproduce, passing on individuals from one generation to the next.  

Regulation. All organisms have regulatory mechanisms that coordinate internal processes. 

Homeostasis. All living things maintain relatively constant internal conditions, different from their environment.