There are 6 Themes
that this book and the study of Biology will continually refer back to.
These themes give guidelines in which to define "LIFE." These
are:1. Cell structure and function - All cells are composed of
cells. Some are unicellular and self contained while some are
multicellular with each cell type performing a generalized life
function. All cells have membranes that surround them and all
contain a nucleus that contain DNA that controls its activities
2. Stability and Homeostasis - Homeostasis is maintaining a
constant internal condition. All cells must control its' internal
environment and act to change it if it is to survive. A cell must
also be able to "sense" any change in its' environment and react
accordingly
3. Heredity - Heredity is the transmission of "developmental
instructions from parents to offspring. If damage (mutation) occurs
it must correct the change or pass it down to its offspring.
Mutation is what allows evolution to take place.
4. Evolution - Inherited change in a populations characteristics
over time.
5. Interdependence - All things rely on each other either
directly or indirectly
6. Matter energy and organization - All organisms are composed of
atoms, which assemble into molecules. cells are made of molecules.
All life requires energy and life is organized into many levels.