Themes of Biology
Definition of Biology
Biology is the study of life, or all living things.
An individual living thing is referred to as an organism.
There are 6 main themes of biology.
1. Cell Structure and Function
The cell is the basic unit of life. Some organisms are unicellular—have only one
cell. Other organisms are multicellular—composed
of more than one cell. Cells are highly organized and contain
specialized structures that carry out different processes.
Multicellular organisms usually have differentiated cells. (Different cells perform different functions.)
2. Stability and Homeostasis
This is the ability of a cell to maintain a stable level of internal conditions.
For example, humans maintain a stable body temperature under controlled or normal conditions.
3. Reproduction and Inheritance
Reproduction—the process where organisms transmit hereditary information to their offspring.
This hereditary info. is in the form of DNA (deoxyribonucleic acid).
There are two types of reproduction: Sexual reproduction Asexual reproduction
4. Evolution
Evolution is the process of change in a population over a period of time.
Scientists suggest that this process occurs due to natural selection (the process by which organisms with favorable variations reproduce at higher rates than those without such variations).
There is both microevolution and macroevolution.
5. Interdependence of Organisms
Ecology studies the interactions of organisms with each other and their environments.
6. Matter, Energy, and Organization
Living things are highly organized structures that must be maintained in their orderly state by a constant supply of energy. How organisms obtain, use, and transfer energy is a major portion of the study of biology.
Organisms obtain their energy by either being heterotrophs or autotrophs.