DEFINITION:
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
Biology generally recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the synthesis and creation of new species. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to a stable and vital condition.
SUBJECTS:
Subdisciplines of biology are defined by the scale at which organisms are studied, the kinds of organisms studied, and the methods used to study them:
- Biochemistry examines the chemistry of life;
- Molecular biology studies the complex interactions among biological molecules;
- Botany studies the biology of plants;
- Cellular biology examines the basic building block of all life, the cell;
- Physiology examines the physical and chemical functions of tissues, organs, and organ systems of an organism;
- Evolutionary biology examines the processes that produced the diversity of life; and ecology examines how organisms interact in their environment.
Science is a methodology for learning about the world.
It involves the application of knowledge. The scientific method deals with systematic investigation, reproducible results, the formation and testing of hypotheses, and reasoning:
- induction (specific data is used to develop a generalized observation or conclusion) and
- deduction (general information leads to specific conclusion).
Most reasoning in science is done through induction.
Science as we now know it arose as a discipline in the 17th century.
∙ Living things are composed of matter structured in an orderly way where simple molecules are ordered together into much larger macromolecules.
All organisms Grow, Respire, Interact, Move, Need Nutrients, Excrete (Waste), Reproduce and Die.
∙ Living things are sensitive, meaning they are able to respond to stimuli.
∙ Living things are able to grow, develop, and reproduce.
∙ Living things are able to adapt over time by the process of natural selection.
∙ All known living things use the hereditary molecule, DNA.
∙ Internal functions are coordinated and regulated so that the internal environment of a living thing is relatively constant, referred to as homeostasis. Living things are organized in the microscopic level from atoms up to cells. Atoms are arranged into molecules, then into macromolecules, which make up organelles, which work together to form cells.
Beyond this, cells are organized in higher levels to form entire multicellular organisms: