Biology is the branch of natural sciences that deals with the study of living organisms and their interactions with the environment. This discipline of science examines every possible aspect of living organisms. Biology studies the function, structure, growth, evolution, origin and also the distribution of living organisms. Biology gives detailed descriptions of organisms and classifies them according to their function and interactions with the environment as well as with each other. There are four fundamental principals that constitute the foundations of modern biology. First, is cell theory, second, is genetics, third is evolution and fourth is homeostasis. The separate field of biology came into existence in the nineteenth century when similar characteristics of organisms were recognized. Organism biology has now become a fundamental subject in schools and universities and millions of biological sciences journals are published annually. Organism biology term papers are typically written in APA writing style but other styles may also be used depending upon the requirements of word limit and other associated institutional requirements.

There are many sub-fields of biology due to the vast nature of the classifications of organism biology. Historically, biology was divided into three fields, first being botany (study of plants), second being zoology (study of animals) and third, being microbiology. At present, there are many subfields within these three fields of biology. Some of them are biochemistry (studies the chemistry of living organisms), molecular biology (deals with the complex interactions of biological molecule), and cell biology or cytology (studies all aspects of the living cells).