Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines.
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the world.
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of reasoning.
The Oxford English Dictionary says that scientific method is: "a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
The limits of the science, however, have always been difficult to determine, and as the scope of biology has shifted over the years, its subject areas have been changed and reorganized. Today biology is subdivided into hierarchies based on the molecule, the cell, the organism, and the population.
Molecular biology, which spans biophysics and biochemistry, has made the most fundamental contributions to modern biology. Much is now known about the structure and action of nucleic acids and protein, the key molecules of all living matter. The discovery of the mechanism of heredity was a major breakthrough in modern science. Another important advance was in understanding how molecules conduct metabolism, that is, how they process the energy needed to sustain life.
Cellular biology is closely linked with molecular biology. To understand the functions of the cell the basic structural unit of living matter cell biologists study, its components on the molecular level. Organismal biology, in turn, is related to cellular biology, because the life functions of multicellular organisms are governed by the activities and interactions of their cellular components. The study of organisms includes their growth and development (developmental biology) and how they function (physiology). Particularly important are investigations of the brain and nervous system (neurophysiology) and animal behavior (ethology).
Population biology became firmly established as a major subdivision of biological studies in the 1970s. Central to this field is evolutionary biology, in which the contributions of Charles Darwin have been fully appreciated after a long period of neglect. Population genetics, the study of gene changes in populations, and ecology, the study of populations in their natural habitats, have been established subject areas since the 1930s. These two fields were combined in the 1960s to form a rapidly developing new discipline often called, simply, population biology. Closely associated is a new development in animal-behavior studies called sociobiology, which focuses on the genetic contribution to social interactions among animal populations.
Biology also includes the study of humans at the molecular, cellular, and organismal levels. If the focus of investigation is the application of biological knowledge to human health, the study is often termed biomedicine. Human populations are by convention not considered within the province of biology; instead, they are the subject of anthropology and the various social sciences. The boundaries and subdivisions of biology, however, are as fluid today as they have always been, and further shifts may be expected.
Branches of Biology
Biology, the study of life, has many aspects to it and many specializations within this broad field. Below is an alphabetical list of many of the branches of biology.
Agriculture - study of producing crops from the land, with an emphasis on practical applications.
Anatomy - the study of the animal form, with an emphasis on human bodies.
Biochemistry - the study of the chemical reactions required for life to exist and function, usually a focus on the cellular level.
Bioengineering - the study of biology through the means of engineering with an emphasis on applied knowledge and especially related to biotechnology.
Bioinformatics - also classified as a branch of information technology (IT) it is the study, collection, and storage of genomic data.
Biomathematics or Mathematical Biology - the study of biological processes through mathematics, with an emphasis on modeling.
Biomechanics - often considered a branch of medicine, the study of the mechanics of living beings, with an emphasis on applied use through artificial limbs, etc.
Biophysics - the study of biological processes through physics, by applying the theories and methods traditionally used in the physical sciences.
Biotechnology - a new and sometimes controversial branch of biology that studies the manipulation of living matter, including genetic modification.
Botany - the study of plants
Cell Biology - the study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell.
Conservation Biology - the study of the preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife.
Cryobiology - the study of the effects of lower than normally preferred temperatures on living beings.
Developmental Biology - the study of the processes through which an organism develops, from zygote to full structure.
Ecology - the study of the ecosystem as a complete unit, with an emphasis on how species and groups of species interact with other living beings and non-living elements.
Entomology - the study of insects
Environmental Biology - the study of the natural world, as a whole or in a particular area, especially as affected by human activity.
Epidemiology - a major component of public health research, it is the study of factors affecting the health and illness of populations.
Ethology - the study of animal behavior.
Evolution or Evolutionary Biology - the study of the origin and decent of species over time.
Genetics - the study of genes and heredity.
Herpetology - the study of reptiles (and amphibians?)
Histology - The study of cells and tissue, a microscopic branch of anatomy.
Ichthyology - the study of fish
Macrobiology - the study of biology on the level of the macroscopic individual (plant, animal, or other living being) as a complete unit.
Mammology - the study of mammals
Marine Biology - the study of ocean ecosystems, plants, animals, and other living beings.
Medicine - the study of the human body in health and disease, with allopathic medicine focusing on alleviating or curing the body from states of disease.
Microbiology - the study of microscopic organisms (microorganisms) and their interactions with other living things.
Molecular Biology - the study of biology and biological functions at the molecular level, some cross over with biochemistry.
Mycology - the study of fungi
Neurobiology - the study of the nervous system, including anatomy, physiology, even pathology
Oceanography - the study of the ocean, including ocean life, environment, geography, weather, and other aspects influencing the ocean. See Marine Biology.
Ornithology - the study of birds
Paleontology - the study of fossils and sometimes geographic evidence of prehistoric life.
Pathobiology or pathology - the study of diseases, and the causes, processes, nature, and development of disease.
Parisitology - the study of parasites and parasitism
Pharmacology - the study and practical application of preparation, use, and effects of drugs and synthetic medicines.
Physiology - the study of the functioning of living organisms and the organs and parts of living organisms.
Phytopathology - the study of plant diseases
Pre-medicine - a college major that covers the general aspects of biology as well as specific classes relevant to the study of medicine.
Virology - the study of viruses and some other virus-like agents, usually considered part of microbiology or pathology.
Zoology - the study of animals and animal life, including classification, physiology, development, and behavior (See also Entomology, Ethology, Herpetology, Ichthyology, Mammology, Ornithology.
