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