Some parts are missing, there might be other branches that haven't been stated. Even so, I hope that this will be of use to you. :)
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