Anatomy – study of form in animals, plants and other organisms, or specifically in humans. Simply, the study of internal structure of living organisms.
Physiology – study of the internal workings of organisms and the functions of anatomical structures.
Comparative anatomy – the study of evolution of species through similarities and differences in their anatomy.
Gross anatomy – study of anatomy at the macroscopic level
Histology – also known as microscopic anatomy or microanatomy, the branch of biology which studies the microscopic anatomy of biological tissues.
Virophysics – study of mechanics and dynamics driving the interactions between virus and cells.
Biotechnology – new and sometimes controversial branch of biology that studies the manipulation of living matter, including genetic modification and synthetic biology.
Bioinformatics – use of information technology for the study, collection, and storage of genomic and other biological data.
Bioengineering – study of biology through the means of engineering with an emphasis on applied knowledge and especially related to biotechnology.
Synthetic biology – research integrating biology and engineering; construction of biological functions not found in nature.
Economic botany – study of relationship between people and plants, including the practical uses of plants
Ethnobotany – study of a region's plants and their usage by people
Photobiology – scientific study of the interactions of light (technically, non-ionizing radiation) and living organisms. The field includes the study of photosynthesis, photomorphogenesis, visual processing, circadian rhythms, bioluminescence, and ultraviolet radiation effects.
Cell biology – study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell.
Histology – study of the anatomy of cells and tissues of plants and animals using microscopy.
Chronobiology – field of biology that examines periodic (cyclic) phenomena in living organisms and their adaptation to solar- and lunar-related rhythms.
Dendrochronology – study of tree rings, using them to date the exact year they were formed in order to analyze atmospheric conditions during different periods in natural history.
Developmental biology – study of the processes through which an organism forms, from zygote to full structure
Embryology – study of the development of embryo (from fecundation to birth).
Evolutionary developmental biology – field of biology that compares the developmental processes of different organisms to determine the ancestral relationship between them, and to discover how developmental processes evolved.
Paleobiology – discipline which combines the methods and findings of the life sciences with the methods and findings of the earth science, paleontology.
Paleoanthropology – the study of fossil evidence for human evolution, mainly using remains from extinct hominin and other primate species to determine the morphological and behavioral changes in the human lineage, as well as the environment in which human evolution occurred.
Paleontology – study of fossils and sometimes geographic evidence of prehistoric life.
Paleopathology – the study of pathogenic conditions observable in bones or mummified soft tissue, and on nutritional disorders, variation in stature or morphology of bones over time, evidence of physical trauma, or evidence of occupationally derived biomechanic stress.
Molecular genetics – study of the bimolecular mechanisms behind the structure and function of DNA
Quantitative genetics – study of phenotypes that vary continuously (in characters such as height or mass)—as opposed to discretely identifiable phenotypes and gene-products (such as eye-colour, or the presence of a particular biochemical).
Marine biology – study of ocean ecosystems, plants, animals, and other living beings.
Microbiology – study of microscopic organisms (microorganisms) and their interactions with other living things.
Cognitive neuroscience – study of biological substrates underlying cognition, with a focus on the neural substrates of mental processes.
Computational neuroscience – study of the information processing functions of the nervous system, and the use of digital computers to study the nervous system.
Developmental neuroscience – study of the cellular basis of brain development and addresses the underlying mechanisms.
Molecular neuroscience – studies the biology of the nervous system with molecular biology, molecular genetics, protein chemistry and related methodologies.
Neuroanatomy – study of the anatomy of nervous tissue and neural structures of the nervous system.
Neuroendocrinology – studies the interaction between the nervous system and the endocrine system, that is how the brain regulates the hormonal activity in the body.
Neuroethology – study of animal behavior and its underlying mechanistic control by the nervous system.
Neuroimmunology – study of the nervous system, and immunology, the study of the immune system.
Neuropharmacology – study of how drugs affect cellular function in the nervous system.
Neurophysiology – study of the function (as opposed to structure) of the nervous system.
Systems biology – computational modeling of biological systems.
Zoology – study of animals, including classification, physiology, development, and behavior. Subbranches include:
Arthropodology – biological discipline concerned with the study of arthropods, a phylum of animals that include the insects, arachnids, crustaceans and others that are characterized by the possession of jointed limbs.
Acarology – study of the taxon of arachnids that contains mites and ticks.
Arachnology – scientific study of spiders and related animals such as scorpions, pseudoscorpions, harvestmen, collectively called arachnids.
Myriapodology – study of centipedes, millipedes, and other myriapods.
Ethology – scientific study of animal behavior, usually with a focus on behavior under natural conditions.
Helminthology – study of worms, especially parasitic worms.
Herpetology – study of amphibians (including frogs, toads, salamanders, newts, and gymnophiona) and reptiles (including snakes, lizards, amphisbaenids, turtles, terrapins, tortoises, crocodilians, and the tuataras).
Batrachology – subdiscipline of herpetology concerned with the study of amphibians alone.
Ichthyology – study of fishes. This includes bony fishes (Osteichthyes), cartilaginous fishes (Chondrichthyes), and jawless fishes (Agnatha).
Malacology – branch of invertebrate zoology which deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods.
Mammalogy – study of mammals, a class of vertebrates with characteristics such as homeothermic metabolism, fur, four-chambered hearts, and complex nervous systems. Mammalogy has also been known as "mastology," "theriology," and "therology." There are about 4,200 different species of animals which are considered mammals.
Cetology – branch of marine mammal science that studies the approximately eighty species of whales, dolphins, and porpoise in the scientific order Cetacea.
Human biology – interdisciplinary field studying the range of humans and human populations via biology/life sciences, anthropology/social sciences, applied/medical sciences
Biological anthropology – subfield of anthropology that studies the physical morphology, genetics and behavior of the human genus, other hominins and hominids across their evolutionary development
Human behavioral ecology – the study of behavioral adaptations (foraging, reproduction, ontogeny) from the evolutionary and ecologic perspectives (see behavioral ecology). It focuses on human adaptive responses (physiological, developmental, genetic) to environmental stresses.
Nematology – scientific discipline concerned with the study of nematodes, or roundworms.