Life sciences

The life sciences comprise the fields of science that involve the scientific study of living organisms – such as microorganisms, plants, animals, and human beings – as well as related considerations like bioethics. While biology remains the centerpiece of the life sciences, technological advances in molecular biology and biotechnology have led to a burgeoning of specializations and interdisciplinary fields.[1]

Some life sciences focus on a specific type of life. For example, zoology is the study of animals, while botany is the study of plants. Other life sciences focus on aspects common to all or many life forms, such as anatomy and genetics. Yet other fields are interested in technological advances involving living things, such as bio-engineering. Another major, though more specific, branch of life sciences involves understanding the mind – neuroscience.

The life sciences are helpful in improving the quality and standard of life. They have applications in health, agriculture, medicine, and the pharmaceutical and food science industries.

There is considerable overlap between many of the topics of study in the life sciences.

Topics of study Affective neuroscience 
Brain parts involved with a fear amygdala hijack from optical stimulusMain article: Affective neuroscience
Affective neuroscience is the study of the neural mechanisms of emotion. This interdisciplinary field combines neuroscience with the psychological study of personality, emotion, and mood.[2]

Anatomy 
Sagittal MRI scan of the headMain article: Anatomy
Anatomy is the study of the body plan of animals, divided into gross (or macroscopic) anatomy and microscopic anatomy including histology (the study of tissues) and cytology (the study of cells), and with facets including comparative anatomy and comparative embryology.[3] Human anatomy is important in medicine. The history of anatomy shows rising understanding of the organs and structures of the human body, and improving methods from dissection of cadavers to medical imaging technologies including X-ray, ultrasound, and magnetic resonance imaging.

Astrobiology Main article: Astrobiology
 
The NASA Kepler mission, launched in March 2009, searches for extrasolar planetsAstrobiology is the study of the origin, evolution, distribution, and future of life in the universe: extraterrestrial life and life on Earth, and the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for prebiotic chemistry, and research into the origins of life.[4][5] Astrobiology makes use of physics, chemistry, astronomy, biology, molecular biology, ecology, planetary science, geography, and geology.[6][7]

Biochemistry Main article: Biochemistry
 
A schematic of hemoglobin. The red and blue ribbons represent the protein globin; the green structures are the heme groups.Biochemistry is the study of chemical processes in the cells of living organisms.[8] By controlling information flow through biochemical signaling and the flow of chemical energy through metabolism, these processes give rise to the complexity of life. Closely related to molecular biology, it contributes to life sciences from botany to medicine.[9] It deals with macromolecules, such as proteins, nucleic acids, carbohydrates and lipids, as well as smaller molecules such as amino acids.

Biocomputers Main article: Biocomputers
Biocomputers use systems of biologically derived molecules, such as DNA and proteins, to perform computational calculations involving storing, retrieving, and processing data. The development of biocomputers has been made possible by the expanding new science of nanobiotechnology.

Biocontrol Main article: Biocontrol
 
Encarsia formosa was one of the first biological control agents developed.Biological control (known as biological control) is a bioeffector-method of controlling pests (including insects, mites, weeds and plant diseases) using other living organisms.[10]

Biodynamics Main article: Biodynamics
Biodynamic agriculture is a method of organic farming originally developed by Rudolf Steiner that employs what proponents describe as "a holistic understanding of agricultural processes".[11]:145 One of the first sustainable agriculture movements,[12][13][14]

Bioinformatics Main article: Bioinformatics
Bioinformatics is an interdisciplinary scientific field that develops methods for storing, retrieving, organizing and analyzing biological data. A major activity in bioinformatics is to develop software tools to generate useful biological knowledge.

Biology Main article: Biology
Biology is the parent natural science of all the life sciences. It involves the study of all aspects of organisms, including their structure, function, growth, evolution, distribution, and taxonomy,[15] with many branches and subdisciplines. It recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species. All organisms survive by consuming and transforming energy and by regulating their internal environment.[16]

Biomaterials Main article: Biomaterials
A biomaterial is any matter, surface, or construct that interacts with biological systems. As a science, biomaterials is about fifty years old. The study of biomaterials is called biomaterials science. It has experienced steady and strong growth over its history, with many companies investing large amounts of money into the development of new products. Biomaterials science encompasses elements of medicine, biology, chemistry, tissue engineering and materials science.

Biomechanics Main article: Biomechanics
Biomechanics is the study of the structure and function of biological systems such as humans, animals, plants, organs, and cells[17] by means of the methods of mechanics.[18]

Biomedical science Main article: Biomedical science
Healthcare science, also known as biomedical science, is a set of applied sciences applying portions of natural science or formal science, or both, to develop knowledge, interventions, or technology of use in healthcare or public health.[19] Such disciplines as medical microbiology, clinical virology, clinical epidemiology, genetic epidemiology, and biomedical engineering are medical sciences. Explaining physiological mechanisms operating in pathological processes, however, pathophysiology can be regarded as basic science.

Biomedicine Main article: Biomedicine
Biomedicine, or Medical biology, is a branch of medical science that applies biological and other natural-science principles to clinical practice.[20] Biomedicine is related to the ability of humans to cope with environmental stress. The branch especially applies to biology and physiology.[21] Biomedicine also can relate to many other categories in health and biological related fields.

Biomonitoring Main article: Biomonitoring
In analytical chemistry, biomonitoring is the measurement of the body burden[22] of toxic chemical compounds, elements, or their metabolites, in biological substances.[23][24] Often, these measurements are done in blood and urine.[25]

The two best established biomonitoring programs in representative samples of the general population are those of the United States and Germany, although population-based programs exist in a few other countries.[26] In 2001, the U.S. Centers for Disease Control and Prevention (CDC) began to publish its biennial National Report on Human Exposure to Environmental Chemicals, which reports a statistically representative sample of the U.S. population.[27] The Environmental Working Group has also conducted biomonitoring studies.[28]

Biophysics Main article: Biophysics
 
Photosynthetic reaction center.Biophysics is an interdisciplinary science using methods of, and theories from, physics to study biological systems.[29] Biophysics spans all levels of biological organization, from the molecular scale to whole organisms and ecosystems. Biophysical research shares significant overlap with biochemistry, nanotechnology, bioengineering, agrophysics, and systems biology. It has been suggested as a bridge between biology and physics.

Biopolymers Main article: Biopolymer
Biopolymers are polymers produced by living organisms; in other words, they are polymeric biomolecules. Since they are polymers, biopolymers contain monomeric units that are covalently bonded to form larger structures. There are three main classes of biopolymers, classified according to the monomeric units used and the structure of the biopolymer formed: polynucleotides (RNA and DNA), which are long polymers composed of 13 or more nucleotide monomers; polypeptides, which are short polymers of amino acids; and polysaccharides, which are often linear bonded polymeric carbohydrate structures.[30][31][32][33]

Biotechnology Main article: Biotechnology
Biotechnology is the use of living systems and organisms to develop or make useful products, or "any technological application that uses biological systems, living organisms or derivatives thereof, to make or modify products or processes for specific use" (UN Convention on Biological Diversity, Art. 2).[34] Depending on the tools and applications, it often overlaps with the (related) fields of bioengineering and biomedical engineering.

For thousands of years, humankind has used biotechnology in agriculture, food production, and medicine.[35] The term itself is largely believed to have been coined in 1919 by Hungarian engineer Károly Ereky. In the late 20th and early 21st century, biotechnology has expanded to include new and diverse sciences such as genomics, recombinant gene technologies, applied immunology, and development of pharmaceutical therapies and diagnostic tests.[36]

Botany Main article: Botany
 Plants move or grow in a particular direction in response to external stimuli. Here the Venus fly trap, Dionaea muscipula, shows dramatic touch sensitivity.Botany is the science of plant life. It includes the study of fungi and algae, studied by mycologists and phycologists respectively, as well as true plants. Botany originated as herbalism with the efforts of early humans to identify and grow edible, medicinal and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens and later botanical gardens supported early work in plant taxonomy. Botany includes plant morphology, growth, reproduction, biochemistry and primary metabolism, chemical products, development, diseases, evolutionary relationships and classification. and more recently molecular genetics and epigenetics. Botanical research helps to develop staple foods and textiles, horticulture, agriculture and forestry, plant propagation, breeding and genetic modification, the synthesis of chemicals and raw materials for construction and energy production, environmental management, and the maintenance of biodiversity.[citation needed]

Cell biology Main article: Cell biology
Cell biology studies cells – their physiology, structure, organelles, interactions, life cycle, division and death, both on a microscopic and molecular level. Research encompasses the diversity of single-celled organisms like bacteria and protozoa, and specialized cells in multicellular organisms such as humans, plants, and sponges. Cell biology is fundamental to all biological sciences, especially molecular biology cancer research, and developmental biology.

Cognitive neuroscience Main article: Cognitive neuroscience
Cognitive neuroscience is an academic field concerned with the scientific study of biological substrates underlying cognition,[37] with a specific focus on the neural substrates of mental processes. It addresses the questions of how psychological/cognitive functions are produced by the brain. Cognitive neuroscience is a branch of both psychology and neuroscience, overlapping with disciplines such as physiological psychology, cognitive psychology and neuropsychology.[38] Cognitive neuroscience relies upon theories in cognitive science coupled with evidence from neuropsychology, and computational modeling.[38]

Due to its multidisciplinary nature, cognitive neuroscientists may have various backgrounds. Other than the associated disciplines just mentioned, cognitive neuroscientists may have backgrounds in these disciplines: neurobiology, bioengineering, psychiatry, neurology, physics, computer science, linguistics, philosophy and mathematics.

Methods employed in cognitive neuroscience include experimental paradigms from psychophysics and cognitive psychology, functional neuroimaging, electrophysiology, cognitive genomics and behavioral genetics. Studies of patients with cognitive deficits due to brain lesions constitute an important aspect of cognitive neuroscience (see neuropsychology). Theoretical approaches include computational neuroscience and cognitive psychology.

Computational neuroscience Main article: Computational neuroscience
Computational neuroscience is the study of brain function in terms of the information processing properties of the structures that make up the nervous system.[39] It is an interdisciplinary science that links the diverse fields of neuroscience, cognitive science, and psychology with electrical engineering, computer science, mathematics, and physics.

Computational neuroscience is distinct from psychological connectionism and from learning theories of disciplines such as machine learning, neural networks, and computational learning theory in that it emphasizes descriptions of functional and biologically realistic neurons (and neural systems) and their physiology and dynamics. These models capture the essential features of the biological system at multiple spatial-temporal scales, from membrane currents, proteins, and chemical coupling to network oscillations, columnar and topographic architecture, and learning and memory.

These computational models are used to frame hypotheses that can be directly tested by biological and/or psychological experiments.

Conservation biology Main article: Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions.[40][41][42] It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.[43][44][45][46]

Developmental biology Main article: Developmental biology
Developmental biology is the study of the process by which organisms grow and develop, and is closely related to Ontogeny. Modern developmental biology studies the genetic control of cell growth, differentiation and morphogenesis, which is the process that gives rise to tissues, organs and anatomy, but also regeneration and aging.[47]

Ecology Main article: Ecology
 
Ecosystems often contain complex relationships between organisms, such as the mutual symbiosis between clownfish and tropical sea anemones.Ecology is the scientific study of interactions among organisms and their environment, such as the interactions organisms have with each other and with their abiotic environment. Topics of interest to ecologists include the diversity, distribution, amount (biomass), number (population) of organisms, as well as competition between them within and among ecosystems. Ecosystems are composed of dynamically interacting parts including organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and various niche construction activities, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits. The varieties of species, genes, and ecosystems is referred to as biodiversity and enhances certain ecosystem services. An understanding of how biodiversity affects ecological function is an important focus area in ecological studies. Ecologists seek to explain the successional development of ecosystems, and the abundance and distribution of organisms and biodiversity in the context of the environment. This, along with the movement of materials and energy through living communities of organisms, with their life processes, interactions and adaptations to the environment.

Ecology is an interdisciplinary field that includes biology and earth science. Evolutionary concepts on adaptation and natural selection became cornerstones of modern ecological theory in the late 19th century. As such, ecology is closely related to evolutionary biology, genetics, and ethology. Ecology is a human science as well. There are many practical applications of ecology in conservation biology, wetland management, natural resource management (agroecology, agriculture, forestry, agroforestry, fisheries), city planning (urban ecology), community health, economics, basic and applied science, and human social interaction (human ecology).

Organisms and resources compose ecosystems which, in turn, maintain biophysical feedback mechanisms that moderate processes acting on living (biotic) and nonliving (abiotic) components of the planet. Ecosystems sustain life-supporting functions and produce natural capital like biomass production (food, fuel, fiber and medicine), the regulation of climate, global biogeochemical cycles, water filtration, soil formation, erosion control, flood protection and many other natural features of scientific, historical, economic, or intrinsic value.

Environmental science Main article: Environmental science
Environmental science is a multidisciplinary academic field that integrates physical and biological sciences, (including but not limited to ecology, physics, chemistry, zoology, mineralogy, oceanology, limnology, soil science, geology, atmospheric science, and geography) to the study of the environment, and the solution of environmental problems.

Ethology Main article: Ethology
Ethology is the scientific and objective study of animal behaviour, and is a sub-topic of zoology. The focus of ethology is on animal behaviour under natural conditions,[48] as opposed to behaviourism, which focuses on behavioural response studies in a laboratory setting.

Evolutionary biology Main article: Evolutionary biology
Evolutionary biology is a sub-field of biology concerned with the study of the evolutionary processes that produced the diversity of life on Earth. Someone who studies evolutionary biology is known as an evolutionary biologist. Evolutionary biologists study the descent of species, and the origin of new species.

Evolutionary genetics Main article: Evolutionary genetics
The modern evolutionary synthesis is a 20th-century union of ideas from several biological specialties which provides a widely accepted account of evolution. It is also referred to as the new synthesis, the modern synthesis, the evolutionary synthesis, millennium synthesis and the neo-Darwinian synthesis.

The synthesis, produced between 1936 and 1947, reflects the consensus about how evolution proceeds.[49] The previous development of population genetics, between 1918 and 1932, was a stimulus, as it showed that Mendelian genetics was consistent with natural selection and gradual evolution. The synthesis is still, to a large extent, the current paradigm in evolutionary biology.[50]

The modern synthesis solved difficulties and confusions caused by the specialisation and poor communication between biologists in the early years of the 20th century. At its heart was the question of whether Mendelian genetics could be reconciled with gradual evolution by means of natural selection. A second issue was whether the broad-scale changes (macroevolution) seen by palaeontologists could be explained by changes seen in local populations (microevolution).

The synthesis included evidence from biologists, trained in genetics, who studied populations in the field and in the laboratory. These studies were crucial to evolutionary theory. The synthesis drew together ideas from several branches of biology which had become separated, particularly genetics, cytology, systematics, botany, morphology, ecology and paleontology.

Food science Main article: Food science
Food science is the applied science devoted to the study of food. Activities of food scientists include the development of new food products, design of processes to produce these foods, choice of packaging materials, shelf-life studies, study of the effects of food on the human body, sensory evaluation of products using panels or potential consumers, as well as microbiological and chemical testing.[51][52][53][54]

Genetics Main article: Genetics
 
Morgan's observation of sex-linked inheritance of a mutation causing white eyes in Drosophila led him to the hypothesis that genes are located upon chromosomes.Genetics, a discipline of biology, is the science of genes, heredity, and variation in living organisms.[55][56]

Genetics is the process of trait inheritance from parents to offspring, including the molecular structure and function of genes, gene behavior in the context of a cell or organism (e.g. dominance and epigenetics), gene distribution, and variation and change in populations. Given that genes are universal to living organisms, genetics can be applied to the study of all living systems, including bacteria, plants, animals, and humans. The observation that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding.[57] The modern science of genetics, seeking to understand this process, began with the work of Gregor Mendel in the mid-19th century.[58]

Mendel observed that organisms inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of a gene. A more modern working definition of a gene is a portion (or sequence) of DNA that codes for a known cellular function. This portion of DNA is variable, it may be small or large, have a few subregions or many subregions. The word "Gene" refers to portions of DNA that are required for a single cellular process or single function, more than the word refers to a single tangible item. A quick idiom that is often used (but not always true) is "one gene, one protein" meaning a singular gene codes for a singular protein type in a cell. Another analogy is that a "gene" is like a "sentence" and "nucleotides" are like "letters". A series of nucleotides can be put together without forming a gene (non-coding regions of DNA), like a string of letters can be put together without forming a sentence (babble). Nonetheless, all sentences must have letters, like all genes must have nucleotides.

The sequence of nucleotides in a gene is read and translated by a cell to produce a chain of amino acids which in turn spontaneously folds into a protein. The order of amino acids in a protein corresponds to the order of nucleotides in the gene. This relationship between nucleotide sequence and amino acid sequence is known as the genetic code. The amino acids in a protein determine how it folds into its unique three-dimensional shape, a structure that is ultimately responsible for the proteins function. Proteins carry out many of the functions needed for cells to live. A change to the DNA in a gene can change a protein's amino acid sequence, thereby changing its shape and function, rendering the protein ineffective or even malignant (see: sickle cell anemia). When a gene change occurs, it is referred to as a mutation.

Genetics acts in combination with an organism's environment and experiences to influence development and behavior. Genes may be activated or inactivated, as determined by a cell's or organism's intra- or extra-cellular environment. For example, while genes play a role in determining human height, an individual's nutrition and health during childhood also have a large effect.

Genomics Main article: Genomics
Genomics is a discipline in genetics that applies recombinant DNA, DNA sequencing methods, and bioinformatics to sequence, assemble, and analyze the function and structure of genomes (the complete set of DNA within a single cell of an organism).[59][60] The field includes efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping. The field also includes studies of intragenomic phenomena such as heterosis, epistasis, pleiotropy and other interactions between loci and alleles within the genome.[61] In contrast, the investigation of the roles and functions of single genes is a primary focus of molecular biology or genetics and is a common topic of modern medical and biological research. Research of single genes does not fall into the definition of genomics unless the aim of this genetic, pathway, and functional information analysis is to elucidate its effect on, place in, and response to the entire genome's networks.[62][63]

Health Sciences Main article: Health Sciences
The health sciences are a key branch of the life sciences, comprising all divisions of medicine and the medical sciences.

Immunogenetics Main article: Immunogenetics
Immunogenetics or immungenetics is the branch of medical research that explores the relationship between the immune system and genetics.

Autoimmune diseases, such as type 1 diabetes, are complex genetic traits which result from defects in the immune system. Identification of genes defining the immune defects may identify new target genes for therapeutic approaches. Alternatively, genetic variations can also help to define the immunological pathway leading to disease.

Immunology Main article: Immunology
Immunology is a branch of biomedical science that covers the study of all aspects of the immune system in all organisms.[64] It deals with the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders (autoimmune diseases, hypersensitivities, immune deficiency, transplant rejection); the physical, chemical and physiological characteristics of the components of the immune system in vitro, in situ, and in vivo. Immunology has applications in several disciplines of science, and as such is further divided.

Even before the concept of immunity (from immunis, Latin for "exempt") was developed, numerous early physicians characterized organs that would later prove to be part of the immune system. The key primary lymphoid organs of the immune system are the thymus and bone marrow, and secondary lymphatic tissues such as spleen, tonsils, lymph vessels, lymph nodes, adenoids, and skin and liver. When health conditions warrant, immune system organs including the thymus, spleen, portions of bone marrow, lymph nodes and secondary lymphatic tissues can be surgically excised for examination while patients are still alive.

Many components of the immune system are actually cellular in nature and not associated with any specific organ but rather are embedded or circulating in various tissues located throughout the body.

Immunotherapy Main article: Immunotherapy
Immunotherapy is a medical term defined as the "treatment of disease by inducing, enhancing, or suppressing an immune response".[65] Immunotherapies designed to elicit or amplify an immune response are classified as activation immunotherapies, while immunotherapies that reduce or suppress are classified as suppression immunotherapies.

Kinesiology Main article: Kinesiology
Kinesiology, also known as human kinetics, is the scientific study of human movement. Kinesiology addresses physiological, mechanical, and psychological mechanisms. Applications of kinesiology to human health include: biomechanics and orthopedics; strength and conditioning; sport psychology; methods of rehabilitation, such as physical and occupational therapy; and sport and exercise.[66] Individuals who have earned degrees in kinesiology can work in research, the fitness industry, clinical settings, and in industrial environments.[67] Studies of human and animal motion include measures from motion tracking systems, electrophysiology of muscle and brain activity, various methods for monitoring physiological function, and other behavioral and cognitive research techniques.[68][69]

Marine biology 
Coral reefs form complex marine ecosystems with tremendous biodiversity.Main article: Marine biology
Marine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy. Marine biology differs from marine ecology as marine ecology is focused on how organisms interact with each other and the environment, and biology is the study of the organisms themselves.

A large proportion of all life on Earth exists in the ocean. Exactly how large the proportion is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world[70] covering about 71% of the Earth's surface. Because of its depth it contains about 300 times the habitable volume of the terrestrial habitats on Earth. The habitats studied in marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in surface tension between the ocean and atmosphere, to the depths of the oceanic trenches, sometimes 10,000 meters or more beneath the surface of the ocean. Specific habitats include coral reefs, kelp forests, seagrass meadows, the surrounds of seamounts and thermal vents, tidepools, muddy, sandy and rocky bottoms, and the open ocean (pelagic) zone, where solid objects are rare and the surface of the water is the only visible boundary. The organisms studied range from microscopic phytoplankton and zooplankton to huge cetaceans (whales) 30 meters (98 feet) in length.

Medical devices Main article: Medical device
A medical device is an instrument, apparatus, implant, in vitro reagent, or similar or related article that is used to diagnose, prevent, or treat disease or other conditions, and does not achieve its purposes through chemical action within or on the body (which would make it a drug).[71] Whereas medicinal products (also called pharmaceuticals) achieve their principal action by pharmacological, metabolic or immunological means, medical devices act by other means like physical, mechanical, or thermal means.

Medical devices vary greatly in complexity and application. Examples range from simple devices such as tongue depressors, medical thermometers, and disposable gloves to advanced devices such as computers which assist in the conduct of medical testing, implants, and prostheses. The design of medical devices constitutes a major segment of the field of biomedical engineering.

The global medical device market reached roughly 209 billion US Dollars in 2006.[72]

Medical imaging Main article: Medical imaging
 Parasagittal MRI of the head, with aliasing artifacts (nose and forehead appear at the back of the head)Medical imaging is the technique and process used to create images of the human body (or parts and function thereof) for clinical purposes (medical procedures seeking to reveal, diagnose, or examine disease) or medical science (including the study of normal anatomy and physiology). Although imaging of removed organs and tissues can be performed for medical reasons, such procedures are not usually referred to as medical imaging, but rather are a part of pathology.[73] Examples of medical imaging include:[74]

X-rays
CT scans
Ultrasound
MRI scan
Medical Social Work Main article: Medical social work
Medical social work is a sub-discipline of social work, also known as hospital social work. Medical social workers typically work in a hospital, skilled nursing facility or hospice, have a graduate degree in the field, and work with patients and their families in need of psychosocial help. Medical social workers assess the psychosocial functioning of patients and families and intervene as necessary. Interventions may include connecting patients and families to necessary resources and supports in the community; providing psychotherapy, supportive counselling, or grief counselling; or helping a patient to expand and strengthen their network of social supports.

Medical social workers typically work on an interdisciplinary team with professionals of other disciplines (such as medicine, nursing, physical, occupational, speech and recreational therapy).

Microbiology Main article: Microbiology
 
An agar plate streaked with microorganismsMicrobiology is the study of microscopic organisms, either unicellular (single cell), multicellular (cell colony), or acellular (lacking cells).[75] Microbiology encompasses numerous sub-disciplines including virology, mycology, parasitology, and bacteriology.

Molecular biology Main article: Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry. Molecular biology chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interactions between the different types of DNA, RNA and protein biosynthesis as well as learning how these interactions are regulated.

Neuroethology Main article: Neuroethology
Neuroethology is the evolutionary and comparative approach study of animal behavior and the understanding of an animal's nervous system. [76]

Neuroscience Main article: Neuroscience
 
Illustration from Gray's Anatomy (1918) of a lateral view of the human brain, featuring the hippocampus among other neuroanatomical featuresNeuroscience is a branch of biology that deals with the study of the nervous system.[77] Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics, medicine and allied disciplines, philosophy, physics, and psychology. It also exerts influence on other fields, such as neuroeducation[78] and neurolaw.

Oncology Main article: Oncology
Oncology is the study of medicine that deals with cancer, including a person's diagnosis and therapy of cancer.[79]

Optogenetics Main article: Optogenetics
Optogenetics is a neuromodulation technique employed in neuroscience that uses a combination of techniques from optics and genetics to control and monitor the activities of individual neurons in living tissue—even within freely-moving animals—and to precisely measure the effects of those manipulations in real-time.[80] The key reagents used in optogenetics are light-sensitive proteins. Spatially-precise neuronal control is achieved using optogenetic actuators like channelrhodopsin, halorhodopsin, and archaerhodopsin, while temporally-precise recordings can be made with the help of optogenetic sensors like Clomeleon, Mermaid, and SuperClomeleon.[81]

The earliest approaches were developed and applied in the lab of Gero Miesenböck,[82][83] now Waynflete Professor of Physiology at the University of Oxford,[84] and Richard Kramer and Ehud Isacoff at the University of California, Berkeley; these methods conferred light sensitivity but were never reported to be useful by other laboratories due to the multiple components these approaches required. A distinct single-component approach involving microbial opsin genes introduced in 2005 turned out to be widely applied, as described below. Optogenetics is known for the high spatial and temporal resolution that it provides in altering the activity of specific types of neurons within defined brain areas to control a subject's behavior.

Optometry Main article: Optometry
Optometry is a health care profession concerned with the health of the eyes and related structures, as well as vision, visual systems, and vision information processing in humans.

Parasitology Main article: Parasitology
 
Adult black fly (Simulium yahense) with (Onchocerca volvulus) emerging from the insect's antenna. The parasite is responsible for the disease known as river blindness in Africa.'Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question, but by their way of life. This means it forms a synthesis of other disciplines, and draws on techniques from fields such as cell biology, bioinformatics, biochemistry, molecular biology, immunology, genetics, evolution and ecology.

Pathology Main article: Pathology
Pathology is the precise study and diagnosis of disease. Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling. Pathologies (or pathoses) is synonymous with diseases. The suffix "path" is used to indicate a state of disease, and may be used to indicate psychological (e.g. psychopath) or physical disease (e.g. cardiomyopathy).[85] A physician practicing pathology is called a pathologist.

Pathology addresses four components of disease: cause/etiology, mechanisms of development (pathogenesis), structural alterations of cells (morphologic changes), and the consequences of changes (clinical manifestations).[86]

Pathology is further separated into divisions, based on either the system being studied (e.g. dermatopathology) or the focus of the examination (e.g. forensic pathology and determining the cause of death).

Pharmacogenomics Main article: Pharmacogenomics
Pharmacogenomics (a portmanteau of pharmacology and genomics) is the technology that analyses how genetic makeup affects an individual's response to drugs.[87] It deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity.[88]

Pharmaceutical sciences Main article: Pharmaceutical sciences
The pharmaceutical sciences are a group of interdisciplinary areas of study concerned with the design, action, delivery, disposition, inorganic, physical, biochemical and analytical biology (anatomy and physiology, biochemistry, cell biology, and molecular biology), epidemiology, statistics, chemometrics, mathematics, physics, and chemical engineering, and applies their principles to the study of drugs.

Pharmacology Main article: Pharmacology
 
A variety of topics involved with pharmacology, including neuropharmacology, renal pharmacology, human metabolism, intracellular metabolism, and intracellular regulationPharmacology is the branch of medicine and biology concerned with the study of drug action,[89] where a drug can be broadly defined as any man-made, natural, or endogenous (within the body) molecule which exerts a biochemical and/or physiological effect on the cell, tissue, organ, or organism. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.

Physiology Main article: Physiology
Physiology is the scientific study of function in living systems.[90] This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or Medicine, awarded since 1901 by the Royal Swedish Academy of Sciences.

Population dynamics Main article: Population dynamics
Population dynamics is the study of short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes. Population dynamics deals with the way populations are affected by birth and death rates, and by immigration and emigration, and studies topics such as ageing populations or population decline.

Proteomics Main article: Proteomics
Proteomics is the large-scale study of proteins, particularly their structures and functions.[91][92]

Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The proteome is the entire set of proteins,[93] produced or modified by an organism or system. This varies with time and distinct requirements, or stresses, that a cell or organism undergoes.

Psychiatric social work Psychiatric social work is one of the oldest mental health professions.[94] Workers provide mental health services to the community, including psychotherapy and diagnosing mental illness.[95]

Psychology Main article: Psychology
Psychology is an academic and applied discipline that involves the scientific study of mental functions and behaviors.[96][97] Psychology has the immediate goal of understanding individuals and groups by both establishing general principles and researching specific cases,[98][99] and by many accounts it ultimately aims to benefit society.[100][101] In this field, a professional practitioner or researcher is called a psychologist and can be classified as a social, behavioral, or cognitive scientist.

Sports science Main article: Sports science
Sport science is a discipline that studies the application of treatment and prevention of injuries related to sports medicine. The study of sport science traditionally incorporates areas of physiology, psychology, and biomechanics but also includes other topics such as nutrition and diet,

Sport scientists and performance consultants are growing in demand and employment numbers, with the ever-increasing focus within the sporting world on achieving the best results possible. Through the study of science and sport, researchers have developed a greater understanding on how the human body reacts to exercise, training, different environments and many other stimuli.

Structural biology Main article: Structural biology
Structural biology is a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules, especially proteins and nucleic acids, how they acquire the structures they have, and how alterations in their structures affect their function. This subject is of great interest to biologists because macromolecules carry out most of the functions of cells, and because it is only by coiling into specific three-dimensional shapes that they are able to perform these functions.

Biomolecules are too small to see in detail even with the most advanced light microscopes. The methods that structural biologists use to determine their structures generally involve measurements on vast numbers of identical molecules at the same time. Another approach that structural biologists take to understanding structure is bioinformatics to look for patterns among the diverse sequences that give rise to particular shapes.

Systems biology Main article: Systems biology
Systems biology is a biology-based inter-disciplinary field of study that focuses on complex interactions within biological systems, using a more holistic perspective (holism instead of the more traditional reductionism) approach to biological and biomedical research. Particularly from year 2000 onwards, the concept has been used widely in the biosciences in a variety of contexts. One of the outreaching aims of systems biology is to model and discover emergent properties, properties of cells, tissues and organisms functioning as a system whose theoretical description is only possible using techniques which fall under the remit of systems biology. These typically involve metabolic networks or cell signaling networks.[102]

Zoology Main article: Zoology
Zoology is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct. Sub-disciplines include Zoography, Comparative anatomy, Animal physiology, Behavioral ecology, Ethology, Invertebrate Zoology, Vertebrate Zoology and Comparative Zoology. Taxonomically oriented disciplines such as mammalogy, herpetology, ornithology and entomology identify and classify species and study aspects specific to those groups.

Scientific societies Federation of European Biochemical Societies (FEBS)
European Molecular Biology Organization (EMBO)
International Union of Biological Sciences (IUBS)
Life Sciences Switzerland