Biology

Bioaccumulation Bioaccumulation is the process by which chemicals build up in organisms over time; it affects wildlife and human health and is distinct from biomagnification and bioconcentration.

Biochemical cascade (signal transduction pathway) Biochemical cascade A biochemical cascade is a chain of molecular events that conveys an external stimulus into a specific cellular response through receptors, intermediates, amplification and regulat…

Biochemistry: the chemistry of living systems Biochemistry Biochemistry is the scientific study of the chemical processes and biomolecules that underpin life, linking molecular structure to cellular function and informing medicine, agricul…

Biodegradation: natural breakdown of materials by living organisms Biodegradation Biodegradation is the biological breakdown of materials by microorganisms. This article explains mechanisms, factors affecting rates, history, applications, and distinctions like c…

Biodiversity: the variety of life and why it matters Biodiversity An overview of biodiversity: definitions, levels and metrics, its value to nature and people, main threats, and common approaches to conservation and monitoring.

Biofilm: microbial communities and their roles Biofilm A biofilm is a structured community of microorganisms embedded in a self-produced matrix. This article explains composition, formation, examples, impacts, and approaches to control…

Biogeography: distribution of life, patterns, history and practical importance Biogeography Study of the distribution of organisms across space and time, including causes of patterns, historical change, and applications in ecology, evolution, and conservation.

Bioinformatics: computational analysis of biological data Bioinformatics Bioinformatics applies computing, statistics and biology to organize, analyze and interpret large biological datasets such as genomes, sequences and molecular measurements.

Biological classification: principles, ranks, history and modern methods Biological classification Overview of biological classification (taxonomy): aims, hierarchical ranks, historical roots, modern phylogenetic methods, naming rules, species concepts, and practical uses in sci…

Biological control (biocontrol): managing pests with natural enemies Biological control Biological control uses predators, parasitoids, pathogens and herbivores to reduce pest populations in agriculture, forestry and urban settings as part of integrated, sustainable p…

Biological half-life: definition, factors, measurement and applications Biological half-life Time required for a substance in a living organism to lose half its activity by metabolism or excretion; central to dosing, toxicology, and radiation protection.

Biological hazard (biohazard): definition, risks, containment, and symbol Biological hazard Biological hazard (biohazard): agents or materials from living organisms that can harm people, animals, or ecosystems; includes causes, symbol, containment, safety levels and dispo…

Biological pigment Natural molecules that give organisms color by absorbing or reflecting light; they play roles in photosynthesis, signaling, camouflage, UV protection and have many scientific and c…

Biological rhythms: cycles of life from circadian to annual Biological rhythms Biological rhythms are repetitive cycles in living organisms—daily, seasonal, tidal and more—driven by internal clocks and synchronized to the environment; they affect behavior, ph…

Biological species concept Definition and overview of the biological species concept, its history, mechanisms of reproductive isolation, limits, alternatives, and significance in evolution and taxonomy.

Biologist: scientists who study living organisms Biologist An overview of biologists: what they study, main subfields, methods, history, applications, and roles in research, medicine, conservation and industry.

Biology: the scientific study of life and living systems Biology Biology is the natural science that examines life, organisms, their structures, functions, origins, interactions, and evolution across scales from molecules to ecosystems.

Bioluminescence: biological light production in nature Bioluminescence Bioluminescence is the biochemical production of visible light by living organisms. This article summarizes mechanisms, taxonomic distribution, ecological roles, evolutionary origi…

Biomass: ecological definitions, measurement and energy uses Biomass Comprehensive overview of biomass as living organic matter and as a renewable resource: definitions, measurement methods, ecological role, conversion technologies, feedstocks, sust…

Biosemiotics: the study of sign processes in living systems Biosemiotics Biosemiotics studies how living organisms produce, transmit and interpret signs. It complements quantitative biology by treating meaning, communication and informational processes…

Biota: the living components of an environment Biota Biota denotes all living organisms in a particular place and time. The term is used across ecology, biogeography and paleontology to describe communities from microbes to plants, a…

Biotechnology: concepts, methods, and applications Biotechnology Overview of biotechnology: use of living systems to create products, principal techniques, historical development, applications in agriculture, medicine and industry, and societal…

Biotic (living components of ecosystems) Biotic Biotic describes living organisms—animals, plants, fungi and microorganisms—and their roles, interactions, and influence on ecosystems, biodiversity, and human activities.

Bioturbation: Reworking of Soils and Sediments by Living Organisms Bioturbation Bioturbation is the disturbance and reworking of soils and sediments by plants and animals. It alters physical structure, chemistry, ecology and the fossil record across terrestria…

Bipedalism: locomotion on two limbs in animals and humans Bipedalism Bipedalism is locomotion using two rear limbs. This article explains types, anatomy and biomechanics, evolutionary origins, examples, advantages, and important distinctions includi…

Bird flight: forms, anatomy, and ecological roles Bird flight An overview of how and why birds fly, covering wing anatomy, flight modes (flapping, hovering, soaring, diving), energetics, migration, evolution and notable distinctions.

Birth (parturition): process, types, and cultural significance Birth Birth is the biological process by which a new individual leaves an egg or its mother. This article explains types of birth, common terms, human stages, and the social and medical…

Bivalve (Bivalvia): two‑valved molluscs — overview, anatomy, ecology, uses Bivalve Bivalves are aquatic molluscs with two hinged shells. This article summarizes their anatomy, feeding, habitats, reproduction, evolution, ecological roles and human uses.

Black bread mold (Rhizopus stolonifer) Black bread mold An overview of Rhizopus stolonifer—its appearance, life cycle, ecology, effects on food and health, and methods for prevention and study.

Black hair: characteristics, biology, and cultural significance Black hair An overview of black hair: its appearance, pigmentation, biological basis, global distribution, care practices, and common misconceptions.

Urinary bladder: structure, function, control, and clinical significance Bladder The urinary bladder is a hollow, muscular organ that stores urine and coordinates its controlled release. This article covers anatomy, physiology, neural control, development, and…

Blood: composition, function, circulation, and medical significance Blood An overview of blood as a circulating fluid tissue: its components, transport roles, clotting and immune functions, circulation, clinical importance and basic history.

Blood cell: types, functions, production and clinical importance Blood cell Comprehensive overview of blood cells: red cells, white cells, and platelets; their structure, formation in bone marrow, roles in oxygen transport, immunity and clotting, clinical…

Blood plasma: composition, function, and medical uses Blood plasma Overview of blood plasma: its makeup, physiological roles, clinical preparation and therapies, and key distinctions such as plasma versus serum.

Blood sugar (blood glucose) Blood sugar Concentration of glucose in the bloodstream; its role in metabolism, how it is regulated, common disorders (hypo- and hyperglycemia), measurement, and relevance to diabetes.

Blood vessel: structure, function, and clinical significance Blood vessel Blood vessels are the tubular network that carries blood through the circulatory system. This article explains their types, structure, physiological roles, regulation, development,…

Blood–brain barrier A protective, selective barrier formed by brain capillaries that controls passage of substances between the bloodstream and central nervous system, with key roles in health, diseas…

Blubber (subcutaneous fat of marine mammals) Blubber Blubber is the thick, vascularised layer of fat beneath the skin of many marine mammals, providing insulation, energy storage, buoyancy and historical material for human use and st…

Body (organism): structure, parts, and meanings Body A body is the physical form of an organism — its cells, tissues and organs — and the term also appears in specialized senses (plant body, cell body, corpse) and in nonbiological ph…

Boletus: the pore-bearing mushrooms (porcini and relatives) Boletus Boletus is a genus of pore-bearing fungi noted for large edible species like porcini. Members form mycorrhizae with trees, have sponge-like pores under the cap, and have undergone…

Bolus: biological, medical and alimentary meanings Bolus A bolus is a compact mass — used in biology for ball-shaped forms, in medicine for a rapid large dose, and in digestion for the chewed food mass moved by peristalsis.

Bombycidae — the silkworm moth family Bombycidae Bombycidae are a family of moths that includes the domesticated silkworm (Bombyx mori), about 150 species in some 20–25 genera; they are central to sericulture and studied in genet…

Bombyliidae (bee flies): biology, life cycle, and ecological role Bombyliidae Bombyliidae, or bee flies, are a diverse family of nectar‑feeding, often bee‑mimicking flies. Adults pollinate flowers; larvae are commonly parasitoids. Many species and life histo…

Bone (vertebrate skeletal tissue) Bone A clear, concise overview of bone: its structure, development, functions (support, protection, blood formation), maintenance, and evolutionary and clinical notes.

Bone fracture A bone fracture is a partial or complete break in a bone caused by trauma, overuse, or disease; diagnosis, types, healing stages, treatments, complications, and prevention are cove…

Bone marrow: structure, function, and clinical significance Bone marrow Bone marrow is the soft tissue inside bones that produces blood cells, stores fat, and supports immune function; its health is vital for diagnosis and treatments such as transplant…

Borrelia: the spirochete genus behind Lyme disease and relapsing fever Borrelia Borrelia is a genus of spiral-shaped bacteria that includes species responsible for Lyme disease and relapsing fever. These zoonotic pathogens are transmitted mainly by ticks or, i…

Bowel Obstruction (Intestinal Obstruction) Bowel obstruction Bowel obstruction is a blockage that prevents normal passage through the small or large intestine. Causes, symptoms, diagnosis, treatment, complications, and historical development…