Biology, EUS-GEN
How do plants feed themselves? How did dogs evolve from wolves? What good is the appendix in humans, anyway? Such questions fall within the domain of biology, which seeks to understand living organisms and their vital processes (although the jury’s still out on what our appendixes are for). Biology’s diverse fields include botany, ecology, evolution, genetics, medicine, physiology, and zoology.
Biology Encyclopedia Articles By Title
eusocial species, any colonial animal species that lives in multigenerational family groups in which the vast majority......
eustachian tube, hollow structure that extends from the middle ear to the pharynx (throat). The eustachian tube......
evergreen, any plant that retains its leaves through the year and into the following growing season. Many tropical......
Light-producing, or bioluminescent, organisms occur across the spectrum of life—get it, spectrum? There are blinking......
evolution, theory in biology postulating that the various types of plants, animals, and other living things on......
- Introduction
- Fossils, Species, Adaptation
- Biogeography, Adaptation, Species
- Darwin, Natural Selection, Genetics
- Natural Selection, Genetics, Adaptation
- Theory, Cultural Impact, Science
- Intelligent Design, Criticism, Theory
- Natural Selection, Adaptation, Genetics
- Genetic Variation, Rate, Adaptation
- Gene Mutations
- Genetics, Variation, Adaptation
- Genetic Drift, Natural Selection, Adaptation
- Overdominance, Genetics, Adaptation
- Natural, Sexual, Artificial
- Sexual Selection, Natural Selection, Adaptation
- Species, Speciation, Adaptation
- Mechanical Isolation
- Adaptive Radiation, Species Diversity, Natural Selection
- Speciation, Genetics, Differentiation
- Convergent, Parallel, Adaptation
- Diversity, Extinction, Adaptation
- Reconstruction, History, Theory
- Species, Genetics, Trees
- Molecular, Genetics, Species
- Molecular Clock, DNA, Genetics
excretion, the process by which animals rid themselves of waste products and of the nitrogenous by-products of......
- Introduction
- Metabolic, Nonmetabolic, Waste
- Waste Disposal, Elimination, Excretory System
- Photosynthesis, Transpiration, Metabolism
- Waste Removal, Metabolism, Animals
- Metabolites, Waste, Urine
- Water, Salt, Balance
- Nephridia, Malpighian Tubules, Coelomocytes
- Mollusks, Renal Glands, Urine
- Malpighian Tubules, Insects, Waste
- Mammalian Urine, Sweat, Feces
- Amphibian Glands, Urea, & Osmoregulation
- Vertebrate, Kidney, Urea
exercise-induced pulmonary hemorrhage, disease condition in horses in which blood appears in the airways during......
exophthalmos, abnormal protrusion of one or both eyeballs. The most common cause for unilateral or bilateral exophthalmos......
exoskeleton, rigid or articulated envelope that supports and protects the soft tissues of certain animals. The......
extensor muscle, any of the muscles that increase the angle between members of a limb, as by straightening the......
external auditory canal, passageway that leads from the outside of the head to the tympanic membrane, or eardrum......
extinction, in biology, the dying out or extermination of a species. Extinction occurs when species are diminished......
eye colour, heritable phenotypic (observable) trait determined by pigmentation and light scattering in the iris......
eye disease, any of the diseases or disorders that affect the human eye. Some conditions that affect the eye are......
- Introduction
- Malposition, Lids, Treatment
- Conjunctivitis, Blepharitis, Keratitis
- Sclera Inflammation
- Uveal Tract Tumors
- Retinal Detachment, Symptoms, Treatment
- Optic Nerve, Vision Loss, Glaucoma
- Glaucoma, Causes, Treatment
- Ocular Injuries, Trauma, Prevention
- Arteriosclerosis, Hypertension, Vascular
- Night Blindness, Colour Defects
- Optical Aids, Treatment, Prevention
human eye, in humans, specialized sense organ capable of receiving visual images, which are then carried to the......
- Introduction
- Extraocular Muscles
- Uvea, Retina, Optic Nerve
- Retina, Optic Nerve, Vision
- Vision, Retina, Optics
- Eye Movements, Vision, Coordination
- Eye Movements, Vision, Anatomy
- Pupil, Iris, Retina
- Retina, Optics, Vision
- Retina, Rods, Cones
- Temporal Summation
- Retina, Optics, Vision
- Colour Vision, Retina, Optics
- Nervous Messages, Optics, Anatomy
- Vision, Perception, Anatomy
- Optics, Retina, Corpus Callosum
- The perception of depth
- Electrophysiology, Visual Centres
eyeball, spheroidal structure containing sense receptors for vision, found in all vertebrates and constructed much......
eyelid, movable tissue, consisting primarily of skin and muscle, that shields and protects the eyeball from mechanical......
Fabry’s disease, sex-linked hereditary disease in which a deficiency in the enzyme alpha-galactosidase A results......
facultative anaerobe, any organism that is able to grow either with or without free oxygen. Facultative anaerobes......
false pregnancy, disorder that may mimic many of the effects of pregnancy, including enlargement of the uterus,......
familial hypercholesterolemia, an inherited metabolic disease that is caused by deficiency of the LDL (low-density......
farmer’s lung, a pulmonary disorder that results from the development of hypersensitivity to inhaled dust from......
fascia, network of connective tissue that envelops and supports the various structures and organs of the body,......
fascioliasis, infection of humans and grass-grazing animals caused by the liver fluke Fasciola hepatica, a small......
fasciolopsiasis, infection of humans and swine by the trematode Fasciolopsis buski, a parasitic worm. Human and......
The cell is the most basic unit of life on Earth, and the development of the cell membrane (or plasma membrane)......
feces, solid bodily waste discharged from the large intestine through the anus during defecation. Feces are normally......
feedback, in biology, a response within a system (molecule, cell, organism, or population) that influences the......
feline distemper, viral disease of cats, kittens two to six months old being most susceptible. Highly contagious,......
feline leukemia, viral disease of cats, one of the most serious diseases affecting domestic cats and a few other......
feline respiratory disease, a complex of viral contagions of cats (including rhinotracheitis, pneumonitis, and......
fermentation, chemical process by which molecules such as glucose are broken down anaerobically. More broadly,......
fertility, ability of an individual or couple to reproduce through normal sexual activity. About 90 percent of......
fertility rate, average number of children born to women during their reproductive years. For the population in......
fertilization, union of a sperm nucleus, of paternal origin, with an egg nucleus, of maternal origin, to form the......
fetal alcohol syndrome (FAS), various congenital abnormalities in the newborn infant that are caused by the mother’s......
fetus, the unborn young of any vertebrate animal, particularly of a mammal, after it has attained the basic form......
fibroblast, the principal active cell of connective tissue. Fibroblasts are large, flat, elongated (spindle-shaped)......
fibroma, any benign tumour of fibrous tissue. Specific fibromas include nonossifying fibroma, found in the large......
fibromyalgia, chronic syndrome that is characterized by musculoskeletal pain, often at multiple anatomical sites,......
fibrosarcoma, rare malignant tumour of fibrous tissue most commonly found in middle-age adults and primarily occurring......
fibrous dysplasia, rare congenital developmental disorder beginning in childhood and characterized by replacement......
fight-or-flight response, response to an acute threat to survival that is marked by physical changes, including......
filariasis, a group of infectious disorders caused by threadlike nematodes of the superfamily Filarioidea that......
filovirus, any virus belonging to the family Filoviridae. Filoviruses have enveloped virions (virus particles)......
fingerprint, impression made by the papillary ridges on the ends of the fingers and thumbs. Fingerprints afford......
fire blight, plant disease, caused by the bacterium Erwinia amylovora, that can give infected plants a scorched......
fistula, abnormal duct or passageway between organs. Fistulas can form between various parts of the body, including......
flagellate, (subphylum Mastigophora), any of a group of protozoans, mostly uninucleate organisms, that possess,......
flagellum, hairlike structure that acts primarily as an organelle of locomotion in the cells of many living organisms.......
flatfoot, congenital or acquired flatness of the longitudinal arch of the foot. Usually associated with loss of......
flatulence, the presence of excessive amounts of gas in the stomach or intestine, which sometimes results in the......
flavivirus, any virus belonging to the family Flaviviridae. Flaviviruses have enveloped and spherical virions (virus......
flexor muscle, any of the muscles that decrease the angle between bones on two sides of a joint, as in bending......
fluid, in physiology, a water-based liquid that contains the ions and cells essential to body functions and transports......
fly agaric, (Amanita muscaria), poisonous mushroom in the family Amanitaceae (order Agaricales) found in forests,......
food allergy, immunological response to a food. Although the true prevalence of food allergy is unclear, studies......
food poisoning, acute gastrointestinal illness resulting from the consumption of foods containing one or more representatives......
foodborne illness, any sickness that is caused by the consumption of foods or beverages that are contaminated with......
foot-and-mouth disease (FMD), a highly contagious viral disease affecting practically all cloven-footed domesticated......
foraminiferan, any unicellular organism of the rhizopodan order Foraminiferida (formerly Foraminifera), characterized......
forebrain, region of the developing vertebrate brain; it includes the telencephalon, which contains the cerebral......
founder principle, in genetics, the principle whereby a daughter population or migrant population may differ in......
frailty, medical condition that occurs as a result of aging-associated declines in energy, strength, and function......
freckle, a small, brownish, well-circumscribed, stainlike spot on the skin occurring most frequently in red- or......
fructosuria, disturbance of fructose metabolism resulting from a hereditary disorder or intolerance. Normally,......
fruit, the fleshy or dry ripened ovary of a flowering plant, enclosing the seed or seeds. Thus, apricots, bananas,......
fruit spot, symptom of plant disease, usually caused by fungi and bacteria. A spot is a definite, localized area.......
Fröhlich’s syndrome, rare childhood metabolic disorder characterized by obesity, growth retardation, and retarded......
Fuligo, genus of true slime molds (class Myxomycetes; q.v.) whose large fruiting body (compound sporangia), 5 centimetres......
fungus, any of about 144,000 known species of organisms of the kingdom Fungi, which includes the yeasts, rusts,......
- Introduction
- Decomposers, Symbiosis, Ecosystems
- Reproduction, Nutrition, Decomposition
- Structure, Reproduction, Nutrition
- Sporophores, Spores, Reproduction
- Reproduction, Nutrition, Hyphae
- Nutrition, Saprotrophs, Mycorrhizae
- Saprotrophism, Decomposition, Nutrition
- Parasitism, Plants, Insects
- Parasites, Infections, Diseases
- Mycorrhiza, Symbiosis, Nutrients
- Predation, Parasitism, Saprotrophs
- Spores, Hyphae, Reproduction
- Reproduction, Spores, Hyphae
- Reproduction, Spores, Hyphae
- Decomposition, Symbiosis, Saprophytes
- Lichens, Symbiosis, Photosynthesis
- Symbiosis, Photosynthesis, Lichens
- Evolution, Phylogeny, Eukaryotes
- Classification, Types, Reproduction
- Annotated classification
fusarium wilt, widespread plant disease caused by many forms of the soil-inhabiting fungus Fusarium oxysporum.......
G protein-coupled receptor (GPCR), protein located in the cell membrane that binds extracellular substances and......
Gaia hypothesis, model of the Earth in which its living and nonliving parts are viewed as a complex interacting......
gait analysis, in biology and medicine, the study of locomotion, particularly patterns of limb movements. In humans,......
galactosemia, a hereditary defect in the metabolism of the sugar galactose, which is a constituent of lactose,......
gall, an abnormal, localized outgrowth or swelling of plant tissue caused by infection from bacteria, fungi, viruses,......
gallbladder, a muscular membranous sac that stores and concentrates bile, a fluid that is received from the liver......
gamete, sex, or reproductive, cell containing only one set of dissimilar chromosomes, or half the genetic material......
gametogenesis, in embryology, the process by which gametes, or germ cells, are produced in an organism. The formation......
gametophyte, in plants and certain algae, the sexual phase (or an individual representing the phase) in the alternation......
ganglion, dense group of nerve-cell bodies present in most animals above the level of cnidarians. In flatworms......
gangrene, localized death of animal soft tissue, caused by prolonged interruption of the blood supply that may......
gasteromycetes, name often given to a subgroup of fungi consisting of more than 700 species in the phylum Basidiomycota......
gastric gland, any of the branched tubules in the inner lining of the stomach that secrete gastric juice and protective......
gastritis, acute or chronic inflammation of the mucosal layers of the stomach. Acute gastritis may be caused by......
gastrocnemius muscle, large posterior muscle of the calf of the leg. It originates at the back of the femur (thighbone)......
gastroenteritis, acute infectious syndrome of the stomach lining and the intestine. It is characterized by diarrhea,......
gastrointestinal tract, pathway by which food enters the body and solid wastes are expelled. The gastrointestinal......
Gaucher disease, rare inherited metabolic disorder characterized by anemia, mental and neurologic impairment, yellowish......
gender dysphoria (GD), formal diagnosis given by mental health professionals to people who experience distress......
gene, unit of hereditary information that occupies a fixed position (locus) on a chromosome. Genes achieve their......
gene flow, the introduction of genetic material (by interbreeding) from one population of a species to another,......
gene pool, sum of a population’s genetic material at a given time. The term typically is used in reference to a......
gene-for-gene coevolution, a specific form of reciprocal evolutionary change based on the idea that, if one member......
human genetic disease, any of the diseases and disorders that are caused by mutations in one or more genes of the......
- Introduction
- Sex Chromosome Abnormalities
- Autosomal Dominant, Inheritance, Genes
- Sex-Linked Inheritance
- Cancer Genetics, Mutations, Oncogenes
- Environmental Agents, Mutations, Diagnosis
- UV Radiation, Causes, Symptoms
- Prevention, Diagnosis, Treatment
- Estimating Probability, Bayes' Theorem
- Prenatal Diagnosis
- Genetic Testing, Inheritance, Diagnosis
- Ethical Issues
genetic drift, a change in the gene pool of a small population that takes place strictly by chance. Genetic drift......
genetic epidemiology, the study of how genes and environmental factors influence human traits and human health......
genetics, study of heredity in general and of genes in particular. Genetics forms one of the central pillars of......
human genetics, study of the inheritance of characteristics by children from parents. Inheritance in humans does......