Biology, EHL-FIB
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
Ehlers-Danlos syndrome (EDS), rare heritable disorder characterized primarily by great elasticity of the skin,......
ejaculatory duct, either of two hollow tubes, each formed by union of the ampulla of a ductus deferens (q.v.) and......
elastic fibre, any of the yellowish branching fibres composed primarily of the protein elastin, frequently arranged......
elbow, in human anatomy, hinge joint formed by the meeting of the humerus (bone of the upper arm) and the radius......
electrical shock, the perceptible and physical effect of an electrical current that enters the body. The shock......
electroreception, the ability to detect weak naturally occurring electrostatic fields in the environment. Electroreception......
embolism, obstruction of the flow of blood by an embolus, a particle or aggregate of substance that is abnormally......
embryo, the early developmental stage of an animal while it is in the egg or within the uterus of the mother. In......
embryology, the study of the formation and development of an embryo and fetus. Before widespread use of the microscope......
emergence, in evolutionary theory, the rise of a system that cannot be predicted or explained from antecedent conditions.......
emotional development, emergence of the experience, expression, understanding, and regulation of emotions from......
empyema, accumulation of pus in a cavity of the body, usually in the pleura, which are the serous membranes covering......
encephalitis, from Greek enkephalos (“brain”) and itis (“inflammation”), inflammation of the brain. Inflammation......
ENCODE, collaborative data-collection project begun in 2003 that aimed to inventory all the functional elements......
end-Triassic extinction, global extinction event occurring at the end of the Triassic Period (about 252 million......
endangered species, any species that is at risk of extinction because of a sudden rapid decrease in its population......
endemic species, in ecology, any species or other taxon whose geographic range or distribution is confined to a......
endocrine disruptor, any chemical that mimics or interferes with the normal actions of hormones in the body. Endocrine......
endocrine system, any of the systems found in animals for the production of hormones, substances that regulate......
human endocrine system, group of ductless glands that regulate body processes by secreting chemical substances......
endocrinology, medical discipline dealing with the role of hormones and other biochemical mediators in regulating......
endometriosis, disorder of the female reproductive system characterized by the growth of endometrial tissue (uterine......
endoplasmic reticulum (ER), in biology, a continuous membrane system that forms a series of flattened sacs within......
endosperm, tissue that surrounds and nourishes the embryo in the seeds of angiosperms (flowering plants). In some......
Enterobacter, (genus Enterobacter), any of a group of rod-shaped bacteria of the family Enterobacteriaceae. Enterobacter......
entomology, branch of zoology dealing with the scientific study of insects. The Greek word entomon, meaning “notched,”......
entropion, inward turning of the border (or margin) of the eyelid (usually the lower eyelids), occurring most often......
ependymal cell, type of neuronal support cell (neuroglia) that forms the epithelial lining of the ventricles (cavities)......
ephemeral, in botany, any short-lived plant, usually one that has one or more generations per year, growing only......
epicanthic fold, fold of skin across the inner corner of the eye (canthus). The epicanthic fold produces the eye......
epidemic, an occurrence of disease that is temporarily of high prevalence. An epidemic occurring over a wide geographical......
epidemiology, branch of medical science that studies the distribution of disease in human populations and the factors......
epidermis, in zoology, protective outermost portion of the skin. There are two layers of epidermis, the living......
epididymitis, inflammation of the epididymis, the cordlike structure that runs along the posterior of the testis......
epigenetics, the study of the chemical modification of specific genes or gene-associated proteins of an organism.......
epigenomics, the study of chemical changes that regulate the expression, or use, of the entire collection of DNA......
epilepsy, chronic neurological disorder characterized by sudden and recurrent seizures which are caused by an absence......
epithelium, in anatomy, layer of cells closely bound to one another to form continuous sheets covering surfaces......
Epperson v. State of Arkansas, case in which the U.S. Supreme Court on November 12, 1968, ruled (9–0) that an Arkansas......
Epstein-Barr virus (EBV), virus of the Herpesviridae family that is the major cause of acute infectious mononucleosis,......
equine encephalitis, severe viral disease of horses and mules, transmitted by mosquitoes. It sometimes affects......
equine infectious anemia (EIA), disease of horses that is caused by a non-oncogenic (non-cancer-causing) retrovirus.......
equine respiratory disease, a complex of infections of viral origin, including equine viral rhinopneumonitis (viral......
erector spinae, a deep muscle of the back; it arises from a tendon attached to the crest along the centre of the......
ergot, fungal disease of cereal grasses, especially rye, caused by species of the ascomycete fungus Claviceps.......
erysipelas, contagious infection of the skin and underlying tissue, caused by group A B-hemolytic streptococcus......
erysipelothrix infection, any of several infectious diseases caused by the widespread bacterium Erysipelothrix......
erythema, any abnormal redness of the skin. Erythema is caused by dilation and irritation of the superficial capillaries;......
erythrasma, a superficial skin infection marked by reddish brown scaly patches and attributed to the bacterium......
erythroblast, nucleated cell occurring in red marrow as a stage or stages in the development of the red blood cell,......
erythroblastosis fetalis, type of anemia in which the red blood cells (erythrocytes) of a fetus are destroyed in......
esophageal cancer, disease characterized by the abnormal growth of cells in the esophagus, the muscular tube connecting......
esophagus, relatively straight muscular tube through which food passes from the pharynx to the stomach. The esophagus......
essential tremor, disorder of the nervous system characterized by involuntary oscillating movements that typically......
estrogen, any of a group of hormones that primarily influence the female reproductive tract in its development,......
ethnobotany, systematic study of the botanical knowledge of a social group and its use of locally available plants......
ethology, the study of animal behaviour. Although many naturalists have studied aspects of animal behaviour through......
eubacterium, term formerly used to describe and differentiate any of a group of prokaryotic true bacteria from......
eugenics, the selection of desired heritable characteristics in order to improve future generations, typically......
Euglena, genus of more than 1,000 species of single-celled flagellated (i.e., having a whiplike appendage) microorganisms......
eukaryote, any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane......
Eurotiomycetes, class of fungi in the phylum Ascomycota (sac fungi) within the kingdom Fungi. The members of Eurotiomycetes......
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......
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. This article briefly describes the more......
- 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......
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,......