Life Cycle, Processes & Properties, DOU-EWI
None of us are born looking exactly the way that we do today; this is because humans, like other species, undergo a series of changes as they mature and age, in accordance with their biological life cycle. This process can look very different across different species. In many simple organisms and in higher animals, the life cycle is completed within a single generation, while in most plants, the life cycle is multigenerational.
Life Cycle, Processes & Properties Encyclopedia Articles By Title
double fertilization
double fertilization, in flowering plant reproduction, the fusion of the egg and sperm and the simultaneous fusion......
double vision
double vision, perceiving of two images of a single object. Normal binocular vision results from the brain’s fusion......
dourine
dourine, venereal disease of horses, caused by the protozoan Trypanosoma equiperdum. The disease, which involves......
Down syndrome
Down syndrome, congenital disorder caused by the presence in the human genome of extra genetic material from chromosome......
Downy mildew
Downy mildew, disease of plants, especially in cool humid regions, caused by several funguslike organisms of the......
Driesch, Hans Adolf Eduard
Hans Adolf Eduard Driesch was a German experimental embryologist and philosopher who was the last great spokesman......
drowning
drowning, suffocation by immersion in a liquid, usually water. Water closing over the victim’s mouth and nose cuts......
drug abuse
drug abuse, the excessive, maladaptive, or addictive use of drugs for nonmedical purposes despite social, psychological,......
drug allergy
drug allergy, hypersensitivity reaction to therapeutic agents that occasionally occurs on subsequent exposure to......
drug overdose
drug overdose, ingestion or administration of a drug or drugs in an amount that exceeds recommended levels or quantities......
drug resistance
drug resistance, Property of a disease-causing organism that allows it to withstand drug therapy. In any population......
drupe
drupe, in botany, simple fleshy fruit that usually contains a single seed, such as the cherry, peach, and olive.......
Dry rot
symptom of fungal disease in plants, characterized by firm spongy to leathery or hard decay of stem (branch), trunk,......
Duchenne muscular dystrophy
Duchenne muscular dystrophy (DMD), rare X-linked form of muscular dystrophy that affects about 1 in 3,500 to 5,000......
Dupuytren’s contracture
Dupuytren’s contracture, flexion deformity of the hands caused by thickening of the fascia, or fibrous connective......
Dutch elm disease
Dutch elm disease, widespread fungoid killer of elms (Ulmus species) and certain other trees, first described in......
dwarfism
dwarfism, condition of growth retardation resulting in abnormally short adult stature and caused by a variety of......
dysarthria
dysarthria, motor speech disorder in which neurological damage impairs the ability of nerves to send messages to......
dysentery
dysentery, infectious disease characterized by inflammation of the intestine, abdominal pain, and diarrhea with......
dyslexia
dyslexia, an inability or pronounced difficulty to learn to read or spell, despite otherwise normal intellectual......
dysmenorrhea
dysmenorrhea, pain or painful cramps felt before or during menstruation. Dysmenorrhea may be primary or secondary.......
dyspareunia
dyspareunia, painful or difficult sexual intercourse in the female. Disorders are generally physical rather than......
dysphagia
dysphagia, difficulty or pain in swallowing, caused by lesions or stricture of the upper digestive tract, obstruction......
dysplasia
dysplasia, malformation of a bodily structure or tissue; the term most commonly denotes a malformation of bone.......
dystonia
dystonia, movement disorder characterized by the involuntary and repetitive contraction of muscle groups, resulting......
ear bone
ear bone, any of the three tiny bones in the middle ear of all mammals. These are the malleus, or hammer, the incus,......
ear disease
ear disease, any of the diseases or disorders that affect the human ear and hearing. Impaired hearing is, with......
ear squeeze
ear squeeze, effects of a difference in pressure between the internal ear spaces and the external ear canal. These......
ear, human
human ear, organ of hearing and equilibrium that detects and analyzes sound by transduction (or the conversion......
- Introduction
- Anatomy, Hearing, Balance
- Eardrum, Ossicles, Hearing
- Cochlea, Vestibule, Semicircular Canals
- Cochlea, Hearing, Balance
- Hearing, Cochlea, Organ of Corti
- Endolymph, Perilymph, Hearing
- Hearing, Anatomy, Physiology
- Sound Waves, Outer & Middle Ear
- Bone Conduction, Hearing, Vibration
- Cochlea, Hair Cells, Auditory Nerve
- Cochlear Nerve, Auditory Pathways
- Auditory Nervous System, Hearing, Sound
- Hearing Tests, Anatomy, Acoustics
- Balance, Vestibular, Physiology
earwax impaction
earwax impaction, filling of the external auditory canal with earwax, or cerumen. Normally the wax produced by......
eating disorders
eating disorders, atypical eating patterns, including anorexia nervosa, bulimia, compulsive overeating, and pica......
Ebola
Ebola, contagious disease caused by a virus of the family Filoviridae that is responsible for a severe and often......
ebullism
ebullism, formation of bubbles in the bodily fluids because of an extreme reduction in the surrounding pressure.......
Ecdysis
Ecdysis, the shedding of the outer body layer in some animals for growth or change in shape and body form. The......
echinococcosis
echinococcosis, formation of cysts, or hydatids, at the site of infestation by the larval form of Echinococcus......
ecological fallacy
ecological fallacy, in epidemiology, failure in reasoning that arises when an inference is made about an individual......
ectoderm
ectoderm, the outermost of the three germ layers, or masses of cells, which appears early in the development of......
ectopic pregnancy
ectopic pregnancy, condition in which the fertilized ovum (egg) has become imbedded outside the uterine cavity.......
Ectotherm
Ectotherm, any so-called cold-blooded animal—that is, any animal whose regulation of body temperature depends on......
ectropion
ectropion, outward turning of the border (or margin) of the eyelid (usually the lower eyelids). The condition most......
edema
edema, in medicine, an abnormal accumulation of watery fluid in the intercellular spaces of connective tissue.......
Egg
Egg, in biology, the female sex cell, or gamete. In botany, the egg is sometimes called a macrogamete. In zoology,......
Egg tooth
Egg tooth, tooth or toothlike structure used by the young of many egg-laying species to break the shell of the......
Ehlers-Danlos syndrome
Ehlers-Danlos syndrome (EDS), rare heritable disorder characterized primarily by great elasticity of the skin,......
ehrlichiosis
ehrlichiosis, any of a group of illnesses stemming from a tick-borne bacterial infection that affects humans and......
elbow injuries
elbow injuries, the common sprains, dislocations, and fractures caused by forced movement of the joint beyond its......
electrical shock
electrical shock, the perceptible and physical effect of an electrical current that enters the body. The shock......
Electroreception
Electroreception, the ability to detect weak naturally occurring electrostatic fields in the environment. Electroreception......
elephantiasis
elephantiasis, condition associated with the infectious diseases known collectively as filariasis. Elephantiasis......
embolism
embolism, obstruction of the flow of blood by an embolus, a particle or aggregate of substance that is abnormally......
embryo
embryo, the early developmental stage of an animal while it is in the egg or within the uterus of the mother. In......
embryology
embryology, the study of the formation and development of an embryo and fetus. Before widespread use of the microscope......
emotional development
emotional development, emergence of the experience, expression, understanding, and regulation of emotions from......
emphysema
emphysema, condition characterized by widespread destruction of the gas-exchanging tissues of the lungs, resulting......
empyema
empyema, accumulation of pus in a cavity of the body, usually in the pleura, which are the serous membranes covering......
enamel
enamel, in anatomy, the hardest tissue of the body, covering part or all of the crown of the tooth in mammals.......
encephalitis
encephalitis, from Greek enkephalos (“brain”) and itis (“inflammation”), inflammation of the brain. Inflammation......
Encephalitis lethargica
Encephalitis lethargica, form of encephalitis that emerged in the early 20th century. An encephalitis lethargica......
enchondroma
enchondroma, solitary benign cartilaginous tumour that occurs mostly in the shafts of bones of the hands and feet,......
endocarditis
endocarditis, inflammation of the heart lining, or endocardium. Endocarditis is caused by any of a number of microorganisms,......
endocrine disruptor
endocrine disruptor, any chemical that mimics or interferes with the normal actions of hormones in the body. Endocrine......
endoderm
endoderm, the innermost of the three germ layers, or masses of cells (lying within ectoderm and mesoderm), which......
endometriosis
endometriosis, disorder of the female reproductive system characterized by the growth of endometrial tissue (uterine......
endometritis
endometritis, inflammation of the endometrium, the mucous lining of the uterus. Endometritis is most commonly caused......
endosperm
endosperm, tissue that surrounds and nourishes the embryo in the seeds of angiosperms (flowering plants). In some......
Endotherm
Endotherm, so-called warm-blooded animals; that is, those that maintain a constant body temperature independent......
endotoxin
endotoxin, toxic substance bound to the bacterial cell wall and released when the bacterium ruptures or disintegrates.......
enteritis
enteritis, inflammation of the intestines (especially of the small intestine), caused by irritants, poisons, viral......
entropion
entropion, inward turning of the border (or margin) of the eyelid (usually the lower eyelids), occurring most often......
enuresis
enuresis, elimination disorder characterized by four factors: the repeated voluntary or involuntary voiding of......
ephebophilia
ephebophilia, the sexual preference of an adult for mid- to late adolescents, specifically those who have reached......
ephemeral
ephemeral, in botany, any short-lived plant, usually one that has one or more generations per year, growing only......
epicanthic fold
epicanthic fold, fold of skin across the inner corner of the eye (canthus). The epicanthic fold produces the eye......
epidemic
epidemic, an outbreak of disease that is temporarily of high prevalence, occurring in individuals within a specific......
epidemiology
epidemiology, branch of medical science that studies the distribution of disease in human populations and the factors......
epididymitis
epididymitis, inflammation of the epididymis, the cordlike structure that runs along the posterior of the testis......
epidural hematoma
epidural hematoma, a type of head injury involving bleeding into the space between the skull and the dura mater,......
epilepsy
epilepsy, chronic neurological disorder characterized by sudden and recurrent seizures which are caused by an absence......
epithelioma
epithelioma, an abnormal growth, or tumour, of the epithelium, the layer of tissue (such as the skin or mucous......
epitope
epitope, portion of a foreign protein, or antigen, that is capable of stimulating an immune response. An epitope......
equine encephalitis
equine encephalitis, severe viral disease of horses and mules, transmitted by mosquitoes. It sometimes affects......
equine infectious anemia
equine infectious anemia (EIA), disease of horses that is caused by a non-oncogenic (non-cancer-causing) retrovirus.......
equine respiratory disease
equine respiratory disease, a complex of infections of viral origin, including equine viral rhinopneumonitis (viral......
Ergot
Ergot, fungal disease of cereal grasses, especially rye, caused by species of the ascomycete fungus Claviceps.......
erysipelas
erysipelas, contagious infection of the skin and underlying tissue, caused by group A B-hemolytic streptococcus......
erysipelothrix infection
erysipelothrix infection, any of several infectious diseases caused by the widespread bacterium Erysipelothrix......
erythema
erythema, any abnormal redness of the skin. Erythema is caused by dilation and irritation of the superficial capillaries;......
erythrasma
erythrasma, a superficial skin infection marked by reddish brown scaly patches and attributed to the bacterium......
erythroblastosis fetalis
erythroblastosis fetalis, type of anemia in which the red blood cells (erythrocytes) of a fetus are destroyed in......
erythromelalgia
erythromelalgia , rare disease in which the blood vessels of the hands and feet go through spasms of dilation associated......
esophageal cancer
esophageal cancer, disease characterized by the abnormal growth of cells in the esophagus, the muscular tube connecting......
esophagus
esophagus, relatively straight muscular tube through which food passes from the pharynx to the stomach. The esophagus......
essential tremor
essential tremor, disorder of the nervous system characterized by involuntary oscillating movements that typically......
ethanol
ethanol, a member of a class of organic compounds that are given the general name alcohols; its molecular formula......
Eurasian Magpie: A True Bird Brain
There is a fair amount of superstition surrounding the Eurasian magpie (also called the common magpie), a bird......
Eusocial species
Eusocial species, any colonial animal species that lives in multigenerational family groups in which the vast majority......
eustachian tube
eustachian tube, hollow structure that extends from the middle ear to the pharynx (throat). The eustachian tube......
evergreen
evergreen, any plant that retains its leaves through the year and into the following growing season. Many tropical......
Everything’s Illuminated: 6 Bioluminescent Organisms
Light-producing, or bioluminescent, organisms occur across the spectrum of life—get it, spectrum? There are blinking......
Ewing tumour of bone
Ewing tumour of bone, common malignant tumour of bone that occurs mainly in Caucasian males under the age of 20.......