Life Cycle, Processes & Properties, EXC-GES
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
Excretion
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
exercise-induced pulmonary hemorrhage, disease condition in horses in which blood appears in the airways during......
exfoliative dermatitis
exfoliative dermatitis, generalized redness and scaling of the skin that usually arises as a complication of a......
exhibitionism
exhibitionism, derivation of sexual gratification through compulsive display of one’s genitals. Like voyeurism......
exophthalmos
exophthalmos, abnormal protrusion of one or both eyeballs. The most common cause for unilateral or bilateral exophthalmos......
exotoxin
exotoxin, a poisonous substance secreted by certain bacteria. In their purest form they are the most potent poisons......
external auditory canal
external auditory canal, passageway that leads from the outside of the head to the tympanic membrane, or eardrum......
eye colour
eye colour, heritable phenotypic (observable) trait determined by pigmentation and light scattering in the iris......
eye disease
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
eye, human
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
eyeball, spheroidal structure containing sense receptors for vision, found in all vertebrates and constructed much......
eyelid
eyelid, movable tissue, consisting primarily of skin and muscle, that shields and protects the eyeball from mechanical......
Eyespot
Eyespot, a heavily pigmented region in certain one-celled organisms that apparently functions in light reception.......
Fabry’s disease
Fabry’s disease, sex-linked hereditary disease in which a deficiency in the enzyme alpha-galactosidase A results......
Falling Far from the Tree: 7 Brilliant Ways Seeds and Fruits Are Dispersed
It’s tough for a little seed to make it in the big world. Not only must a seed land in a suitable place to grow,......
Fallot, tetralogy of
tetralogy of Fallot, combination of congenital heart defects characterized by hypoxic spells (which include difficulty......
false pregnancy
false pregnancy, disorder that may mimic many of the effects of pregnancy, including enlargement of the uterus,......
familial hypercholesterolemia
familial hypercholesterolemia, an inherited metabolic disease that is caused by deficiency of the LDL (low-density......
farmer’s lung
farmer’s lung, a pulmonary disorder that results from the development of hypersensitivity to inhaled dust from......
fascioliasis
fascioliasis, infection of humans and grass-grazing animals caused by the liver fluke Fasciola hepatica, a small......
fasciolopsiasis
fasciolopsiasis, infection of humans and swine by the trematode Fasciolopsis buski, a parasitic worm. Human and......
favism
favism, a hereditary disorder involving an allergic-like reaction to the broad, or fava, bean (Vicia faba). Susceptible......
feces
feces, solid bodily waste discharged from the large intestine through the anus during defecation. Feces are normally......
Feedback
Feedback, in biology, a response within a system (molecule, cell, organism, or population) that influences the......
Feeding behaviour
Feeding behaviour, any action of an animal that is directed toward the procurement of nutrients. The variety of......
feline distemper
feline distemper, viral disease of cats, kittens two to six months old being most susceptible. Highly contagious,......
feline leukemia
feline leukemia, viral disease of cats, one of the most serious diseases affecting domestic cats and a few other......
feline respiratory disease
feline respiratory disease, a complex of viral contagions of cats (including rhinotracheitis, pneumonitis, and......
fermentation
fermentation, chemical process by which molecules such as glucose are broken down anaerobically. More broadly,......
Fertilization
Fertilization, union of a sperm nucleus, of paternal origin, with an egg nucleus, of maternal origin, to form the......
fetal alcohol syndrome
fetal alcohol syndrome (FAS), various congenital abnormalities in the newborn infant that are caused by the mother’s......
fetus
fetus, the unborn young of any vertebrate animal, particularly of a mammal, after it has attained the basic form......
fever
fever, abnormally high body temperature. Fever is a characteristic of many different diseases. For example, although......
fiber, dietary
dietary fiber, Food material not digestible by the human small intestine and only partially digestible by the large......
fibrocystic disease of the breast
fibrocystic disease of the breast, noncancerous cysts (harmless swellings caused by fluid trapped in breast tissues)......
fibroma
fibroma, any benign tumour of fibrous tissue. Specific fibromas include nonossifying fibroma, found in the large......
fibromyalgia
fibromyalgia, chronic syndrome that is characterized by musculoskeletal pain, often at multiple anatomical sites,......
fibrosarcoma
fibrosarcoma, rare malignant tumour of fibrous tissue most commonly found in middle-age adults and primarily occurring......
fibrous dysplasia
fibrous dysplasia, rare congenital developmental disorder beginning in childhood and characterized by replacement......
filariasis
filariasis, a group of infectious disorders caused by threadlike nematodes of the superfamily Filarioidea that......
Filter feeding
Filter feeding, in zoology, a form of food procurement in which food particles or small organisms are randomly......
Fire blight
Fire blight, plant disease, caused by the bacterium Erwinia amylovora, that can give infected plants a scorched......
fish poisoning
fish poisoning, illness in humans resulting from the eating of varieties of poisonous fishes. Ciguatera poisoning......
fistula
fistula, abnormal duct or passageway between organs. Fistulas can form between various parts of the body, including......
flatfoot
flatfoot, congenital or acquired flatness of the longitudinal arch of the foot. Usually associated with loss of......
flatulence
flatulence, the presence of excessive amounts of gas in the stomach or intestine, which sometimes results in the......
Flavin
Flavin, any of a group of pale-yellow, greenly fluorescent biological pigments (biochromes) widely distributed......
Flavonoid
Flavonoid, any of a class of nonnitrogenous biological pigments extensively represented in plants. Flavonoids are......
flavor
flavor, attribute of a substance that is produced by the senses of smell, taste, and touch and is perceived within......
flaxseed
flaxseed, edible seeds harvested from flax (Linum usitatissimum) plants, used as a health food and as a source......
Flight
Flight, in animals, locomotion of either of two basic types—powered, or true, flight and gliding. Winged (true)......
fluoride deficiency
fluoride deficiency, condition in which fluoride is insufficient or is not utilized properly. Fluoride is a mineral......
fluorosis
fluorosis, chronic intoxication with fluorine (usually combined with some other element to form a fluoride) that......
folic acid deficiency anemia
folic acid deficiency anemia, type of anemia resulting from a deficient intake of the vitamin folic acid (folate).......
food allergy
food allergy, immunological response to a food. Although the true prevalence of food allergy is unclear, studies......
food poisoning
food poisoning, acute gastrointestinal illness resulting from the consumption of foods containing one or more representatives......
food pyramid
food pyramid, a visual representation (in the shape of a pyramid) of the optimal number of servings of food a person......
foodborne illness
foodborne illness, any sickness that is caused by the consumption of foods or beverages that are contaminated with......
foot-and-mouth disease
foot-and-mouth disease (FMD), a highly contagious viral disease affecting practically all cloven-footed domesticated......
Forbes’ disease
Forbes’ disease, rare hereditary disease in which the the metabolic breakdown of glycogen to the simple sugar glucose......
fracture
fracture, in pathology, a break in a bone caused by stress. Certain normal and pathological conditions may predispose......
fracture–dislocation
fracture–dislocation, a severe injury in which both fracture and dislocation take place simultaneously. Frequently,......
fragile-X syndrome
fragile-X syndrome, a chromosomal disorder associated with a fragile site on the end of the X chromosome. The major......
frailty
frailty, medical condition that occurs as a result of aging-associated declines in energy, strength, and function......
frigidity
frigidity, in psychology, the inability of a woman to attain orgasm during sexual intercourse. In popular, nonmedical......
Frisch, Karl von
Karl von Frisch was a zoologist whose studies of communication among bees added significantly to the knowledge......
frostbite
frostbite, a freezing of living tissue; frostbite occurs whenever heat loss from a tissue is sufficient to permit......
fructosuria
fructosuria, disturbance of fructose metabolism resulting from a hereditary disorder or intolerance. Normally,......
frugivore
frugivore, any animal that subsists totally or primarily on fruit. Although the diets of many animals include fruits,......
fruit
fruit, the fleshy or dry ripened ovary of a flowering plant, enclosing the seed or seeds. Thus, apricots, bananas,......
Fruit spot
Fruit spot, symptom of plant disease, usually caused by fungi and bacteria. A spot is a definite, localized area.......
Fröhlich’s syndrome
Fröhlich’s syndrome, rare childhood metabolic disorder characterized by obesity, growth retardation, and retarded......
fugue state
fugue state, loss of memory (amnesia), often temporary, in which affected individuals typically do not remember......
Fusarium wilt
Fusarium wilt, widespread plant disease caused by many forms of the soil-inhabiting fungus Fusarium oxysporum.......
galactorrhea
galactorrhea, excessive flow of milk from the breast, or lactation that is not associated with childbirth or nursing.......
galactosemia
galactosemia, a hereditary defect in the metabolism of the sugar galactose, which is a constituent of lactose,......
Gall
Gall, an abnormal, localized outgrowth or swelling of plant tissue caused by infection from bacteria, fungi, viruses,......
gallbladder
gallbladder, a muscular membranous sac that stores and concentrates bile, a fluid that is received from the liver......
gallbladder cancer
gallbladder cancer, disease characterized by the growth of malignant cells in the gallbladder. Gallbladder cancer......
gallstone
gallstone, concretion composed of crystalline substances (usually cholesterol, bile pigments, and calcium salts)......
gamete
gamete, sex, or reproductive, cell containing only one set of dissimilar chromosomes, being haploid. Male and female......
gametogenesis
gametogenesis, in embryology, the process by which gametes, or germ cells, are produced in an organism. The formation......
gametophyte
gametophyte, in plants and certain algae, the sexual phase (or an individual representing the phase) in the alternation......
ganglion cyst
ganglion cyst, saclike structure containing thick gelatinous fluid that appears on the top or underside of the......
gangrene
gangrene, localized death of animal soft tissue, caused by prolonged interruption of the blood supply that may......
gastritis
gastritis, acute or chronic inflammation of the mucosal layers of the stomach. Acute gastritis may be caused by......
gastroenteritis
gastroenteritis, acute infectious syndrome of the stomach lining and the intestine. It is characterized by diarrhea,......
gastroesophageal reflux disease
gastroesophageal reflux disease (GERD), relatively common digestive disorder characterized by frequent passage......
gastrointestinal tract
gastrointestinal tract, pathway by which food enters the body and solid wastes are expelled. The gastrointestinal......
gastrula
gastrula, early multicellular embryo, composed of two or more germinal layers of cells from which the various organs......
Gaucher disease
Gaucher disease, rare inherited metabolic disorder characterized by anemia, mental and neurologic impairment, yellowish......
gender dysphoria
gender dysphoria (GD), formal diagnosis given by mental health professionals to people who experience distress......
gene doping
gene doping, use of substances or techniques to manipulate cells or genes in order to improve athletic performance.......
genetic disease, human
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 epidemiology
genetic epidemiology, the study of how genes and environmental factors influence human traits and human health......
germ layer
germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting......
germ theory
germ theory, in medicine, is the scientific principle that infectious diseases are caused by specific microorganisms......
Germfree life
Germfree life, biological condition characterized by the complete absence of living microorganisms. Gnotobiology......
germination
germination, the sprouting of a seed, spore, or other reproductive body, usually after a period of dormancy. The......
Gestation
Gestation, in mammals, the time between conception and birth, during which the embryo or fetus is developing in......