Life Cycle, Processes & Properties, GES-HIV
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
gestational age
gestational age, length of time that a fetus grows inside the motherās uterus. Gestational age is related to the......
gestational diabetes mellitus
gestational diabetes mellitus, temporary condition in which blood sugar (glucose) levels increase during pregnancy......
gestational trophoblastic disease
gestational trophoblastic disease, any of a group of rare conditions in which tumours develop in the uterus from......
gigantism
gigantism, excessive growth in stature, well beyond the average for the individualās heredity and environmental......
gingivitis
gingivitis, inflammation of the gums (gingivae). Symptoms include tender, sometimes swollen, gums that bleed easily.......
glanders
glanders, infectious disease of primarily horses, but also mules and donkeys, that is caused by the bacterium Burkholderia......
glaucoma
glaucoma, disease caused by an increase in pressure within the eye as a result of blockage of the flow of aqueous......
glioblastoma
glioblastoma, rare form of aggressive brain tumor. Glioblastomas originate from neuroglia, or glial cells, a diverse......
glioma
glioma, a cancerous growth or tumor composed of cells derived from neuroglial tissue, the material that supports......
glossitis
glossitis, inflammation of the tongue characterized by loss of the surface papillae, a condition that gives the......
Gluconeogenesis
Gluconeogenesis, formation in living cells of glucose and other carbohydrates from other classes of compounds.......
glucose-6-phosphate dehydrogenase deficiency
glucose-6-phosphate dehydrogenase deficiency, hereditary metabolic defect characterized by an increased tendency......
glycogen storage disease
glycogen storage disease, any of a group of enzymatic deficiencies resulting in altered glycogen metabolism. They......
Glycogenesis
Glycogenesis, the formation of glycogen, the primary carbohydrate stored in the liver and muscle cells of animals,......
Glycogenolysis
Glycogenolysis, process by which glycogen, the primary carbohydrate stored in the liver and muscle cells of animals,......
glycolysis
glycolysis, sequence of 10 chemical reactions taking place in most cells that breaks down glucose, releasing energy......
Gnotobiosis
Gnotobiosis, (from the Greek meaning āknown lifeā), condition of life in which only known kinds of organisms are......
goitre
goitre, enlargement of the thyroid gland, resulting in a prominent swelling in the front of the neck. The normal......
gonad
gonad, in zoology, primary reproductive gland that produces reproductive cells (gametes). In males the gonads are......
gonorrhea
gonorrhea, sexually transmitted disease characterized principally by inflammation of the mucous membranes of the......
gout
gout, metabolic disorder characterized by recurrent acute attacks of severe inflammation in one or more of the......
graft-versus-host disease
graft-versus-host disease (GVHD), condition that occurs following a bone marrow transplant, in which cells in the......
Grandin, Temple
Temple Grandin is an American scientist and industrial designer whose own experience with autism funded her professional......
granuloma inguinale
granuloma inguinale, contagious sexually transmitted disease occurring predominantly in tropical areas and characterized......
granulomatosis and polyangiitis
granulomatosis and polyangiitis (GPA), uncommon disorder characterized by inflammation and degeneration of small......
granulomatous thyroiditis
granulomatous thyroiditis, inflammatory disease of the thyroid gland, of unknown but presumably viral origin. It......
Graves disease
Graves disease, endocrine disorder that is the most common cause of hyperthyroidism (excess secretion of thyroid......
Gray mold rot
Gray mold rot, disease of plants growing in humid areas that is caused by fungi in the genus Botrytis, usually......
Griffin, Donald Redfield
Donald Redfield Griffin was an American biophysicist and animal behaviorist known for his research in animal navigation,......
Growth
Growth, the increases in cell size and number that take place during the life history of an organism. Growth is......
Growth hormone
Growth hormone (GH), peptide hormone secreted by the anterior lobe of the pituitary gland. It stimulates the growth......
growth ring
growth ring, in a cross section of the stem of a woody plant, the increment of wood added during a single growth......
Guillain-BarrƩ syndrome
Guillain-BarrƩ syndrome, rare autoimmune condition of the peripheral nervous system. Guillain-BarrƩ syndrome can......
Guinea worm disease
Guinea worm disease, infection in humans caused by a parasite known as the guinea worm (Dracunculus medinensis).......
Gulf War syndrome
Gulf War syndrome, cluster of illnesses in veterans of the Persian Gulf War (1990ā91). Gulf War syndrome is characterized......
gum
gum, in anatomy, connective tissue covered with mucous membrane, attached to and surrounding the necks of the teeth......
gumma
gumma, soft, granulomatous, tumourlike mass, sometimes appearing during the late stages of syphilis, that occurs......
gynecomastia
gynecomastia, enlargement of the breasts in the male, usually because of hormone imbalance. The growth and development......
Haeckel, Ernst
Ernst Haeckel was a German zoologist and evolutionist who was a strong proponent of Darwinism and who proposed......
hairball
hairball, gastrointestinal obstruction occurring in cats and resulting from accumulation of swallowed hair; the......
Haller, Albrecht von
Albrecht von Haller was a Swiss biologist, the father of experimental physiology, who made prolific contributions......
hallucination
hallucination, the experience of perceiving objects or events that do not have an external source, such as hearing......
hamartoma
hamartoma, benign tumourlike growth made up of normal mature cells in abnormal number or distribution. While malignant......
hammertoe
hammertoe, deformity of the second, third, or fourth toe in which the toe is bent downward at the middle joint......
hapten
hapten, small molecule that stimulates the production of antibody molecules only when conjugated to a larger molecule,......
Hartnup disease
Hartnup disease, inborn metabolic disorder involving the amino acid tryptophan. Normally, one of the metabolic......
Hashimoto disease
Hashimoto disease, a noninfectious form of inflammation of the thyroid gland (thyroiditis). Hashimoto disease is......
Havana syndrome
Havana syndrome, claimed medical condition reported among U.S. diplomats and other government employees stationed......
hay fever
hay fever, seasonally recurrent bouts of sneezing, nasal congestion, and tearing and itching of the eyes caused......
head and neck cancer
head and neck cancer, any of a group of malignant diseases that originate variously in the oral cavity (including......
headache
headache, pain in various parts of the head. Headaches affect nearly everyone at some time in their life, recurrent......
hearing
hearing, in biology, physiological process of perceiving sound. See ear; mechanoreception; perception; sound...
heart attack
heart attack, the sudden interruption of blood flow to a portion of the heart muscle. Most heart attacks stem from......
heart block
heart block, lack of synchronization in the contractions of the upper and the lower chambers of the heartāthe atria......
heart disease
heart disease, broad term encompassing a range of disorders that affect the heartās structure and function. Heart......
heart failure
heart failure, chronic, progressive condition in which the heart is unable to generate sufficient cardiac output......
heart murmur
heart murmur, condition characterized by prolonged noises made by blood circulating through the heart. A heart......
Heart rot
Heart rot, any of several diseases of trees, root crops, and celery. Most trees are susceptible to heart-rotting......
heartworm disease
heartworm disease, parasitic disease, predominantly of dogs but also occurring in cats, that is caused by the nematode......
heatstroke
heatstroke, condition caused by continuous exposure to high temperatures and humidity for several hours. The term......
heaves
heaves, chronic disorder of the lungs of horses and cows, characterized by difficult breathing and wheezy cough.......
Heifer
Heifer, any young, female, domestic bovine that has not produced offspring. At birth, a female calf is often termed......
hematinic
hematinic, any vitamin or other substance that serves as a building block in the formation of blood components,......
hematoma
hematoma, pooling of blood in tissues or spaces outside the blood vessels that results when a vessel is cut or......
hematuria
hematuria, presence of blood in the urine, an indication of injury or disease of the kidney or some other structure......
hemiplegia
hemiplegia, paralysis of the muscles of the lower face, arm, and leg on one side of the body. The most common cause......
hemochromatosis
hemochromatosis, inborn metabolic defect characterized by an increased absorption of iron, which accumulates in......
hemoglobinopathy
hemoglobinopathy, any of a group of disorders caused by the presence of variant hemoglobin in the red blood cells.......
hemophilia
hemophilia, hereditary bleeding disorder caused by a deficiency of a substance necessary for blood clotting (coagulation).......
hemorrhage
hemorrhage, Escape of blood from blood vessels into surrounding tissue. When a vessel is injured, hemorrhage continues......
hemorrhoid
hemorrhoid, mass formed by distension of the network of veins under the mucous membrane that lines the anal channel......
hemothorax
hemothorax, collection of a bloody fluid in the pleural cavity, between the membrane lining the thoracic cage and......
hepatitis
hepatitis, inflammation of the liver that results from a variety of causes, both infectious and noninfectious.......
hepatitis B
hepatitis B, infectious disease of the liver, the causative agent of which is known as hepatitis B virus (HBV).......
hepatitis C
hepatitis C, infectious disease of the liver, the causative agent of which is known as hepatitis C virus (HCV).......
herbivore
herbivore, animal adapted to subsist solely on plant tissues. The herbivores range from insects (such as aphids)......
herd immunity
herd immunity, state in which a large proportion of a population is able to repel an infectious disease, thereby......
hereditary spherocytosis
hereditary spherocytosis, congenital blood disorder characterized by an enlarged spleen, spherical (rather than......
hermaphroditism
hermaphroditism, the condition of having both male and female reproductive organs. Hermaphroditic plantsāmost flowering......
hernia
hernia, protrusion of an organ or tissue from its normal cavity. The protrusion may extend outside the body or......
herniated disk
herniated disk, displacement of part of the rubbery centre, or nucleus, of a cartilaginous disk from between the......
heroin
heroin, highly addictive morphine derivative that makes up a large portion of the illicit traffic in narcotics.......
herpangina
herpangina, mild viral infection with sudden onset that is caused by several types of enteroviruses and seen most......
herpes simplex
herpes simplex, infection of either the skin or the genitalia caused by either of two strains of herpes simplex......
herpes zoster
herpes zoster, acute viral infection affecting the skin and nerves, characterized by groups of small blisters appearing......
Hersā disease
Hersā disease, hereditary deficiency of the liver enzyme glycogen phosphorylase, which governs the metabolic breakdown......
Hertwig, Oskar
Oskar Hertwig was a German embryologist and cytologist who was the first to recognize that the fusion of the nuclei......
heterospecific mating
heterospecific mating, mating in which the man and woman have incompatible blood types, such that the woman may......
Hibernation
Hibernation, a state of greatly reduced metabolic activity and lowered body temperature adopted by certain mammals......
hiccup
hiccup, spasmodic contraction of the diaphragm (the muscular partition separating the chest cavity from the abdominal......
high-risk pregnancy
high-risk pregnancy, pregnancy in which the mother, the fetus, or the newborn has an elevated risk of experiencing......
hikikomori
hikikomori, condition in which a person is socially avoidant to the point of staying isolated at home for at least......
hip dysplasia
hip dysplasia, abnormal development of the hip joint, in which the socket of the pelvis, known as the acetabulum,......
hip fracture
hip fracture, in pathology, a break in the proximal (upper) end of the femur. Hip fracture can occur at any age.......
His, Wilhelm
Wilhelm His was a Swiss-born German anatomist and embryologist who created the science of histogenesis, or the......
histogenesis
histogenesis, series of organized, integrated processes by which cells of the primary germ layers of an embryo......
histoplasmosis
histoplasmosis, infection with the fungus Histoplasma capsulatum, occurring in humans and other animals. The disease......
History of Cancer: A Timeline
The history of cancer research and treatment is marked by centuries of scientific inquiry and medical innovation.......
History of the AIDS Crisis: A Timeline
The AIDS crisis emerged in the early 1980s as a mysterious and terrifying disease that affected various communities......
HIV/AIDS: Just the Facts
What we know about one of the worst pandemics in human history. Companion, HIV, AIDS, HIV/AIDS, human immunodeficiency......