Biology, CON-DO
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
congenital disorder
congenital disorder, abnormality of structure and, consequently, function of the human body arising during development.......
congenital heart disease
congenital heart disease, any abnormality of the heart that is present at birth. Cardiac abnormalities are generally......
conidium
conidium, a type of asexual reproductive spore of fungi (kingdom Fungi) usually produced at the tip or side of......
conjunctivitis
conjunctivitis, inflammation of the conjunctiva, the delicate mucous membrane that lines the inner surface of the......
connective tissue
connective tissue, group of tissues in the body that maintain the form of the body and its organs and provide cohesion......
connective tissue disease
connective tissue disease, any of the diseases that affect human connective tissue. Diseases of the connective......
contractile vacuole
contractile vacuole, regulatory organelle, usually spherical, found in freshwater protozoa and lower metazoans,......
cornea
cornea, dome-shaped transparent membrane about 12 mm (0.5 inch) in diameter that covers the front part of the eye.......
coronary circulation
coronary circulation, part of the systemic circulatory system that supplies blood to and provides drainage from......
coronary heart disease
coronary heart disease, disease characterized by an inadequate supply of oxygen-rich blood to the heart muscle......
coronavirus
coronavirus, a group of viruses known for their ability to cause respiratory and gastrointestinal infections in......
cotyledon
cotyledon, seed leaf within the embryo of a seed. Cotyledons help supply the nutrition a plant embryo needs to......
cough
cough, an expulsive reflex initiated when the respiratory tract is irritated by infection, noxious fumes, dust,......
Courtship
Courtship, in animals, behaviour that results in mating and eventual reproduction. Courtship may be rather simple,......
COVID-19
COVID-19, highly contagious respiratory illness, the cause of the COVID-19 pandemic. COVID-19 was first detected......
cowpox
cowpox, uncommon mildly eruptive disease of animals, first observed in cows and occurring particularly in cats,......
Coxal gland
Coxal gland, in certain arthropods, one of a pair of excretory organs consisting of an end sac where initial urine......
craniopharyngioma
craniopharyngioma, benign brain tumour arising from the pituitary gland. Although most common in children, it can......
craniosynostosis
craniosynostosis, any of several types of cranial deformity—sometimes accompanied by other abnormalities—that result......
Creative evolution
Creative evolution, a philosophical theory espoused early in the 20th century by Henri Bergson, a French process......
Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease (CJD), rare fatal degenerative disease of the central nervous system. CJD occurs throughout......
cross-modal plasticity
cross-modal plasticity, the ability of the brain to reorganize and make functional changes to compensate for a......
croup
croup, acute respiratory illness of young children characterized by a harsh cough, hoarseness, and difficulty breathing.......
Crown gall
Crown gall, plant disease, caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter). Thousands......
Cryoflora
Cryoflora, algae that live in snow and ice. The well-known and widely distributed red snow (q.v.) is caused by......
cryoglobulinemia
cryoglobulinemia, presence in the blood of proteins called cryoglobulins that precipitate at temperatures below......
Cryptomonad
Cryptomonad, (class Cryptophyceae), any of several genera of small biflagellate algae occurring in both fresh and......
cryptorchidism
cryptorchidism, disorder in which one or both of the testes do not descend spontaneously to the usual position......
cultivar
cultivar, Any variety of a plant, originating through cloning or hybridization (see clone, hybrid), known only......
cumulative incidence
cumulative incidence, in epidemiology, estimate of the risk that an individual will experience an event or develop......
Cup fungus
Cup fungus, any member of a large group of fungi (kingdom Fungi) in the order Pezizales (phylum Ascomycota) and......
Curious uses of urine through the ages
“Gross!” is how most of us are likely to describe urine—that foul-smelling liquid byproduct of excretion. Unless......
Curly top
Curly top, viral disease affecting numerous cultivated and wild plants worldwide. Diseased plants are usually stunted......
Cuticle
Cuticle, the outer layer or part of an organism that comes in contact with the environment. In many invertebrates......
cutis laxa
cutis laxa, rare disorder in which the skin hangs in loose folds. The cause of cutis laxa is unknown, but the defect......
cyclic vomiting syndrome
cyclic vomiting syndrome, condition characterized by sudden repeated episodes of severe nausea and vomiting, the......
cyst
cyst, in biology, enclosed sac within body tissues, having a distinct membrane and generally containing a liquid......
cystinosis
cystinosis, inborn error of metabolism resulting in the deposition of crystals of the amino acid cystine in various......
cystinuria
cystinuria, hereditary error of metabolism characterized by the excessive excretion into the urine of four amino......
cystitis
cystitis, acute or chronic inflammation of the urinary bladder. The bladder, the storage sac for urine, is lined......
cytogenetics
cytogenetics, in cell biology, field that deals with chromosomes and their inheritance, particularly as applied......
cytokinesis
cytokinesis, in biology, the process by which one cell physically divides into two cells. Cytokinesis represents......
cytomegalovirus
cytomegalovirus (CMV), any of several viruses in the herpes family (Herpesviridae), frequently involved in human......
cytoplasm
cytoplasm, the semifluid substance of a cell that is external to the nuclear membrane and internal to the cellular......
cytoplasmic streaming
cytoplasmic streaming, the movement of the fluid substance (cytoplasm) within a plant or animal cell. The motion......
cytoskeleton
cytoskeleton, a system of filaments or fibres that is present in the cytoplasm of eukaryotic cells (cells containing......
dacryocystitis
dacryocystitis, inflammation and infection of the lacrimal sac, usually stemming from obstruction of the flow of......
Damping-off
Damping-off, destructive disease of plant seedlings. Damping-off is caused by a number of seed- and soil-borne......
Darwinism
Darwinism, theory of the evolutionary mechanism propounded by Charles Darwin as an explanation of organic change.......
de Toni–Fanconi syndrome
de Toni–Fanconi syndrome, a metabolic disorder affecting kidney transport, characterized by the failure of the......
deafness
deafness, partial or total inability to hear. The two principal types of deafness are conduction deafness and nerve......
death
death, the total cessation of life processes that eventually occurs in all living organisms. The state of human......
- Introduction
- Mortality, Grief, Loss
- Process, Event, Causes
- Cell Death, Apoptosis, Necrosis
- Brainstem, Cells, Death
- Brainstem, Diagnosis, Tests
- Ancient Egypt, Rituals, Beliefs
- Mesopotamia, Mortality, Beliefs
- Hinduism, Reincarnation, Karma
- Afterlife, Immortality, Soul
- Resurrection, Judgment, Afterlife
- Descartes, Pineal, Brainstem
- Attitudes, Beliefs, Rituals
death cap
death cap, (Amanita phalloides), species of poisonous mushroom, the deadliest known to humans. The death cap is......
defecation
defecation, the act of eliminating solid or semisolid waste materials (feces) from the digestive tract. In human......
dehydration
dehydration, loss of water from the body; it is almost invariably associated with some loss of salt (sodium chloride)......
delayed puberty
delayed puberty, failure of the physical development of the reproductive system by the normal stage or period of......
delirium
delirium, a mental disturbance marked by disorientation and confused thinking in which the patient incorrectly......
deltoideus muscle
deltoideus muscle, large, triangular muscle that covers the shoulder and serves mainly to raise the arm laterally.......
delusion
delusion, in psychology, a rigid system of beliefs with which a person is preoccupied and to which the person firmly......
deme
deme, in biology, a population of organisms within which the exchange of genes is completely random; i.e., all......
dementia
dementia, general term for any of a number of conditions marked by chronic, usually progressive deterioration of......
dendrology
dendrology, study of the characteristics of trees, shrubs, lianas, and other woody plants. Dendrology is generally......
Denitrifying bacteria
Denitrifying bacteria, microorganisms whose action results in the conversion of nitrates in soil to free atmospheric......
Deoxyribose
Deoxyribose, five-carbon sugar component of DNA (q.v.; deoxyribonucleic acid), where it alternates with phosphate......
dermatitis
dermatitis, an inflammation of the skin usually characterized by redness, swelling, blister formation, and oozing......
dermatochalasis
dermatochalasis, sagging of the eyelid skin and underlying muscle that occurs commonly during the aging process.......
dermatomyositis
dermatomyositis, chronic progressive inflammation of the skin and muscles, particularly the muscles of the shoulders......
dermis
dermis, the thicker, deeper layer of the skin underlying the epidermis and made up of connective tissue. It is......
Desmid
Desmid, (order Desmidiales), order of single-celled (sometimes filamentous or colonial) microscopic green algae,......
desquamation
desquamation, peeling or shedding of the superficial portion of the epidermis, or outermost layer of the skin.......
detached retina
detached retina, eye disorder involving separation of the transparent light-sensing portion of the retina from......
deuteromycetes
deuteromycetes, fungi (kingdom Fungi) in which a true sexual state is uncommon or unknown. Many of these fungi......
Deviously Darwinian: 6 Strange Evolutionary Phenomena
Like the laws of human society, the laws of natural selection are ripe for exploitation. It isn’t just survival......
Devonian extinctions
Devonian extinctions, a series of mass extinction events primarily affecting the marine communities of the Devonian......
diabetes insipidus
diabetes insipidus, pathological endocrine condition characterized by excessive thirst and excessive production......
diabetes mellitus
diabetes mellitus, disorder of carbohydrate metabolism characterized by impaired ability of the body to produce......
diabetic nephropathy
diabetic nephropathy, deterioration of kidney function occurring as a complication of diabetes mellitus. The condition......
Diapause
Diapause, spontaneous interruption of the development of certain animals, marked by reduction of metabolic activity.......
diaphragm
diaphragm, dome-shaped, muscular and membranous structure that separates the thoracic (chest) and abdominal cavities......
diarrhea
diarrhea, abnormally swift passage of waste material through the large intestine, with consequent discharge of......
diastole
diastole, in the cardiac cycle, period of relaxation of the heart muscle, accompanied by the filling of the chambers......
Diatom
Diatom, (class Bacillariophyceae), any member of the algal class Bacillariophyceae (division Chromophyta), with......
Dieback
Dieback, common symptom or name of disease, especially of woody plants, characterized by progressive death of twigs,......
Diego blood group system
Diego blood group system, classification of human blood according to the properties conferred by the presence of......
digestion
digestion, sequence by which food is broken down and chemically converted so that it can be absorbed by the cells......
digestive system disease
digestive system disease, any of the diseases that affect the human digestive tract. Such disorders may affect......
- Introduction
- Dental Caries, Oral Health, Bacteria
- Esophageal Disorders, Gastrointestinal Issues, Dysphagia
- Motility, Symptoms, Treatment
- Diverticula, Symptoms, Treatment
- Gastric Ulcers, Gastritis, Dyspepsia
- Gastritis, Symptoms, Causes
- Travelers' Diarrhea
- Parasitic Infections
- Colitis, Crohn's, Ulcerative
- Abscesses, Symptoms, Treatment
- Crohn's, Inflammatory Bowel, Autoimmune
- Liver Disease, Symptoms, Treatment
- Acute Cholestatic Hepatitis, Canalicular Injury, Liver Damage
- Liver Complications, Advanced Disease, Symptoms
- Biliary Tract, Symptoms, Treatment
- Jaundice, Liver, Pancreas
- Pancreatitis, Chronic, Symptoms
digestive system, human
human digestive system, system used in the human body for the process of digestion. The human digestive system......
- Introduction
- Teeth, Enzymes, Digestion
- Salivary Glands, Enzymes, Digestion
- Pharynx, Esophagus, Stomach
- Esophagus, Stomach, Intestines
- Blood, Nerve Supply
- Gastric Mucosa, Digestive Processes, Enzymes
- Gastric Secretion, Digestive Process, Nutrient Absorption
- Anatomy, Organs, Processes
- Contractions, Motility, Digestion
- Enzymes, Absorption, Nutrients
- Secretions, Enzymes, Absorption
- Rectum, Anus, Digestion
- Organs, Processes, Functions
- Microscopic Anatomy, Organs, Processes
- Bile, Enzymes, Absorption
- Islet Cells, Digestion, Nutrition
- Proteins, Enzymes, Absorption
- Fats, Enzymes, Absorption
- Calcium, Enzymes, Absorption
- Intestinal Gas, Digestive Process, Nutrition
- Hormones, Enzymes, Absorption
- Gastrointestinal Tract, Immunity, Digestion
- Evolution, Development, Anatomy
digestive system, Invertebrate
Invertebrate digestive system, any of the systems used by invertebrates for the process of digestion. Included......
digit malformation
digit malformation, in human physiology, any of the isolated anomalies of the digits (fingers or toes) in an otherwise......
dilator muscle
dilator muscle, any of the muscles that widen a body part. In humans, the dilator muscle of the iris contains fibres......
Dinoflagellate
Dinoflagellate, (division Dinoflagellata), any of numerous one-celled aquatic organisms bearing two dissimilar......
diphtheria
diphtheria, acute infectious disease caused by the bacillus Corynebacterium diphtheriae and characterized by a......
diplomonad
diplomonad, any member of the protozoan order Diplomonadida. Diplomonads are small zooflagellates that inhabit......
disease
disease, any harmful deviation from the healthy structural or functional state of an organism, generally associated......
dissociative disorder
dissociative disorder, any of several mental disturbances in humans in which normally integrated mental functions,......
diverticulum
diverticulum, any small pouch or sac that forms in the wall of a major organ of the human body. Diverticula form......
DNA
DNA, organic chemical of complex molecular structure that is found in all prokaryotic and eukaryotic cells and......
DNA fingerprinting
DNA fingerprinting, in genetics, method of isolating and identifying variable elements within the base-pair sequence......
DNA repair
DNA repair, any of several mechanisms by which a cell maintains the integrity of its genetic code. DNA repair ensures......
Do animals dream?
The answer is “probably.” Research has shown that many animals experience a sleep phase similar to humans known......