Life Cycle, Processes & Properties, CHR-CRO
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
chromatid
chromatid, one of a pair of daughter strands of a replicated chromosome. Chromatids serve an essential role in......
chromatophore
chromatophore, pigment-containing cell in the deeper layers of the skin of animals. Depending on the colour of......
chromoblastomycosis
chromoblastomycosis, chronic fungal infection of the skin and subcutaneous tissues that is characterized by the......
chromosomal disorder
chromosomal disorder, any syndrome characterized by malformations or malfunctions in any of the body’s systems,......
chronic granulomatous disease
chronic granulomatous disease, a group of rare inherited diseases characterized by the inability of certain white......
Chronic kidney disease
Chronic kidney disease, condition characterized by the progressive loss of the ability of the kidneys to filter......
chronic obstructive pulmonary disease
chronic obstructive pulmonary disease (COPD), progressive respiratory disease characterized by the combination......
chronic traumatic encephalopathy
chronic traumatic encephalopathy (CTE), degenerative brain disease typically associated with repetitive trauma......
chronic venous insufficiency
chronic venous insufficiency (CVI), condition in which the veins in the legs no longer efficiently return blood......
chyme
chyme, a thick semifluid mass of partially digested food and digestive secretions that is formed in the stomach......
Chédiak-Higashi syndrome
Chédiak-Higashi syndrome, a rare inherited childhood disease characterized by the inability of white blood cells......
ciliaris muscle
ciliaris muscle, muscle of the ciliary body of the eye, between the sclera (white of the eye) and the fine ligaments......
circadian rhythm
circadian rhythm, the cyclical 24-hour period of human biological activity. Within the circadian (24-hour) cycle,......
circulation
circulation, in anatomy and physiology, the continuous movement of blood throughout the body, driven by the pumping......
cirrhosis
cirrhosis, irreversible change in the normal liver tissue that results in the degeneration of functioning liver......
Clapp, Cornelia Maria
Cornelia Maria Clapp was an American zoologist and educator whose influence as a teacher was great and enduring......
claustrophobia
claustrophobia, persistent extreme irrational fear of enclosed or confined spaces. The word claustrophobia is derived......
Cleaning behaviour
Cleaning behaviour, self-grooming, as the action of a bird in preening its feathers, or mutual grooming as part......
cleavage
cleavage, in embryology, the first few cellular divisions of a zygote (fertilized egg). Initially, the zygote splits......
cleft lip
cleft lip, relatively common congenital deformity in which the central to medial upper lip fails to fuse properly......
cleft palate
cleft palate, congenital deformity in which the palatal shelves (in the roof of the mouth) fail to close during......
cleidocranial dysostosis
cleidocranial dysostosis, rare congenital, hereditary disorder characterized by collarbones that are absent or......
Clever Hans
Clever Hans, a performing horse in Berlin in the late 19th and early 20th centuries celebrated for demonstrating......
Cloaca
Cloaca, (Latin: “sewer”), in vertebrates, common chamber and outlet into which the intestinal, urinary, and genital......
clonorchiasis
clonorchiasis, chronic infection caused by the Chinese liver fluke (Clonorchis sinensis), a parasitic worm some......
clostridial infection
clostridial infection, any of several infectious conditions in humans and other animals resulting from Clostridium......
clubfoot
clubfoot, congenital twisting of the foot. In the most common type, called talipes equinovarus, the heel bends......
Clubroot
Clubroot, disease of plants of the mustard family (Brassicaceae) caused by the funguslike soil pathogen Plasmodiophora......
cluster headache
cluster headache, Vascular headache that recurs in clusters. Cluster headaches, which occur predominantly in men,......
cocaine
cocaine, white crystalline alkaloid that is obtained from the leaves of the coca plant (Erythroxylum coca), a bush......
coccidioidomycosis
coccidioidomycosis, an infectious disease caused by inhalation of spores of the fungus Coccidioides immitis or......
coccidiosis
coccidiosis, any of several gastrointestinal infections of humans and other animals produced by sporozoan parasites......
Cocoon
Cocoon, a case produced in the larval stage of certain animals (e.g., butterflies, moths, leeches, earthworms,......
Coffee rust
Coffee rust, devastating foliar disease of coffee plants caused by the fungus Hemileia vastatrix. Coffee rust has......
Cold-bloodedness
Cold-bloodedness, the state of having a variable body temperature that is usually only slightly higher than the......
colic
colic, in horses, any of a number of disease conditions that are associated with clinical signs of abdominal pain.......
colic
colic, pain produced by the contraction of the muscular walls of any hollow organ, such as the renal pelvis, the......
coloboma
coloboma, failure of one or more structures in the eye to fuse during embryonic life, creating a congenital fissure......
colony
colony, in zoology, a group of organisms of one species that live and interact closely with each other. A colony......
colony collapse disorder
colony collapse disorder (CCD), disorder affecting honeybee colonies that is characterized by sudden colony death,......
Colorado tick fever
Colorado tick fever, acute febrile viral infection usually transmitted to humans by the bite of the Rocky Mountain......
coloration
coloration, in biology, the general appearance of an organism as determined by the quality and quantity of light......
- Introduction
- Interference, Pigments, Structural
- Carotenoids, Melanins, Flavonoids
- Nitrogenous Pigments
- Indole, Pigments, Biology
- Pigments, Melanin, Camouflage
- Camouflage, Mimicry, Signaling
- Countershading, Camouflage, Adaptation
- Camouflage, Mimicry, Warning
- Illumination, Camouflage, Adaptation
- Camouflage, Mimicry, Signaling
- Adaptation, Camouflage, Mimicry
colorectal cancer
colorectal cancer, disease characterized by uncontrolled growth of cells within the large intestine (colon) or......
colour blindness
colour blindness, inability to distinguish one or more of the three colours red, green, and blue. Most people with......
colour vision
colour vision, ability to distinguish among various wavelengths of light waves and to perceive the differences......
coma
coma, state of unconsciousness, characterized by loss of reaction to external stimuli and absence of spontaneous......
combat fatigue
combat fatigue, a neurotic disorder caused by the stress involved in war. This anxiety-related disorder is characterized......
common cold
common cold, acute viral infection that starts in the upper respiratory tract, sometimes spreads to the lower respiratory......
common garden insects and their larvae
Many people are familiar with the friendly ladybug or handled a woolly bear caterpillar as a child, but fewer,......
comorbidity
comorbidity, in medicine, a disease or condition that coexists with but often is independent of another disease......
complement
complement, in immunology, a complex system comprising a large number of proteins that act in concert to help eliminate......
concealing coloration
concealing coloration, in animals, the use of biological coloration to mask location, identity, and movement, providing......
concussion
concussion, a temporary loss of brain function typically resulting from a relatively mild injury to the brain,......
conduct disorder
conduct disorder (CD), behavior disorder characterized by a pattern of aggression toward others, a lack of concern......
cone
cone, light-sensitive cell (photoreceptor) with a conical projection in the retina of the vertebrate eye, associated......
congenital adrenal hyperplasia
congenital adrenal hyperplasia, any of a group of inherited disorders that are characterized by enlargement of......
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......
congenital hip dislocation
congenital hip dislocation, disorder of unknown cause in which the head of the thighbone (femur) is displaced from......
congestive heart failure
congestive heart failure, Heart failure resulting in the accumulation of fluid in the lungs and other body tissues.......
conidium
conidium, a type of asexual reproductive spore of fungi (kingdom Fungi) usually produced at the tip or side of......
conjoined twin
conjoined twin, one of a pair of twins who are physically joined and often share some organs. Fusion is typically......
Conjugation
Conjugation, in biology, sexual process in which two lower organisms of the same species, such as bacteria, protozoans,......
conjunctivitis
conjunctivitis, inflammation of the conjunctiva, the delicate mucous membrane that lines the inner surface of the......
connective tissue disease
connective tissue disease, any of the diseases that affect human connective tissue. Diseases of the connective......
constipation
constipation, delayed passage of waste through the lower portion of the large intestine, with the possible discharge......
contact dermatitis
contact dermatitis, localized redness and swelling of the skin, together with the formation of vesicles (blisters)......
conversion disorder
conversion disorder, a type of mental disorder in which a wide variety of sensory, motor, or psychic disturbances......
convulsion
convulsion, condition characterized by violent, uncontrolled spasmodic contractions and relaxations of the voluntary......
Cooperative foraging
Cooperative foraging, in biology, the process by which individuals in groups benefit by working together to gain......
Coprophagy
Coprophagy, eating of dung, or feces, considered abnormal among human beings but apparently instinctive among certain......
cor pulmonale
cor pulmonale, enlargement of the right ventricle of the heart, resulting from disorders of the lungs or blood......
corm
corm, vertical, fleshy, underground stem that acts as a food-storage structure in certain seed plants. It bears......
corn
corn, in skin disease, horny thickening of the skin on the foot or toes, produced by repeated friction or pressure.......
Corn earworm
Corn earworm, larva of the moth Heliothis zea (in some classifications H. armigera; family Noctuidae). The smooth,......
Corn smut
Corn smut, plant disease caused by the fungus Ustilago maydis, which attacks corn (maize) and teosinte plants.......
cornea
cornea, dome-shaped transparent membrane about 12 mm (0.5 inch) in diameter that covers the front part of the eye.......
Corner, George Washington
George Washington Corner was an American anatomist and embryologist, best known for his contributions to reproductive......
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......
Cottonseed
Cottonseed, seed of the cotton plant, important commercially for its oil and other products. Cottonseed oil is......
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......
COVID-19 in 20 Questions
These questions and answers have been provided to Britannica by the HudsonAlpha Institute for Biotechnology, a......
COVID-19 Terminology Explained
COVID-19 has become a household term. But what does COVID-19 mean? And why does the virus that causes COVID-19......
Cow
Cow, in common parlance, a domestic bovine, regardless of sex and age, usually of the species Bos taurus. In precise......
cowpox
cowpox, uncommon mildly eruptive disease of animals, first observed in cows and occurring particularly in cats,......
cramp
cramp, painful, involuntary, and sustained contraction of muscle, most common in the limbs but also affecting certain......
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......
crawling
crawling, a pattern of prone locomotion in which the abdomen is in contact with the surface of support. The onset......
Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease (CJD), rare fatal degenerative disease of the central nervous system. CJD occurs throughout......
cri-du-chat syndrome
cri-du-chat syndrome, congenital disorder caused by partial deletion of the short arm of chromosome 5. It is named......
Crohn disease
Crohn disease, chronic inflammation of the digestive tract, usually occurring in the terminal portion of the ileum,......
cross-fertilization
cross-fertilization, the fusion of male and female gametes (sex cells) from different individuals of the same species.......
cross-pollination
cross-pollination, type of pollination in which sperm-laden pollen grains are transferred from the cones or flowers......
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......