Sleep-wake Cycle

picture info	Sleep-wake Cycle A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment ( entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''circa'', meaning "approximately", and ''dies'', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cycles. In clinical settings, an abnormal circadian rhythm in humans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Endogeny (biology) Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological disord ... is an exogenous synthetic estrogen, commonly used in birth control pills. References External links {{Wiktionary-inline, endogeny Biology ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]
	Tamarind Tamarind (''Tamarindus indica'') is a Legume, leguminous tree bearing edible fruit that is probably indigenous to tropical Africa. The genus ''Tamarindus'' is monotypic taxon, monotypic, meaning that it contains only this species. It belongs to the family Fabaceae. The tamarind tree produces brown, pod-like fruits that contain a sweet, tangy pulp, which is used in cuisines around the world. The pulp is also used in traditional medicine and as a metal polish. The tree's wood can be used for woodworking and Tamarind#Tamarind seed oil and kernel powder, tamarind seed oil can be extracted from the seeds. Tamarind's tender young leaves are used in Indian cuisine, Indian and Filipino cuisine. Because tamarind has multiple uses, it is cultivated around the world in Tropical zone, tropical and Subtropics, subtropical zones. Description The tamarind is a long-lived, medium-growth tree, which attains a maximum crown (botany), crown height of . The crown has an irregular, vase-shaped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Drosophila Pseudoobscura ''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit. They should not be confused with the Tephritidae, a related family, which are also called fruit flies (sometimes referred to as "true fruit flies"); tephritids feed primarily on unripe or ripe fruit, with many species being regarded as destructive agricultural pests, especially the Mediterranean fruit fly. One species of ''Drosophila'' in particular, ''D. melanogaster'', has been heavily used in research in genetics and is a common model organism in developmental biology. The terms "fruit fly" and "''Drosophila''" are often used synonymously with ''D. melanogaster'' in modern biological literature. The entire genus, however, contains more than 1,500 species and is very diverse in appearance, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages thereof being egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially juvenile hormone, prothoracicotropic hormone, and ecdysone. The act of becoming a pupa is called pupation, and the act of emerging from the pupal case is called eclosion or emergence. The pupae of different groups of insects have different names such as ''chrysalis'' for the pupae of butterflies and ''tumbler'' for those of the mosquito family. Pupae may further be enclosed in other structures such as cocoons, nests, or shells. Position in life cycle The pupal stage follows the larval stage and precedes adulthood (''imago'') in insects with complete metamorphosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Eclosion A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages thereof being egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially juvenile hormone, prothoracicotropic hormone, and ecdysone. The act of becoming a pupa is called pupation, and the act of emerging from the pupal case is called eclosion or emergence. The pupae of different groups of insects have different names such as ''chrysalis'' for the pupae of butterflies and ''tumbler'' for those of the mosquito family. Pupae may further be enclosed in other structures such as cocoons, nests, or shells. Position in life cycle The pupal stage follows the larval stage and precedes adulthood (''imago'') in insects with complete metamorphosis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Colin Pittendrigh Colin Stephenson Pittendrigh (October 13, 1918 – March 19, 1996) "Colin Pittendrigh, 'Father of biological clock,' dies at 77", March 25, 1996, accessed April 9, 2011. was a British-born biologist who spent most of his adult life in the United States. Pittendrigh is regarded as the "father of the biological clock," and founded the modern field of chronobiology alongside Jürgen Aschoff and Erwin Bünnin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]