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Photoperiodism
Photoperiod is the change of day length around the seasons. The rotation of the earth around its axis produces 24 hour changes in light (day) and dark (night) cycles on earth. The length of the light and dark in each phase varies across the seasons due to the tilt of the earth around its axis. The photoperiod defines the length of the light, for example a summer day the length of light could be 16 hours while the dark is 8 hours, whereas a winter day the length of day could be 8 hours, whereas the dark is 16 hours. Importantly, the seasons are different in the northern hemisphere than the southern hemisphere. Photoperiodism is the physiological reaction of organisms to the length of light or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods. They are classified under three groups according to the photoperiods: short-day plants, long-day plants, and day ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm
A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the environment (is Entrainment (chronobiology), entrained by the environment). Circadian rhythms are regulated by a circadian clock whose primary function is to rhythmically co-ordinate biological processes so they occur at the correct time to maximize the fitness of an individual. Circadian rhythms have been widely observed in animals, plants, fungi and cyanobacteria and there is evidence that they evolved independently in each of these kingdoms of life. The term ''circadian'' comes from the Latin ', meaning "around", and ', 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 ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organ (biology), organs, cell (biology), cells, and biomolecules carry out chemistry, chemical and physics, physical functions in a living system. According to the classes of organisms, the field can be divided into clinical physiology, medical physiology, Zoology#Physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysics, biophysical and biochemical processes, homeostasis, homeostatic control mechanisms, and cell signaling, communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathology, pathological state'' refers to abnormality (behavior), abnormal conditions, including human diseases. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoreceptor Protein
Photoreceptor proteins are light-sensitive proteins involved in the sensing and response to light in a variety of organisms. Some examples are rhodopsin in the photoreceptor cells of the vertebrate retina, phytochrome in plants, and bacteriorhodopsin and bacteriophytochromes in some bacteria. They mediate light responses as varied as visual perception, phototropism and phototaxis, as well as responses to light-dark cycles such as circadian rhythm and other photoperiodisms including control of flowering times in plants and mating seasons in animals. Structure Photoreceptor proteins typically consist of a protein attached to a non-protein chromophore (sometimes referred as photopigment, even so photopigment may also refer to the photoreceptor as a whole). The chromophore reacts to light via photoisomerization or photoreduction, thus initiating a change of the receptor protein which triggers a signal transduction cascade. Chromophores found in photoreceptors include retinal ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyoscyamus Niger
Henbane (''Hyoscyamus niger'', also black henbane and stinking nightshade) is a poisonous plant belonging to tribe Hyoscyameae of the nightshade family ''Solanaceae''. Henbane is native to temperate Europe and Siberia, and naturalised in Great Britain and Ireland. Historical use The name ''henbane'' dates from AD 1265; "bane" meant 'thing that causes death'. Other etymologies of ''henbane'' derive from the Indo-European stem ''bhelena'' meaning "crazy plant" and with the Proto-Germanic element ''bil'' meaning "vision", "hallucination", "magical power", and "miraculous ability". Historically, henbane was used in combination with other plants, such as the mandrake, the deadly nightshade, and datura, as an anaesthetic potion, and for its psychoactive properties in "magic brews". These psychoactive properties include visual hallucinations and a sensation of flight.Schultes & Smith 1976, p. 22 It was originally used in continental Europe, Asia, and the Arab world, though it did sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barley
Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikelets and making it much easier to harvest. Its use then spread throughout Eurasia by 2000 BC. Barley prefers relatively low temperatures and well-drained soil to grow. It is relatively tolerant of drought and soil salinity, but is less winter-hardy than wheat or rye. In 2023, barley was fourth among grains in quantity produced, 146 million tonnes, behind maize, rice, and wheat. Globally, 70% of barley production is used as animal feed, while 30% is used as a source of fermentable material for beer, or further distilled into whisky, and as a component of various foods. It is used in soups and stews and in barley bread of various cultures. Barley grains are commonly made into malt using a traditional and ancient method of preparatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lettuce
Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae mostly grown as a leaf vegetable. The leaves are most often used raw in Green salad, green salads, although lettuce is also seen in other kinds of food, such as sandwiches, wraps and soups; it can also be grilled. Its stem and seeds are sometimes used; celtuce (asparagus lettuce) is one variety grown for its stems, which are eaten either raw or cooked. In addition to its main use as a leafy green, it has also gathered religious and medicinal significance over centuries of human consumption. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had spread throughout the world. , world production of lettuce (and chicory) was 27 million tonnes, 53percent of which came from China. Lettuce was originally farmed by the ancient Egyptians, who transformed it from a plant whose seeds were used to obtain oil into an important food crop raised fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheat
Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, wheat species and hybrids include the most widely grown common wheat (''T. aestivum''), spelt, durum, emmer, einkorn, and Khorasan wheat, Khorasan or Kamut. The archaeological record suggests that wheat was first cultivated in the regions of the Fertile Crescent around 9600 BC. Wheat is grown on a larger area of land than any other food crop ( in 2021). World trade in wheat is greater than that of all other crops combined. In 2021, world wheat production was , making it the second most-produced cereal after maize (known as corn in North America and Australia; wheat is often called corn in countries including Britain). Since 1960, world production of wheat and other grain crops has tripled and is expected to grow further through the middle of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation
Rotation or rotational/rotary motion is the circular movement of an object around a central line, known as an ''axis of rotation''. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersecting anywhere inside or outside the figure at a ''center of rotation''. A solid figure has an infinite number of possible axes and angles of rotation, including chaotic rotation (between arbitrary orientation (geometry), orientations), in contrast to rotation around a fixed axis, rotation around a axis. The special case of a rotation with an internal axis passing through the body's own center of mass is known as a spin (or ''autorotation''). In that case, the surface intersection of the internal ''spin axis'' can be called a ''pole''; for example, Earth's rotation defines the geographical poles. A rotation around an axis completely external to the moving body is called a revolution (or ''orbit''), e.g. Earth's orbit around the Sun. The en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Day Plants
Short may refer to: Places * Short (crater), a lunar impact crater on the near side of the Moon * Short, Mississippi, an unincorporated community * Short, Oklahoma, a census-designated place People * Short (surname) * List of people known as the Short Companies * Short Brothers, a British aerospace company * Short Brothers of Sunderland, a former English shipbuilder Computing and technology * Short circuit, an accidental connection between two nodes of an electrical circuit * Short integer, a computer datatype Other uses * Short film, a cinema format, also called a short * Short (finance), stock-trading position * Short (cricket), fielding positions closer to the batsman * SHORT syndrome, a medical condition in which affected individuals have multiple birth defects * Short vowel, a vowel sound of short perceived duration * Holly Short, a fictional character in the ''Artemis Fowl'' series See also * Short time, a situation in which a civilian employee works reduced hours, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winter Solstice
The winter solstice, or hibernal solstice, occurs when either of Earth's geographical pole, poles reaches its maximum axial tilt, tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern Hemisphere, Northern and Southern Hemisphere, Southern). For that hemisphere, the winter solstice is the day with the shortest daytime, period of daylight and longest night of the year, and when the Sun is at its lowest culmination, daily maximum elevation in the sky. Each Polar Circle, polar region experiences polar night, continuous darkness or twilight around its winter solstice. The opposite event is the summer solstice. The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (December 21 or 22) and in the Southern Hemisphere, this is the June solstice (June 20 or 21). Although the winter solstice itself lasts only a moment, the term also refers to the day on which it occurs. Traditionally, in many Tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
