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The monocots or monocotyledons have, as the name implies, a single (mono-) cotyledon, or embryonic leaf, in their seeds.Historically, this feature was used to contrast the monocots with the dicotyledons or dicots which typically have two cotyledons; however, modern research has shown that the dicots are not a natural group, and the term can only be used to indicate all angiosperms that are not ...
In biology, evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organization , from kingdoms to species , and individual organisms and molecules , such as DNA and proteins .
The length of this process should depend upon a combination of depth and sedimentation rate. Moss [ 7 ] gives the example of Lake Tanganyika , which reaches a depth of 1500 m and has a sedimentation rate of 0.5 mm/yr. Assuming that sedimentation is not influenced by anthropogenic factors, this system should go extinct in approximately 3 million ...
Location theory has become an integral part of economic geography, regional science, and spatial economics. Location theory addresses questions of what economic activities are located where and why. Location theory addresses questions of what economic activities are located where and why.
The tree of life or universal tree of life is a metaphor, conceptual model, and research tool used to explore the evolution of life and describe the relationships between organisms, both living and extinct, as described in a famous passage in Charles Darwin's On the Origin of Species (1859). [1]
Process model: An organized arrangement of systems concepts and principles that portray the behavior of a system through time. Its metaphor is the "motion-picture" of "movie" of the system. Structure–organization–process: See Structure–organization–process for various definitions.
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus.The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines.