- published: 17 Mar 2013
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A body plan is the blueprint for the way the body of an organism is laid out. Each species of multicellular organism—plant, fungus, red algea, slime mold, among others—has a body plan. This article is about animal body plans.
An animal's symmetry, its number of body segments and number of limbs are all aspects of its body plan. One of the key issues of developmental biology is the evolution of body plans as different as those of a starfish, or a mammal, which come from a close common biological heritage, both are deuterostomes. One issue in particular is how radical changes in body plans have occurred over geological time. The body plan is a key feature of an organism's morphology and, since the discovery of DNA, developmental biologists have been able to learn a lot about how genes control the development of structural features through a cascade of processes in which key genes produce morphogens, chemicals that diffuse through the body to produce a gradient that acts as a position indicator for cells, turning on other genes, some of which in turn produce other morphogens. A key discovery was the existence of groups of homeobox genes in which are responsible for laying down the basic body plan in animals. The homeobox genes are remarkably conserved between species as diverse as the fruitfly and man, the basic segmented pattern of the worm or fruitfly being the origin of the segmented spine in man. The field of animal evolutionary developmental biology, which studies the genetics of morphology in detail is now a rapidly expanding one [1], with many of the developmental genetic cascades, particularly in the fruitfly drosophila, now catalogued in considerable detail.
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death. The study of the workings of the body is physiology.
The human body mostly consists of a head, neck, torso, two arms and two legs, as well as numerous internal organ groups such as respiratory, circulatory and a central nervous system.
The dead body of a human is referred to as a cadaver, or corpse. The dead bodies of vertebrate animals, insects and humans are sometimes called carcasses. The study of the structure of the body is called anatomy. A carcase is the body of a slaughtered animal, after the removal of offal, that is to be used as meat.
In the views emerging from the mind-body dichotomy, the body is considered in behavior and therefore considered as little valued and trivial in comparison to mind, spirit or soul. Materialist philosophers of mind maintain that the mind is not something separate from the body, but is produced by physiological functions of the brain.
A plan is typically any diagram or list of steps with timing and resources, used to achieve an objective. See also strategy. It is commonly understood as a temporal set of intended actions through which one expects to achieve a goal. For spatial or planar topologic or topographic sets see map.
Plans can be formal or informal:
The most popular ways to describe plans are by their breadth, time frame, and specificity; however, these planning classifications are not independent of one another. For instance, there is a close relationship between the short- and long-term categories and the strategic and operational categories.
It is common for less formal plans to be created as abstract ideas, and remain in that form as they are maintained and put to use. More formal plans as used for business and military purposes, while initially created with and as an abstract thought, are likely to be written down, drawn up or otherwise stored in a form that is accessible to multiple people across time and space. This allows more reliable collaboration in the execution of the plan.