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Visible patterns in nature are governed by physical laws; for example, meanders can be explained using fluid dynamics. In biology , natural selection can cause the development of patterns in living things for several reasons, including camouflage , [ 26 ] sexual selection , [ 26 ] and different kinds of signalling, including mimicry [ 27 ] and ...
With an alternate (spiral) pattern, each leaf arises at a different point (node) on the stem. Distichous leaf arrangement in Clivia Distichous phyllotaxis, also called "two-ranked leaf arrangement" is a special case of either opposite or alternate leaf arrangement where the leaves on a stem are arranged in two vertical columns on opposite sides ...
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symmetry down its centre, or a pine cone displays a clear symmetrical spiral pattern.
Spirals on a sunflower Detail of Aeonium tabuliforme showing the multiple spiral arrangement (parastichy) Parastichy, in phyllotaxy, is the spiral pattern of particular plant organs on some plants, such as areoles on cacti stems, florets in sunflower heads and scales in pine cones. [1] These spirals involve the insertion of a single primordium. [2]
Main whorled patterns. A whorl ( / w ɜːr l / or / w ɔːr l / ) is an individual circle , oval , volution or equivalent in a whorled pattern , which consists of a spiral or multiple concentric objects (including circles , ovals and arcs ).
The Spiralia are a morphologically diverse clade of protostome animals, including within their number the molluscs, annelids, platyhelminths and other taxa. [4] The term Spiralia is applied to those phyla that exhibit canonical spiral cleavage, a pattern of early development found in most members of the Lophotrochozoa.
The "Lophotrochozoa" hypothesis is also supported by the fact that many phyla within this group, including annelids, molluscs, nemerteans and flatworms, follow a similar pattern in the fertilized egg's development. When their cells divide after the 4-cell stage, descendants of these four cells form a spiral pattern.
It describes how patterns in nature, such as stripes and spirals, can arise naturally from a homogeneous, uniform state. The theory, which can be called a reaction–diffusion theory of morphogenesis, has become a basic model in theoretical biology. [2] Such patterns have come to be known as Turing patterns.