Bilateral Symmetry


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bilateral symmetry

[bī′lad·ə·rəl ′sim·ə·trē]
(biology)
Symmetry such that the body can be divided by one median, or sagittal, dorsoventral plane into equivalent right and left halves, each a mirror image of the other.

bilateral symmetry

A balanced arrangement of identical similar elements about a central axis.
See also: Symmetry

Bilateral Symmetry

 

two-sided symmetry in organisms; manifested in the fact that the body is divided by a medial plane into right and left halves, each of which is the mirror image of the other. Bilateral symmetry occurs among worms, arthropods, and vertebrates and also plant organs—for example, many stems with leaves or lateral shoots arranged in two rows, stems of many cacti, and so on. Leaves in which the upper and lower surfaces differ in structure are also called bilateral.

References in periodicals archive ?
Disp and CGDI both in mean values and ranges between right and left sides, suggesting bilateral symmetry during opening of jaw.
In the healthy animals grown under appropriate environmental conditions, not stressed and living in a good welfare level, deviation from bilateral symmetry is expected to be small.
Departures from distinctive larval bilateral symmetry such as reductions or complete loss of arms, lobes, or ciliated bands are known in some nonfeeding larval forms of echinoderms.
The biological world is extraordinarily inventive with bilateral symmetry.
These planktonic larvae look nothing like adult sea stars and have bilateral symmetry.
In his discussion of the eight key terms, Freedman notes that four of the nouns are masculine and the other four are feminine, "a clear instance of bilateral symmetry and also supporting the idea of totality and completeness, a theme deeply embedded in this poem through the use of the alphabet and the number 8" (p.
To demonstrate mirror symmetry, also known as line symmetry or bilateral symmetry, we start by creating a whimsical creature.
Subtle deviations from bilateral symmetry continue to attract a great deal of attention as possible measures of individual condition, or quality, in studies of natural and sexual selection (reviews in Moller and Pomiankowski 1993; Watson and Thornhill 1994; Markow 1995; Palmer 1996).
The limited facial asymmetry occurring on either side during normal growth and development is a part of a manifestation of mild fluctuant asymmetry, which is a random deviation from perfect bilateral symmetry in a morphological trait.
At the other extreme we have a historian like Bruno Zevi who sees fascism not only in the axes and formality of Classicism but even in something as elementary as the use of bilateral symmetry - he actually writes of symmetry being 'pathological'.
bilateral symmetry, flag-flowers, trap flowers and the "struggle for space" within the bud; "Floral Adaptation" which looks at different pollinators (mode, style) (Chapter 4) gives us a fascinating array of co-evolutionary syndromes; "Special Differentiations of Pollinator Attractions" (Chapter 5) covers nectaries, elaiophores, perfumes, optical displays, and visual clues; "Special Differentiations Associated with Breeding Systems" (Chapter 6) deals with sex expression, heterostyly, and male/female allocation; and finally "The Process of Anthesis" (Chapter 7) focuses on structural changes during flowering, longevity, rhythmicity, the flowering within individuals and whole populations (Gentry's "Big Bang" species vs.
The act of dividing in two had established the plane of bilateral symmetry.

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