Dictionary > Symmetry

Symmetry

Definition
noun, plural: symmetries
Correspondence of parts (in terms of form, size, distribution, or arrangement) on opposite sides of a dividing plane or on sides around an axis
Supplement
In biology, symmetry pertains to an attribute of organisms showing regularity in parts on a plane or around an axis. An organism that is symmetrical (showing symmetry) would have a balanced distribution of duplicate parts on each side of the axis. In most instances, the parts are not an exact but a near repetition. This also accounts for the patterns in nature. The absence of symmetry is termed asymmetry.
Examples of symmetry in organisms are bilateral symmetry, radial symmetry, and biradial symmetry. Bilateral symmetry is a form of symmetry in which the opposite sides are similar. The external appearance is the same on the left and right sides in a sagittal plane (such as the body plan of most animals, including humans).
Radial symmetry is a symmetry in which the sides exhibit correspondence or regularity of parts around a central axis. It is lacking left and right sides (e.g. sea stars, sea anemones, jellyfish, sea urchins, and many flowers). Biradial symmetry is a combination of radial and bilateral symmetries. An example is that of ctenophores (comb jellies).
Related term(s):


You will also like...

Carbohydrates, fats and proteins - dietary sources
A Balanced Diet – Carbohydrates and Fat

Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. If you want an ove..

Ploidy
Polyploidy

Humans are diploid creatures. This means that for every chromosome in the body, there is another one to match it. Howeve..

Lotic community of algal species
Lotic Communities & Algae

Lotic communities have conditions that are rather harsh for typical plants. Thus, the diversity of plant species in loti..

Structural depiction of catalase, an enzyme
Protein Activity and Cellular Metabolism

Proteins have a crucial role in various biological activities. Get to know how proteins are able to perform as enzymes, ..

Population Regulation in an Ecosystem
Population Regulation in an Ecosystem

With regard to the population size of a species and what factors may affect them, two factors have been defined. They ar..

dinosaurs
The Dinosaurs

Dinosaurs represented a major turn in the evolutionary development of organisms on Earth. The first dinosaurs were presu..