Veganism () is the practice of abstaining from the use of animal products, particularly in diet, as well as an associated philosophy that rejects the commodity status of sentient animals. A follower of veganism is known as a vegan. Distinctions are sometimes made between different categories of veganism. Dietary vegans (or strict vegetarians) refrain from consuming animal products, not only meat and fish but, in contrast to ovo-lacto vegetarians, also eggs, dairy products and other animal-derived substances, such as honey. The term ethical vegan is often applied to those who not only fol...

The Vegan Society is a registered charity and the oldest vegan society in the world, founded on November 1, 1944, in England by Donald Watson, Elsie "Sally" Shrigley, and 23 others. Watson coined the word "vegan" to stand for "non-dairy vegetarians" who also ate no eggs. The date of the society's founding is celebrated annually as World Vegan Day. The society now defines veganism as "...a way of living that seeks to exclude, as far as possible and practicable, all forms of exploitation of, and cruelty to, animals for food, clothing and any other purpose." Activities * Information –...

:"Bilateral symmetry" redirects here. For bilateral symmetry in mathematics, see reflection symmetry. Symmetry in biology is the balanced distribution of duplicate body parts or shapes. In nature and biology, symmetry is approximate. For example, plant leaves, while considered symmetric, rarely match up exactly when folded in half. Symmetry creates a class of patterns in nature, where the near-repetition of the pattern element is by reflection or rotation. The body plans of most multicellular organisms exhibit some form of symmetry, whether radial symmetry, bilateral symmetry or "spheri...

In colorimetry, metamerism is the matching of apparent color of objects with different spectral power distributions. Colors that match this way are called metamers. A spectral power distribution describes the proportion of total light emitted, transmitted, or reflected by a color sample at every visible wavelength; it precisely defines the light from any physical stimulus. However, the human eye contains only three color receptors (3 types of cone cells), which means that all colors are reduced to three sensory quantities, called the tristimulus values. Metamerism occurs because each type...

In biology, metamerism is a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions. In animals, metameric segments are referred to as somites or metameres. In plants, they are referred to as metamers or, more concretely, phytomers. In animals In animals, metamery is defined as a mesodermal event resulting in serial repetition of unit subdivisions of ectoderm and mesoderm products. Endoderm is not involved in metamery. Segmentation is not the same concept as...