Animal - History of classification

Animals are a major group of organisms, classified as the kingdom Animalia or Metazoa. In general they are multicellular, capable of locomotion and responsive to their environment, and feed by consuming other organisms. Their body plan becomes fixed as they develop, usually early on in their development as embryos, although some undergo a process of metamorphosis later on. The name animal comes from the Latin word animal, of which animalia is the plural, and ultimately from anima, meaning vita ...

Including:

• Animal - Characteristics
• Animal - Structure
• Animal - Reproduction and development
• Animal - Origin and fossil record
• Animal - Groups of animals
• Animal - Deuterostomes
• Animal - Ecdysozoa
• Animal - Platyzoa
• Animal - Lophotrochozoa
• Animal - History of classification
• Animal - Usage of the word animal
• Animal - Examples
• Animal - Reference

Read more here: » Animal: Encyclopedia - Animal

Aristotle divided the living world between animals and plants, and this was followed by Carolus Linnaeus in the first hierarchical classification. Since then biologists have begun emphasizing evolutionary relationships, and so these groups have been restricted somewhat. For instance, microscopic protozoa were originally considered animals because they move, but are now treated separately. In Linnaeus' original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mamma ...

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Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - History of classification

The sponges (Porifera) diverged from other animals early. As mentioned, they lack the complex organization found in most other phyla. Their cells are differentiated, but not organized into distinct tissues. Sponges are sessile and typically feed by drawing in water through pores all over the body, which is supported by a skeleton typically divided into spicules. The extinct Archaeocyatha, which have fused skeletons, ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Groups of animals

Some well-known types of animals, listed by their common names: alligator alpaca ant antelope badger bat bear bee beetle bird bison butterfly cat chicken chimpanzee cockroach coral cow crocodile deer dinosaur dog dolphin earthworm elephant elk fish fly fox frog< ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Examples

Animals are generally considered to have evolved from flagellate protozoa. Their closest living relatives are the choanoflagellates, collared flagellates that have the same structure as certain sponge cells do. Molecular studies place them in a supergroup called the opisthokonts, which also include the fungi and a few small parasitic protists. The name comes from the posterior location of the flagellum in motile cells, such as most animal sperm, where ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Origin and fossil record

Aristotle divided the living world between animals and plants, and this was followed by Carolus Linnaeus in the first hierarchical classification. Since then biologists have begun emphasizing evolutionary relationships, and so these groups have been restricted somewhat. For instance, microscopic protozoa were originally considered animals because they move, but are now treated separately. Kingdom Animalia has several characteristics that set it apart from other living things. Animals are eukaryotic and multicellular, which separates t ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Characteristics

With a few exceptions, most notably the sponges (Phylum Porifera), animals have bodies differentiated into separate tissues. These include muscles, which are able to contract and control locomotion, and a nervous system, which sends and processes signals. There is also typically an internal digestive chamber, with one or two openings. Animals with this sort of organization are called metazoans, or eumetazoans when the fo ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Structure

Nearly all animals undergo some form of sexual reproduction. Adults are diploid or occasionally polyploid. They have a few specialized reproductive cells, which undergo meiosis to produce smaller motile spermatozoa or larger non-motile ova. These fuse to form zygotes, which develop into new individuals. Many animals are also capable of asexual reproduction. This may take place through parthenogenesis, where fertile eggs are produced ...

See also:

Animal, Animal - Characteristics, Animal - Structure, Animal - Reproduction and development, Animal - Origin and fossil record, Animal - Groups of animals, Animal - Deuterostomes, Animal - Ecdysozoa, Animal - Platyzoa, Animal - Lophotrochozoa, Animal - History of classification, Animal - Usage of the word animal, Animal - Examples, Animal - Reference

Read more here: » Animal: Encyclopedia II - Animal - Reproduction and development