Animal, any of a group of multicellular eukaryotic organisms thought to have evolved independently from the unicellular eukaryotes. Animals differ from other multicellular eukaryotes, the plants and the fungi, in morphology and physiology in that animals
The Animal Kingdom comprises of multicellular and eukaryotic species of different kinds. Learn more about its classification into groups in details here.
Animals aremulticellularorganisms.The animal body is composed of several cells performing specific functions as opposed tobacteriaand most protists that are unicellular. The cells may then be organized into various animal tissues, such as epithelial tissues, connective tissues, muscle tissues, nervous ti...
any member of the animal kingdom: organisms that are multicellular and eukaryotic which possess non-photosynthetic, wall-less cells. In some classifications, certain unicellular organisms such as PROTOZOANS are also included. Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunder...
Any eukaryotic multicellular organism of the biological kingdom Animalia is referred to as an animal. The majority of creatures in this kingdom lack a cell wall, are heterotrophic, motile, have specialized sensory organs, and originate from blastula during embryonic development....
Protists are a diverse group of unicellular or multicellular organisms. Protists have membrane-bound organelles and are placed in the Eukarya domain because they are eukaryotes, which means they have a nucleus. Protists are polyphyletic, meaning they are derived from more than one common evolutionar...
A curious form of scanning phototaxis is present in the multicellular slug stage of the slime mouldDictyostelium discoideum.Dictyosteliumbegins life as a spore, germinating into many independent unicellular amoebae. These cells gather and join together to form a multicellular slug, a slime-covered bag...
(5. Animals (Animalia or Zoa)) They are subdivided into a) protozoan (Protista), this group includes amebas, infusoria, and other unicellular organisms; and b) multicellular (Metazoa), comprising sponges, worms, mollusks, arthropods (insects, spiders, crustaceans, etc) and chordates (Chordata) ...
Frequently combined with reproduction by unicellular rudiments, this type of reproduction is often called asexual (in the broad sense of the word) owing to the absence of the sexual process. In origin, however, vegetative and asexual reproduction are different. Among multicellular animals, vegetative...
H. Whittaker, 1969 后生动物界Metazoa 后生植物界Metaphytra 原始有核界Protoctista(单胞藻unicellular algae and 简单的多细胞藻类multicellular algae、粘菌myxomycete、真菌Fungi、原生动物Protozoa) 四界系统:原核生物Prokaryote 真核生物Eukaryote 原核生物界(原核生物Prokaryote)Monera 电子显微镜Electron microscope,...