Those animals in which the protoplasmic mass, constituting the egg, is converted into a multitude of cells, which are metamorphosed into the tissues of the body. A central cavity is commonly developed, and the cells around it are at first arranged in two layers, -- the ectoderm and endoderm. The group comprises nearly all animals except the Protozoa.
Multicelluar animals whose cells become differentiated to form tissues.
multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity and nervous system
A group that encompasses all animals having a body comprised of cells differentiated into tissues, and having organs, usually including a digestive cavity lined with specialized cells. See also: Protozoa.
Multicellular animals with a nervous system and tissues.
Gr. meta - after, beyond; Gr. zoon - animal]. The Subkingdom of the Kingdom Animalia that includes all mulitcellular animals developing from embryos and possessing differentiated cells which form into tissues.
Metazoa usually refers to the animals with numerous cells which are arranged in layers or groups resulting in the formation of organs, fully differentiated tissues, including nerves and muscles. Different cells here can follow different lines of specialization to perform various functions. Characteristic of metazoa is the process of embryonic development by which the fertilized egg passes through a series of changes culminating in the formation of the adult.
