metazoa
後生動物
meta·zoa /ˌmɛtəˈzoə/ 名詞 複數
(單metazoon)後生動物,多細胞動物
Met·a·zo·a n. pl. Zool. 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.
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metazoan
n : any animal of the subkingdom Metazoa; all animals except
protozoans and sponges
[also: metazoa (pl)]
Metazoa
n : multicellular animals having cells differentiated into
tissues and organs and usually a digestive cavity and
nervous system [syn: subkingdom Metazoa]