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一、教材分析动物学(人民教育出版社重印1964年版)除绪论与结语外,按动物从低级类群到高级类群的进化路线分成平行的十二章,前七章是无脊椎动物。原生动物是单细胞动物,腔肠动物则是两胚层,辐射对称的低等多细胞动物,扁形动物、线形动物则进化到三胚层,两侧对称……,直到脊椎动物,胚胎发育仍要重演两胚层阶段(原肠胚)。所以腔肠动物在动物进化史中占有较重要的地位。
First, the textbook analysis Zoology (People’s Education Press reprinted 1964 Edition) In addition to the introduction and conclusion, according to the evolution of animals from the low-level group to the high-level taxonomy into 12 parallel chapters, the first seven chapters are invertebrates. Protozoa are single-celled animals, coelenterates are two germ layers, symmetrical low-radiation multicellular animals, flat animals, linear animals are evolved to the three germ layers, symmetrical on both sides ... until vertebrates, embryonic development still to be repeated Both germ stages (gastrula). Therefore coelenterates occupy a more important position in the history of animal evolution.