Phylum : Platyhelminthes (Flat worms), its classification and characteristics

multicellular, triploblastic, bilaterally symmetrical. first animals to have organ-system grade of body organization. body is dorsoventrally flattened so called flat worms. size varies from less than mm and more than 10-15 metres. mostly parasitic, few are free living and are found in water or damp soil. parasitic forms have hooks and suckers to stick to … Read more

Differences between vertebrates and invertebrates

S.N Vertebrates Invertebrates 1. They have backbone or vertebral column. They do not have backbone or vertebral column. 2. They are the most organized animals on the earth. They are not organized as vertebrates. 3. They consist of single phylum. They consist of eight phylum. 4. They have internal skeleton. Internal skeleton absent. 5. They … Read more