Answers

2014-12-25T13:10:35+05:30
 a)Phylum-Chordata
b)this phylum is divided into 3 they are : urochordatd , cephalochordata , vertebrata 
In urochordata , notochord present only in larval tail.
In cephalochordata , it extends from head to tail region and is persisted throughout their life
In vertebrate  notochord is possessed during the embryonic period .
eg;- Ascidia,Branchiostoma,Myxine

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