Question

Notochord is persistent throughout the life in____________

• A. Protochordates
• B. Urochordates
• C. Cephalochordates
• D. All chordates

Answer 1

The correct option is C Cephalochordates

Phylum Chordata is classified into three subphyla as Urochordata, Cephalochordata and Vertebrata.
In Urochordata, the notochord is present only in larval stages and as the animal reaches the adult stage, notochord disappears. This is called retrogressive metamorphosis.
In Cephalochordata, the notochord persists throughout the life and extends from head to tail region.
In vertebrates, the notochord is replaced with vertebral column.