What do you mean by 'Notochord'? Explain.

Explanation

(i)Notochord is a long rod-like supporting structure present on the dorsal side of animal body.
(ii) It keeps the nerve tissue isolated from the remaining body.
(iii) It provides place for the muscles to attach for ease of movements.
(iv) Animals which do not have notochord are called Non-chordates.
(v) In Hemichordates, notochord is present in proboscis region only.
(vi) In Chordates, notochord is present in the body during any developmental stage.
(vii) In Urochordates, it is present only in tail region of larvae.
(viii) In Cephalochordates, notochord is present throughout the body length.
(ix) In Vertebrates, notochord is replaced by vertebral column.