Question

Vertebral column develops from
(a)Notochord
(b)Nerve cord
(c)Mesoderm
(d)Endoderm

Answer 1

Vertebral column is known to develop from a flexible rod-like structure of mesodermal cells that is the principal longitudinal structural element of chordates and of the early embryo of vertebrates. These are only found in the phylum Chordata, a group of animals that includes humans.

Complete answer:
The vertebral column develops from a flexible rod formed of a material similar to cartilage known as Notochord. They are present at the embryonic stage of vertebrates and then they transform to the vertebral column. If a species has a notochord at any stage of its life cycle, it is, by definition, a chordate. The notochord is composed of cells derived from the mesoderm. In vertebrates, Notochord is only embryonic, and in the adult, it gets partially or completely replaced by the vertebral column. Embryonic Notochord never extends forward beyond the level of fore-brain. The development of the vertebral column is always accompanied by the development of the cranium or the braincase. Hence vertebrates are also called craniates.

Additional Information: -Vertebrates are the Chordates with Vertebral column or the backbone in the adult, partially or completely replacing the embryonic notochord.
-Vertebrates have, well developed nervous system and brain-case.
-There is also well developed cartilaginous or bony endoskeleton.
So, the correct answer is 'Notochord'.

Note: -Some animals traditionally included under the subphylum Vertebrata have no vertebrae in the adult.
-Hag fishes and lampreys are examples of such animals. Jag fishes lack vertebral elements, and lampreys have only cartilaginous rudiments of vertebrae.
-Full formed vertebrae with true centrum are only found in jawed vertebrates.