Question

In vertebrate notochord is
A. Persist throughout life
B. Is partially replaced by vertebral column
C. Is completely replaced by vertebral column
D. Is partially or wholly replaced by vertebral column

Answer 1

Vertebrate is an animal with the spinal cord surrounded by the cartilage or bone. They also have an alimentary canal which ends in anus and they have a mouth in the anterior portion.

Complete answer:
The notochord is the defining structure of the chordates and essential role in the vertebrate development. It serves as a source of midline signals that pattern surrounding tissues and has a major skeletal element of a developing embryo. Genetic and every logical study over the past decade have informed us about the development of the function of the notochord.

Invertebrate the notochord arises from the dorsal organiser. Originally identified by Spemann and Mangold in amphibians, the directional organiser is a reason of a vertebrate that when transplanted into the prospective little plentiful region of a host embryo induces the formation of a second embryonic axis, while only contributing to notochord.

What is oriented head to tail and is found between the digestive tube and the nerve cord. Since it is composed to stick to tissue it allows for skeletal support for the organism. In certain codes like the lamprey and the sturgeon, the notochord remains there for life.

Therefore, from the above explanation, the correct option is (D) Is partially or wholly replaced by the vertebral column.

Note: In vertebrates suggest your months a more Complex backbone appear with only a portion of notochord remaining has backbone full reforms the disc in back is where the pieces of notochord are found as a sort of gelatinous used material.