Question

what is a notochord mean please explain

Answer 1

A cartilaginous skeletal rod supporting the body in all embryonic and some adult chordate animals.

OR

a rodlike cord of cells that forms the chief axial supporting structure of the body of the lower chordates, as amphioxus and the cyclostomes, and of the embryos of the vertebrates

Answer 2

In anatomy, the notochord is a flexible rod made out of a material similar to cartilage. If a species has a notochord at any stage of its life cycle, it is, by definition, a chordate. In vertebrates the notochord becomes part of the vertebral column. The notochord lies along the anteroposterior ("head to tail") axis, is usually closer to the ventral than the dorsalsurface of the animal, and is composed of cells derived from the mesoderm. The notochord has been observed to have many functions including developmental functions. The most commonly cited functions are as a site of muscle attachment, vertebral precursor, and as a midline tissue that provides signals to the surrounding tissue during development.