In higher chordates, such as vertebrates, the notochord is replaced by the vertebral column or backbone during development. The notochord provides structural support in early embryonic development but is eventually replaced by the more complex vertebral column, which provides greater support and protection for the spinal cord.
The notochord is a cellular chord that develops by transformation of the notochordal process. The notochord will eventually become the nucleus pulposis of each intervertebral disk.
formation of notochordal process :
the primitive streak is formed from a linear band of cells called epiblasts which first appears caudally then grows cranially.At the cranial end its cells proliferate to form primitive node.
Mesenchymal cells migrate from the primitive knot to form a midline cellular cord known as the notochordal process.
The firm flexible rod found in the dorsal area of chordates is called the notochord. It provides support and structure to the body, and is present during early development in all chordates. In most vertebrates, including humans, the notochord is eventually replaced by the vertebral column.
Three structures that all chordates have in common are a notochord (flexible rod providing structural support), a dorsal hollow nerve cord (which develops into the central nervous system), and pharyngeal slits or pouches (which can be used for filter feeding or respiration).
The notochord is the flexible supporting structure found only in chordates. It is a rod-like structure that runs along the length of the body, providing support and allowing for some degree of movement.
The long supporting rod that runs through the body of chordates is called the notochord. It provides structural support and helps with body movement. In some species, the notochord is replaced by the vertebral column during development.
Chordates are animals that possess a notochord at some stage of their development, while vertebrates are a subgroup of chordates that have a backbone or spinal column made of vertebrae. Therefore, all vertebrates are chordates, but not all chordates are vertebrates.
a notochord.
notochord.
Notochord
The firm flexible rod found in the dorsal area of chordates is called the notochord. It provides support and structure to the body, and is present during early development in all chordates. In most vertebrates, including humans, the notochord is eventually replaced by the vertebral column.
chordates
Three structures that all chordates have in common are a notochord (flexible rod providing structural support), a dorsal hollow nerve cord (which develops into the central nervous system), and pharyngeal slits or pouches (which can be used for filter feeding or respiration).
notochord.
Notochord- a flexible rod that supports a chordates back.notochord is a stuff rod of conective tissue.it is present in the mid_dorsal region of the embryo.in the lower chordates .the notochord is present throughout of life but in vertebrates .the vertebral column or bacjbone replaces it.
Hagfish are chordates and craniates, but they are not vertebrates. This is because they have a skull and notochord but lack vertebrae.
The presence of a notochord at some point in the organism's development is one of the characteristics that distinguishes chordates from other phyla. Without it, I'm not sure if the organism would be considered a chordate.
Chordates are not vertebrates because although some vertebrates are chordates theres many reasons why chordates arent vertebrates.the first reason is because chordates consist of a notochord or a dorsal nerve.
The key developmental event that marks the evolution of chordates is called neurulation. This process involves the formation of the notochord and dorsal nerve cord during embryonic development, which are defining features of chordates. Notochord provides support, while the dorsal nerve cord eventually develops into the spinal cord and central nervous system in higher vertebrates.