LIFE SCIENCE

Detailed explanation-1: -Notogenesis occurs during weeks three to four of embryonic development and is the formation of the notochord as part of the central region of the mesoderm (axial mesoderm). Notochord formation occurs in the mesoderm layer of an embryo during the gastrulation stages of development.

Detailed explanation-2: -The notochord is also known as chorda dorsalis. It is a rod-shaped cord of cells on the dorsal aspect of an embryo, defining the primitive axis of the body and serving as the center of development of the axial skeleton. It is the common factor of all chordates.

Detailed explanation-3: -One key consequence of gastrulation is the formation of the notochord, a distinct cylinder of mesodermal cells that extends along the midline of the embryo from anterior to posterior.