Final answer:
During the embryonic stage, chordates share three characteristics: notochord, dorsal hollow nerve cord, and pharyngeal slits.
Step-by-step explanation:
During the embryonic stage, chordates, which include vertebrates like mammals, birds, reptiles, amphibians, and fish, share three key characteristics. Firstly, the presence of a notochord, a flexible rod-like structure, provides structural support. Second, a dorsal hollow nerve cord develops, forming the nervous system and spinal cord.
Third, pharyngeal slits or pouches appear in the pharyngeal region, facilitating filter-feeding in aquatic species or developing into structures like gills or parts of the ear and throat in other chordates. These embryonic features are fundamental to the chordate developmental plan, reflecting the evolutionary relationships among diverse members of this animal phylum.
Your question is incomplete, most probably the complete question is:
What are three characteristics that chordates share during the embryonic stage?