Answer: The following features classifies exclusively the members of Chordata:
a.) a postanal tail during embryonic development
b.) pharyngeal pouches during embryonic development
d.) a notochord on the dorsal side of the gut in the early embryo
f.) a hollow nerve cord
Therefore the correct options are a,b,d and f
Explanation:
The echinodermata and chordata phylum are both found in the kingdom animalia but possesses different features. The chordates has some features that helps distinguish it from other phylum and these include:
--> Pharyngeal pouches: these are openings to the exterior from the pharynx, the region just posterior to the mouth. In aquatic environment, they develop into pharyngeal slits that allow for the exit of water that enters the mouth during feeding.
--> a postanal tail during embryonic development
--> A notochord: The chordates possess a flexible rod of tightly packed cells called notochord which is located at the dorsal side of the gut in the early embryo.
--> A hollow nerve cord: This is a tubular nerve cord that is derived from ectoderm that rolls into a hollow tube during embryonic development.
These features of chordata has played a significant role in the evolution of the phylum. This is so because the vertebrata is a subphylum of the chordates. For example, the nerve cord found in most chordate embryos develops into the brain and spinal cord, which comprise the central nervous system seen in vertebrates.
