Question

Chordates are distinguished from non chordates by the presence of

• A. ventral nerve cord
• B. dorsal heart
• C. open circulatory system
• D. dorsal tubular nerve cord

Answer 1

The correct option is D dorsal tubular nerve cord

In chordates, the hollow or tubular nerve cord lies just above the notochord and extends in lengthwise throughout the body. The tubular nerve cord is present on the dorsal side of the chordate.
The ventral nerve cord of the invertebrate central nervous system is the functional equivalent of the vertebrate spinal cord.
The heart is ventral in position in chordates and dorsal in non chordates.
In chordates, the circulatory system is closed type.