Question

The structure which evolved first within the animal lineage leading to humans is

• A. Bone
• B. Cranium
• C. Jaws
• D. Notochord
• E. Vertebrae

Answer 1

The correct option is D Notochord

Chordates are deuterostome coelomates having bilateral symmetry and are supposed to be evolved from deuterostome ancestors with development of notochord, dorsal, tubular nerve cord, pharyngeal slits and post anal tail; the features that are found in all the chordates. Later, evolution of cranium and vertebral column led to evolution of vertebrates.

Therefore, the correct answer is option D.