AIIMS 2017 Biology Chordates MCQ Question

Retrogressive metamorphosis is a phenomenon observed in certain vertebrates, particularly in some species of amphibians, where the adult form is simpler and less developed than the larval form. In contrast, urochordates, which include tunicates, undergo a different type of metamorphosis where they transition from a free-swimming larval stage to a sessile adult form, but this is not classified as retrogressive. Invertebrates and chordates encompass a wide range of organisms, but they do not specifically exhibit retrogressive metamorphosis in the same manner as certain vertebrates. Thus, retrogressive metamorphosis is primarily associated with vertebrates, making option A the most accurate choice.