Question

Which of the following characteristics occurs in urochordate larva but is/are lost during retrogressive metamorphosis?

• A. Loss of notochord
• B. Loss of tail
• C. Experience reduction of nervous system to a visceral ganglion
• D. All of the above

Answer 1

The correct option is D All of the above

• Metamorphosis is the phenomenon in which some changes transform the organism from its juvenile stage to the adult stage.
• In retrogressive metamorphosis, the larva possesses the advanced features that get lost during the development.
• The adult is sedentary or degenerated with the primitive characters.
• The Urochordate larva shows advanced chordate characters which get lost during metamorphosis.
• The tail present in the larvae for swimming gets lost.
• There is a loss of the rodlike notochord in the tail.
• There is a hollow nerve cord that forms the brain at the anterior end of the larvae.
• The hollow nerve cord in adults gets reduced to form a solid nerve ganglion.

Thus, the correct answer is option D.