Question

The ascidian tapole larva undergoes

• A. Progressive metamorphosis
• B. Retrogressive metamorphosis
• C. Partial metamorphosis
• D. Complete metamorphosis

Answer 1

The correct option is B Retrogressive metamorphosis

Metamorphosis is the phenomena in which there are changes which transform the organism form its juvenile stage to adult stage. In the case of retrogressive metamorphosis, the larva possesses the advanced features which get lost during the development. The adult is sedentary or degenerated with the primitive characters. Retrogressive metamorphosis is a characteristic of ascidians (Urochordata or Tunicata). The progressive, active and alert larva metamorphoses into a retrograde and sedentary bag-like creatures. The adult remains attached to a rocky substratum all their lives and use a current of water passing through their large and perforated pharynx to collect microorganisms on which they feeds.

Thus, the correct answer is option B.