Question

Identify the incorrect statements.
(I) Members of Gastropoda exhibit torsion.
(II) Aristotle lantern is present in sea urchins.
(III) Anthozoans are medusa forms.
(IV) Diplopoda includes scorpions.

• A. II, III
• B. III, IV
• C. II, IV
• D. I, II

Answer 1

Answer: (B)

III, IV

The gastropods possess an asymmetrical body. Torsion is the rotation of the visceral mass, mantle and shell 180 degree with respect to the head and foot of the gastropod. This brings the mantle cavity and anus to an anterior position above the head, thereby causing asymmetry in gastropods. Aristotle's lantern is a complex arrangement of muscles and calcareous teeth and plates forming an organ in most echinoids, including sea urchins, functioning in mastication. Anthozoa is a largest class of Cnidaria. They do not have medusa stage in their development. They shows asexual polyploid form only. Class Diplopoada includes Millipedes. Most millipedes are slower than centipedes, and they feed on leaf litter and detritus.

Thus, the correct answer is option B.