Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
Monoplacophora
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Scaphopoda
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Cephalopoda
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is A Amphineura Class Amphineura are all marine. There is present a non-ganglionated nerve ring around the mouth with two pairs of interconnected nerve cord. Head is reduced and without eyes and tentacles. The shell consists of a row of 8 plates. For example, Chiton which is commonly known as the coat of mail shell.
Monoplacophora includes primitive mollusc, Neopilina and its shell is spoon or cup-shaped.
Scaphopoda includes Dentalium which has a worm-like a body enclosed in a curved tubular shell open at both ends.
In cephalopods, the shell is often internal or reduced. It may be external as in Nautilus or absent as in Octopus.