Question

Cephalopod with an exoskeleton is
A) Pila
B) Chiton
C) Unio
D) Nautilus

Answer 1

A cephalopod is any individual from the molluscan class Cephalopoda, for example, a squid, octopus, cuttlefish, or nautilus. These solely marine creatures are portrayed by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the molluscan foot. The investigation of cephalopods is a part of malacology known as teuthology.

Complete answer:
Cephalopods got predominant during the Ordovician time frame, spoken to by primitive nautiloids. The class presently has two, just remotely related, surviving The Nautilus is a pelagic marine mollusc. They belong to the cephalopod family. They possess an external skeleton. This skeleton supports and protects its body. The body of these organisms is characterized by involute or convolute shells. These are generally smooth. The shells may be with compressed whorl sections, straight sutures, and a tubular siphuncle.

Nautiloidea, spoken to by Nautilus and Allonautilus. In the Coleoidea, the molluscan shell has been disguised or is missing, though, in the Nautiloidea, the outer shell remains. Around 800 living types of cephalopods have been distinguished. Two significant wiped out taxa are the Ammonoidea (ammonites) and Belemnoidea (belemnites).

The Nautilus is a pelagic marine mollusc. They have a place with the cephalopod family. They have an outer skeleton. This skeleton underpins and ensures its body. Their bodies are described by involute or tangle shells. These are commonly smooth. The shells perhaps with packed whorl areas, straight stitches, and a rounded siphuncle. Nautilidae, both surviving and wiped out, are described by involute or pretty much tangle shells that are commonly smooth, with packed or discouraged whorl segments, directly to twisted stitches, and a rounded, for the most part, focal siphuncle.

Thus the correct answer is option ‘D’, Nautilus.

Note: Nautilus contains six living species in two genera, the sort of which is the class Nautilus. In spite of the fact that it all the more explicitly refers to species Nautilus pompilius, the name chambered nautilus is likewise utilized for any of the Nautilidae.