Question

All of the following are either structures or characteristics of members of the Class Bivalvia of the Phylum Mollusca except

A. The mantle
B. A radula
C. A shell
D. Gills
E. Open circulation

Answer 1

Answer: B. radula

Step-by-step explanation:

the rest of the answers are characteristics and members of Bivalvia and the only one wasn't a characteristic was B

Answer 2

Bivalves in Class Bivalvia do not have a radula; they are filter-feeders that use gills for feeding and respiration, characterized by a mantle, a shell, and open circulation. So the correct option is B.

Step-by-step explanation:

The question asks which of the listed options is not a structure or characteristic of members of the Class Bivalvia in the Phylum Mollusca. Bivalves are known for several distinctive attributes, including a mantle that secretes their shell, a shell for protection, gills (ctenidia) for respiration, and open circulation. However, unlike other mollusks, bivalves do not have a radula, which is typically a rasping feeding organ. Therefore, the correct answer to the question is B. A radula since bivalves are filter-feeders that lack this structure.