In museum study, a clam feeds by filtering water and does not scrape food from surfaces. The specimen or feature is best linked with:

Correct Answer: A

absence of radula

Bivalves generally lack a radula because they feed by filtering suspended particles with their gills. This contrasts with gastropods, where the radula is commonly used for scraping. This MCQ belongs to the Bivalvia topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.