Question

Some prosobranchs have only one _____________ in their mantle cavity.

a. Gill
b. Radula
c. Tentacle
d. Siphon

Answer 1

Some prosobranchs have only one gill in their mantle cavity, which helps them with respiration.

Step-by-step explanation:

In the context of the question, the term that belongs in the blank is Gill. Some prosobranchs, which are a type of mollusk, have only one gill in their mantle cavity. The gill helps these organisms with respiration by absorbing oxygen from the water they live in.