Question

Despite their differences in appearance, all bony fish have common ancestors. their fins develop from similar structures and usually have a prescribed number of bones. because of this, the large rudder-like dorsal fin of a sailfish, the poisonous dorsal fin of a catfish, and the tiny reduced dorsal fin of a puffer fish are said to be ________ structures.

Answer 1

C

Step-by-step explanation:

Homologous structures. These are traits, though different in appearance and function, that are derived from the same ancestral trait during development.

Answer 2

They are homologous structures

This means that they share the same structure or originate from the same original structure, which is exactly what you described. They don't have to be the same however, being similar is enough for it to be called homologous.