Limb bones within unrelated animals that have the same basic structures are considered

a. homologous structures.

b. vestigial structures.

c. embryological. End of exam

d. analogous structures.

Limb bones within unrelated animals that have the same basic structures are considered a. homologous structures. Homologous structures are similar structures shared by unrelated species. For example, birds and humans have the similar anatomy of limb bones. However, these are two unrelated groups of animals that share similar structures. Therefore, this is the example of homologous structures.