Question

structures that are structurally similar but have different functions in related organisms are called ____.
a analogous
b homologous
c vestigial
d symmetrical

Explanation:

• Analogous structures: Have similar functions but different evolutionary origins (e.g., wings of insects and birds).
• Homologous structures: Share a common evolutionary origin (same embryonic origin) but may have different functions (e.g., human arm, bat wing, whale flipper).
• Vestigial structures: Remnants of organs/structures that had a function in an early ancestor (e.g., appendix in humans).
• Symmetrical structures: Refer to body symmetry (e.g., bilateral, radial) and not about evolutionary - structural relationships.

Since the question is about structurally similar (same evolutionary origin) but different functions, homologous structures fit.

Answer:

B. homologous