Question

why do whales possess a functional femur? they are evolving hind limbs and will eventually walk on land. they descended from organisms that walked on land. whales do not have a femur.

Explanation:

• Option 1: Whales are fully aquatic and have no evolutionary trend to return to land - this is incorrect.
• Option 2: Whales are descendants of terrestrial tetrapods. The functional femur is a vestigial structure from their land - dwelling ancestors, so this is correct.
• Option 3: Whales do have a femur (even if reduced/functional in a vestigial sense), so this is incorrect.

Answer:

B. They descended from organisms that walked on land.