Question

The following diagram shows the relationships between certain types of organisms. The red lines represent a common ancestor that was the first organism to have the trait listed. For example, sea stars do not have spinal cords, but the organisms that come after do have a spinal cord.



Seahorses have spinal cords, jaws, and bones, but they do not have lungs. Which of the organisms in the diagram is most closely related to seahorses?
A.
lamprey
B.
bullfrog
C.
shark
D.
perch

Answer 1

D. perch

Seahorses are bony, jawed vertebrates without lungs. Perch are also bony (osteichthyan), jawed vertebrates without lungs, so they share the most recent common ancestor with the trait "bones." Lampreys are jawless, sharks are cartilaginous (no bones), and bullfrogs have lungs.