If the radial nerve in an arm is cut,the podia in that arm lose coordination;if the circumoral nerve ring is cut,podia in all arms are uncoordinated and movement ceases.This indicates that
A)the hydraulic system is not involved in movement of tube feet.
B)the radial nerve controls the nerve ring.
C)part of the function of tube feet is hydraulic and part is controlled by the nerve stimulation.
D)water pressure in the hydraulic system is directly controlled by the nervous system.
E)the sea star is aware of the extent it is damaged and can change behaviors to compensate.

Question

Quizplus · Accepted Answer

The fact that cutting the radial nerve in an arm affects the coordination of the podia in that arm suggests that nerve stimulation plays a role in the movement of tube feet. However, cutting the circumoral nerve ring affects the coordination of podia in all arms, indicating that there is also a hydraulic component to the movement of tube feet. This suggests that tube feet movement involves both nerve stimulation and hydraulic pressure. Therefore, option C is the best choice. Options A, B, D, and E are not supported by the information given in the passage.

If the Radial Nerve in an Arm Is Cut,the Podia