[Campbell Biology P.762] Which of the following accurately describes the primary functions o... | Practice Question

Which of the following accurately describes the primary functions of tube feet in sea stars and their method of consuming bivalves?

  • A: Tube feet primarily function in sensory perception and waste excretion; sea stars open bivalves by dissolving their shells with acid.
  • B: Tube feet are used for locomotion and feeding; sea stars evert their stomach into the bivalve's shell for external digestion.
  • C: Tube feet are responsible for gas exchange and excretion; sea stars use strong suction to pull open bivalve shells.
  • D: Tube feet secrete digestive enzymes; sea stars consume bivalves whole and digest them internally.

Explanation

The text states: 'Unique to echinoderms is the water vascular system, a network of hydraulic canals branching into extensions called tube feet that function in locomotion and feeding.' And later: 'The sea star then turns part of its stomach inside out, everting it through its mouth and into the narrow opening between the halves of the bivalve's shell. Next, the digestive system of the sea star secretes juices that begin digesting the mollusc within its own shell.'