[Campbell Biology P.733] According to the provided text, what is a defining characteristic o... | Practice Question

According to the provided text, what is a defining characteristic of the clade Ecdysozoa?

  • A: They are characterized by the presence of a trochophore larva stage.
  • B: They secrete external skeletons and undergo ecdysis (molting).
  • C: They possess a simple nervous system, a saclike gut, and no excretory system.
  • D: Their cells are supported and connected by collagen and other structural proteins located inside the cell membrane.

Explanation

The text states: 'The clade name Ecdysozoa refers to a characteristic shared by nematodes, arthropods, and some of the other ecdysozoan phyla... These animals secrete external skeletons exoskeletons ... As the animal grows, it molts, squirming out of its old exoskeleton... The process of shedding the old exoskeleton is called ecdysis.'