[Campbell Biology P.764] Which statement correctly describes members of the clade Crinoidea ... | Practice Question

Which statement correctly describes members of the clade Crinoidea sea lilies and feather stars , according to the text?

  • A: Sea lilies crawl using flexible arms and have a mouth directed downwards.
  • B: Feather stars are attached to the substrate by a stalk and use their arms for locomotion.
  • C: Both sea lilies and feather stars use their arms in suspension feeding, but sea lilies are attached by a stalk while feather stars crawl.
  • D: Crinoidea is a recently evolved group with significantly changed morphology compared to their fossilized ancestors.

Explanation

The text states that 'Sea lilies live attached to the substrate by a stalk; feather stars crawl about by using their long, flexible arms. Both use their arms in suspension feeding.' It also notes that Crinoidea is an 'ancient group whose morphology has changed little over the course of evolution'.