[Campbell Biology P.745] Which of the following statements correctly differentiates between ... | Practice Question

Which of the following statements correctly differentiates between free-living planarians and parasitic trematodes based on the provided text?

  • A: Unlike planarians, trematodes always reproduce sexually, lacking asexual stages in their life cycles.
  • B: Trematodes are characterized by the presence of suckers for attachment to hosts, a feature generally absent in free-living planarians.
  • C: Both planarians and trematodes typically have complex life cycles involving multiple intermediate hosts before reaching their final host.
  • D: Planarians are capable of evading host immune systems by mimicking surface proteins, a strategy also observed in trematodes.

Explanation

The text explicitly states for parasitic rhabditophorans which include trematodes that 'Many have suckers that attach to the internal organs or outer surfaces of the host animal.' Free-living planarians do not possess suckers for parasitic attachment. Furthermore, the ability to evade host immune systems by mimicking surface proteins is specifically mentioned for blood flukes trematodes , not planarians.