Acoelomates are Characterized By

Question

Acoelomates are characterized by
A)the absence of a brain.
B)the absence of mesoderm.
C)deuterostome development.
D)a coelom that is not completely lined with mesoderm.
E)a solid body without a cavity surrounding internal organs.

Accepted Answer

Acoelomates are animals that lack a coelom, a fluid-filled body cavity surrounding internal organs. As a result, they have a solid body without a cavity surrounding their internal organs. Acoelomates do have a rudimentary form of a nervous system, so choice A is incorrect. They also do not undergo deuterostome development, so choice C is incorrect. Choice B is also incorrect, as acoelomates do have mesoderm, but it is not organized into a coelom. Finally, choice D is incorrect because acoelomates lack a coelom entirely.