Which of these statements, if accurate, would support the claim that the ancestral cnidarians had bilateral symmetry?
A) Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects.
B) Cnidarians have fewer Hox genes than bilaterians.
C) All cnidarians are acoelomate.
D) The presence of collar cells.

Question

Quizplus · Accepted Answer

The presence of anterior-posterior and left-right aspects in cnidarian larvae suggests bilateral symmetry, as these are characteristic of bilaterally symmetrical organisms.

Answer: D
 Collar cells (also known as choanocytes) are found in some cnidarians, such as sponges, which are considered to be primitive animals with radial symmetry. Therefore, the presence of collar cells in cnidarians suggests that they may have evolved from ancestors with bilateral symmetry.

Which of These Statements, If Accurate, Would Support the Claim