While looking at some seawater through your microscope, you spot the egg of an unknown animal. Which of the following tests could you not use to determine whether the developing organism is a protostome or a deuterostome?
A) See whether the coelom is formed from a split in the mesoderm or from mesodermal pockets pinched off the gut.
B) See whether the animal exhibits spiral cleavage or radial cleavage during early development.
C) See whether the pore formed during gastrulation becomes the mature animal's mouth or its anus.
D) See whether the ectoderm forms the mature animal's skin/exoskeleton or nervous system.

Question

Quizplus · Accepted Answer

The distinction between protostomes and deuterostomes is not based on whether the ectoderm forms the mature animal's skin/exoskeleton or nervous system, as both groups can have these structures derived from the ectoderm. The key differences involve patterns of cleavage, coelom formation, and the fate of the blastopore.

While Looking at Some Seawater Through Your Microscope, You Spot