Among protostomes, which morphological trait has shown the most variation?

Question

Quizplus · Accepted Answer

The type of body cavity (coelom vs. pseudocoelom vs. no coelom) has shown the most variation among protostomes. This is because coelom formation can occur in different ways, leading to variations in its structure and function. It can arise from mesodermal cells or through the splitting of mesodermal tissue, and it can be lined with mesodermal cells or endodermal cells. These variations have led to the evolution of different body plans and lifestyles among protostomes. In contrast, the other options (type of symmetry, number of embryonic tissue types, and type of development) are relatively stable within protostomes, with only minor variations across different lineages.

Among Protostomes, Which Morphological Trait Has Shown the Most Variation