Schizocoelomates are associated with which type of cleavage?

Schizocoelomates are associated with which type of cleavage?

• A. Spiral
• B. Radial
• C. No cleavage
• D. Bilaterally symmetric cleavage

Answer: (A)

This question tests how the way embryos divide during early development (cleavage) relates to how the body cavity forms in schizocoelomates. Schizocoelomates form their coelom by schizocoely, which means the coelom develops from splitting of the mesoderm. This pattern is characteristic of many protostomes, and it is typically paired with spiral cleavage, where the cleavage planes are oblique to the axis and yield a spiral arrangement of blastomeres with determinate cell fates. In contrast, radial cleavage is associated with deuterostomes and enterocoely, where the coelom forms from pouches of the gut. So spiral cleavage best fits the schizocoelomate mechanism, making it the correct association.

This question tests how the way embryos divide during early development (cleavage) relates to how the body cavity forms in schizocoelomates. Schizocoelomates form their coelom by schizocoely, which means the coelom develops from splitting of the mesoderm. This pattern is characteristic of many protostomes, and it is typically paired with spiral cleavage, where the cleavage planes are oblique to the axis and yield a spiral arrangement of blastomeres with determinate cell fates. In contrast, radial cleavage is associated with deuterostomes and enterocoely, where the coelom forms from pouches of the gut. So spiral cleavage best fits the schizocoelomate mechanism, making it the correct association.