Which group forms the coelom by out-pocketing of the gut into mesoderm space?

Which group forms the coelom by out-pocketing of the gut into mesoderm space?

• A. Enterocoelomates
• B. Schizocoelomates
• C. Pseudocoelomates
• D. Acoelomates

Answer: (A)

Coelom formation by out-pocketing of the gut into mesoderm space is called enterocoely. In this pattern, the gut (archenteron) forms pouches that bud off into the surrounding mesoderm, creating coelomic cavities that are lined by mesoderm. Groups that develop this way are called enterocoelomates, a mode typical of deuterostomes such as chordates and echinoderms. By contrast, schizocoely forms the coelom when mesodermal blocks split to create cavities, pseudocoelomates have a cavity that is not fully lined by mesoderm (a false coelom between the mesoderm and endoderm), and acoelomates lack a true coelom altogether.

Coelom formation by out-pocketing of the gut into mesoderm space is called enterocoely. In this pattern, the gut (archenteron) forms pouches that bud off into the surrounding mesoderm, creating coelomic cavities that are lined by mesoderm. Groups that develop this way are called enterocoelomates, a mode typical of deuterostomes such as chordates and echinoderms.

By contrast, schizocoely forms the coelom when mesodermal blocks split to create cavities, pseudocoelomates have a cavity that is not fully lined by mesoderm (a false coelom between the mesoderm and endoderm), and acoelomates lack a true coelom altogether.