Question

Many biologists were surprised by molecular data supporting the hypothesis that ctenophores are the sister group to all other animals. what anatomical and morphological features of ctenophores are conventionally thought to support a close relationship with bilaterian animals? (select all that apply.) the rudimentary flow through gut the presence of what many take to be a rudimentary mesoderm the presence of an outer epithelium the presence of gelatinous material in the interior of the ctenophore body

Answer 1

The answer is ‘the presence of what many take to be a rudimentary mesoderm’. One of the classifications for bilaterians is their characteristic germ layers. These germ layers include the ectoderm, mesoderm, and endoderm. Ctenophores had previously been thought to lack a mesoderm, but recently an elementary layer has been discovered between the endoderm and ectoderm, which could serve as a mesoderm.