Practice question

Contrasting with cnidarians possessing blind sac gastrovascular cavity with single opening, ctenophores exhibit through gut considered complete alimentary canal with distinct mouth at oral pole leading to pharynx stomach and canals extending meridionally beneath comb rows distributing nutrients and two aboral anal pores near apical organ expelling residues. Food enters via mouth after capture digested in stomach extracellularly intracellularly via phagocytes circulated through canals. Presence anal pores allows separate egestion enabling unidirectional processing more efficient than cnidarian blind gut considered advanced though debated homology with bilaterian anus and through gut evolution in early metazoans.