Exchange of respiratory gases in enteropneusts is accomplished at the pharyngeal slits and by
A)diffusion in alveolar lungs.
B)active transport in the tracheal system.
C)diffusion across the body wall.
D)facilitated diffusion in dermal branchiae.
E)facilitated diffusion in book gills.

Question

Quizplus · Accepted Answer

Enteropneusts do not possess specialized respiratory organs like lungs or gills. Instead, they exchange respiratory gases by simple diffusion across their body wall and also through the pharyngeal slits. These pharyngeal slits are openings in the pharynx (throat) which function in feeding as well as gaseous exchange. Therefore, option C, diffusion across the body wall, is the best choice.

Exchange of Respiratory Gases in Enteropneusts Is Accomplished at the Pharyngeal