Unit 5 · Animal Form and Function
The features of an efficient respiratory surface and how gas exchange is achieved through the body surface, gills, tracheae and lungs, with the counter-current system of fish and the one-way flow of birds.
Deshapriya Senevirathne. B.Sc. (Hons) Biology Special, University of Peradeniya — graduated with a class pass. All the content and lessons in A/L Biology on Paadama are reviewed by Deshapriya Senevirathne, and the lessons are taught by him.