Unit 8 · Environmental Biology
Trophic levels, food chains and food webs, why about 90% of energy is lost at each step, the three Eltonian pyramids, and the cycling of matter in ecosystems.
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.