These comprehensive video lessons help IB Biology students Standard Level (SL) and Higher Level (HL) understand and master the essential concepts needed for success in IB Exams. Each video focuses on B3.1.3 Maintenance of concentration gradients at exchange surfaces in animals and is aligned with the IB Biology syllabus, ensuring focused learning on cell biology, genetics, and ecology. Students can watch and rewatch anytime, anywhere, perfect for visual learners, reinforcing complex concepts, and understanding IB methodology. By using RevisionDojo's video lessons consistently, learners build deep understanding and enter the exam with confidence.