These interactive flashcards help IB Biology students Standard Level (SL) and Higher Level (HL) quickly review and memorize the essential definitions, formulas, and terms needed for success in IB Exams. Each card focuses on B3.1.3 Maintenance of concentration gradients at exchange surfaces in animals and is aligned with the IB Biology syllabus, ensuring focused revision on cell biology, genetics, and ecology. Students can test themselves anytime, anywhere, perfect for reinforcing tricky concepts, learning IB terminology, and committing formulas to memory. By using RevisionDojo's flashcards consistently, learners turn repetition into mastery and enter the exam with confidence.