IB DP Biology SL Prediction Paper 1A and 1B for 2025 Exams
IB DP Biology SL Prediction Paper 1A and 1B- April/May 2025 Exam
IB DP Biology SL Prediction Paper 1A and 1B: Prepare for the IB exams with subject-specific Prediction questions, model answers. All topics covered.
Prepared by IB teachers: Access our IB DP Biology SL Prediction Paper 1A and 1B with model answer. Students: Practice with exam-style papers for IB DP Biology SL Exam
Question 1
The diagrams show the structure of leucine, an essential amino acid. Which diagram highlights the part of leucine that distinguishes it from other amino acids?
▶️ Answer/Explanation
Answer: B
Explanation: The R-group (side chain) varies between amino acids and determines their unique properties. All amino acids share the same amino group, carboxyl group, and alpha carbon structure.
Question 2
What is a common feature of enzymes?
▶️ Answer/Explanation
Answer: A
Explanation: All enzymes react with specific substrates (definition of enzyme). Some enzymes increase reaction rates (B incorrect). Not all are secreted (C incorrect). Enzymes have active sites that substrates bind to, not vice versa (D incorrect).
Question 3
What distinguishes aerobic respiration from anaerobic respiration in humans?
▶️ Answer/Explanation
Answer: D
Explanation: CO₂ is only produced in aerobic respiration (Krebs cycle). Mitochondria are used in both (A incorrect). Aerobic yields more ATP (B incorrect). Both can use glucose (C incorrect).