Theoretical 1 Start Timed Attempt → 🏆 Leaderboard Theoretical 1 Exam + Official Answer Key Community Solutions (unofficial) All Topics Aggression, Territoriality & Social Structure Biological Rhythms Biomolecular Analytical Techniques Carbohydrate Chemistry & Biology Cardiovascular Physiology Cell Junctions, Extracellular Matrix & Cell Death Coevolution & Species Interactions Comparative Thermoregulation DNA Structure & Replication Ecology Endocrine System Physiology Enzyme Kinetics & Regulation Evolutionary Developmental Biology (Evo-Devo) Extranuclear & Non-Mendelian Inheritance Fish & Amphibian Anatomy Flower Anatomy & Reproductive Structures Human Circulatory System Human Integumentary System Human Sensory Organs Human Skeletal System Immune Physiology Leaf Anatomy Locomotion & Energetics Mammalian Comparative Anatomy Mating Systems & Sexual Selection Mineral Nutrition & Nutrient Uptake Molecular Evolution & Neutral Theory Natural Selection: Modes & Fitness Nervous System Physiology Nucleotide & Nucleic Acid Chemistry Pedigree Analysis & Human Genetic Disorders Plant Body Plans Across Major Lineages Plasma Membrane Structure & Transport Protein Structure, Folding & Function Recombinant DNA & Biotechnology Techniques Respiratory Physiology Root Anatomy Secondary Growth & Wood Anatomy Stem Anatomy Water Transport & Transpiration All Easy Medium Hard Q1 Alfalfa Mosaic Virus, m6A Demethylation & Viral Replication Protein Structure, Folding & Function Biomolecular Analytical TechniquesMedium IBO·2022·Q1 — ptsPDF Q2 Enzyme Kinetics, Time to Completion vs Temperature Enzyme Kinetics & RegulationMedium IBO·2022·Q2 — ptsPDF Q3 Amylase Activity, Starch Hydrolysis at 50-70°C Enzyme Kinetics & Regulation Carbohydrate Chemistry & BiologyMedium IBO·2022·Q3 — ptsPDF Q4 Enzyme Inhibition, Substrate Concentration vs Rate Curves Enzyme Kinetics & RegulationMedium IBO·2022·Q4 — ptsPDF Q5 Meselson-Stahl Experiment, DNA Replication Modes DNA Structure & ReplicationHard IBO·2022·Q5 — ptsPDF Q6 Cell Membrane Transport, Arrows X, Y, Z Plasma Membrane Structure & TransportEasy IBO·2022·Q6 — ptsPDF Q7 Apoptosis, p53/Bax/Bcl-2 Pathway Under Hypoxia Cell Junctions, Extracellular Matrix & Cell DeathMedium IBO·2022·Q7 — ptsPDF Q8 Ethidium Bromide, DNA Binding and Intercalation DNA Structure & Replication Nucleotide & Nucleic Acid ChemistryMedium IBO·2022·Q8 — ptsPDF Q9 Organ-on-a-Chip, Lung-on-a-Chip & Pulmonary Oedema Model Cell Junctions, Extracellular Matrix & Cell Death Recombinant DNA & Biotechnology TechniquesMedium IBO·2022·Q9 — ptsPDF Q10 3D Bioprinting, Cell Viability, Bioluminescence, and Confocal Imaging Recombinant DNA & Biotechnology Techniques Biomolecular Analytical TechniquesMedium IBO·2022·Q10 — ptsPDF Q11 Heart Decellularization, Fish vs. Rat Cannulation Human Circulatory System Recombinant DNA & Biotechnology TechniquesMedium IBO·2022·Q11 — ptsPDF Q12 iPSC/hESC Cardiomyocyte Grafts After Myocardial Infarction Recombinant DNA & Biotechnology Techniques Cardiovascular PhysiologyHard IBO·2022·Q12 — ptsPDF Q13 3D Skin Substitute, Layered Tissue Engineering Recombinant DNA & Biotechnology Techniques Human Integumentary SystemMedium IBO·2022·Q13 — ptsPDF Q14 Water Potential, Osmosis Between Three Plant Cells Water Transport & TranspirationMedium IBO·2022·Q14 — ptsPDF Q15 Plant Life Cycle, Heterospory and Gametophyte Forms Plant Body Plans Across Major LineagesMedium IBO·2022·Q15 — ptsPDF Q16 Flower Structure, Symmetry, Pollination, and Calyx Flower Anatomy & Reproductive StructuresEasy IBO·2022·Q16 — ptsPDF Q17 Plant Organ Modifications, Shoot vs. Leaf Origin Stem Anatomy Leaf AnatomyMedium IBO·2022·Q17 — ptsPDF Q18 Mycorrhizal Symbiosis, Ecto-, Endo-, and Ectendomycorrhiza Root Anatomy Mineral Nutrition & Nutrient UptakeEasy IBO·2022·Q18 — ptsPDF Q19 Plant Life Cycles, Water-Dependent Fertilization Plant Body Plans Across Major LineagesMedium IBO·2022·Q19 — ptsPDF Q20 Tree Age Estimation, Annual Ring Growth Secondary Growth & Wood AnatomyHard IBO·2022·Q20 — ptsPDF Q21 Biological Samples, Identifying Diverse Organisms Biomolecular Analytical TechniquesMedium IBO·2022·Q21 — ptsPDF Q22 Social Stress Response in Mice, Dominance Hierarchy Aggression, Territoriality & Social StructureMedium IBO·2022·Q22 — ptsPDF Q23 Gut Microbiome, Bacterial Crossing of the Blood-Brain Barrier Nervous System Physiology Immune PhysiologyHard IBO·2022·Q23 — ptsPDF Q24 Comparative Liver Anatomy, Zebrafish vs. Human Fish & Amphibian Anatomy Mammalian Comparative AnatomyMedium IBO·2022·Q24 — ptsPDF Q25 Oxytocin and Cortisol, Touch vs. Voice Contact in Girls Endocrine System PhysiologyMedium IBO·2022·Q25 — ptsPDF Q26 Cardiac Cycle, Valve Timing and Pressure Changes Cardiovascular PhysiologyMedium IBO·2022·Q26 — ptsPDF Q27 Saiga Antelope, Nose Adaptations for Cold, Dust, and Signalling Comparative Thermoregulation Mating Systems & Sexual SelectionEasy IBO·2022·Q27 — ptsPDF Q28 Carbon Dioxide Transport in the Blood Respiratory PhysiologyMedium IBO·2022·Q28 — ptsPDF Q29 The Bohr Effect, Oxygen-Haemoglobin Dissociation Respiratory PhysiologyMedium IBO·2022·Q29 — ptsPDF Q30 Bone Marrow Conversion, Red vs. Yellow Marrow With Age Human Skeletal SystemMedium IBO·2022·Q30 — ptsPDF Q31 Retina Cell Layers, Direction of Light and Cell Types Human Sensory OrgansMedium IBO·2022·Q31 — ptsPDF Q32 Shiverer Mutation, Optic Nerve Myelin Nervous System PhysiologyMedium IBO·2022·Q32 — ptsPDF Q33 Dormouse Litters, Growth Rate and Energy Intake Locomotion & EnergeticsMedium IBO·2022·Q33 — ptsPDF Q34 Cichlid Fish, Anal Fin Egg-Spot Signalling Mating Systems & Sexual SelectionMedium IBO·2022·Q34 — ptsPDF Q35 Ninespine Stickleback, Sexual Dimorphism and Sneaker Males Mating Systems & Sexual SelectionMedium IBO·2022·Q35 — ptsPDF Q36 Aethia cristatella, Courtship Display on Rocks Aggression, Territoriality & Social Structure Mating Systems & Sexual SelectionMedium IBO·2022·Q36 — ptsPDF Q37 ABO Blood Groups, H Antigen and the Bombay Phenotype Pedigree Analysis & Human Genetic DisordersHard IBO·2022·Q37 — ptsPDF Q38 Modes of Natural Selection, Frequency Distribution Curves Natural Selection: Modes & FitnessMedium IBO·2022·Q38 — ptsPDF Q39 Mutation Rates, Asexual vs. Sexual Yeast Populations Molecular Evolution & Neutral TheoryHard IBO·2022·Q39 — ptsPDF Q40 Elephants, LIF6, and Cancer Resistance Molecular Evolution & Neutral Theory Cell Junctions, Extracellular Matrix & Cell DeathMedium IBO·2022·Q40 — ptsPDF Q41 Angelman Syndrome, Genomic Imprinting Pedigree Pedigree Analysis & Human Genetic Disorders Extranuclear & Non-Mendelian InheritanceHard IBO·2022·Q41 — ptsPDF Q42 Thyrocyte Adenylyl Cyclase, TSH and VIP/PACAP Pathways Endocrine System PhysiologyHard IBO·2022·Q42 — ptsPDF Q43 Giraffe FGFRL1, Cardiovascular and Skeletal Adaptations Cardiovascular Physiology Molecular Evolution & Neutral TheoryMedium IBO·2022·Q43 — ptsPDF Q44 Macromutations and Morphogenesis, A1/A2/M Gene Model Evolutionary Developmental Biology (Evo-Devo)Hard IBO·2022·Q44 — ptsPDF Q45 Drosophila Color Preference and Circadian Activity Biological RhythmsMedium IBO·2022·Q45 — ptsPDF Q46 Three-Toed Sloth Fur Ecosystem, Moths, Algae, and Fungi Coevolution & Species InteractionsMedium IBO·2022·Q46 — ptsPDF Q47 Codling Moth, Temperature/Humidity Ecological Niche EcologyHard IBO·2022·Q47 — ptsPDF Q48 Sockeye Salmon, Life Stages and Chukchi Population Age Structure EcologyMedium IBO·2022·Q48 — ptsPDF Q49 Biological Nitrogen Fixation, Diazotrophs and Nitrogenase Mineral Nutrition & Nutrient UptakeEasy IBO·2022·Q49 — ptsPDF