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Question Bank

Every question across the whole archive, in one place. Search by keyword or filter by olympiad and topic to find practice on exactly what you’re working on.

867 questions across the archive, searchable and filterable by olympiad, year, and topic, and difficulty.

QuestionOlympiadYear / RoundSubjectsDifficulty
Q1. Poiseuille's Law and Blood Pressure Regulation IBO 2015: Theoretical A
Cardiovascular Physiology
Q2. Anion Effects on Hemoglobin Oxygen Affinity IBO 2015: Theoretical A
Respiratory Physiology
Q3. Visual Field Deficits from Central Visual Pathway Lesions IBO 2015: Theoretical A
Nervous System Physiology
Q4. Hippocampal Plasticity in London Taxi Drivers IBO 2015: Theoretical A
Nervous System Physiology
Q5. Kidney Filtration, Excretion and Oxygen Use in Three Individuals IBO 2015: Theoretical A
Comparative Osmoregulation & Excretion
Q6. Vascular Adaptations Preventing Leg Oedema in Giraffes IBO 2015: Theoretical A
Cardiovascular Physiology
Q7. Vocalization Frequency and Body Size in Whales IBO 2015: Theoretical A
Animal Communication
Q8. Anaerobic Lactate-to-Ethanol Metabolism in Goldfish IBO 2015: Theoretical A
Digestive & Metabolic Physiology
Q9. Metabolic Rate Scaling During Flounder Development IBO 2015: Theoretical A
Digestive & Metabolic Physiology
Q10. The Coagulation Cascade and Vitamin K IBO 2015: Theoretical A
Cardiovascular Physiology
Q11. Temperature, Lactic Acid and Salbutamol Effects on Muscle Fatigue IBO 2015: Theoretical A
Muscle Physiology
Q12. Stevioside and Soy Protein Effects on Diabetic Rats IBO 2015: Theoretical A
Endocrine System Physiology
Q13. Countercurrent Heat Exchange in Thermoregulation IBO 2015: Theoretical A
Comparative Thermoregulation
Q14. C3 and C4 Leaf Anatomy and Climate IBO 2015: Theoretical A
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q15. Chloroplast DNA Haplotypes in a Rare Japanese Orchid IBO 2015: Theoretical A
Genetic Drift, Gene Flow & Mutation
Q16. Nitrous Oxide Production by Bacteria in Zebra Mussels IBO 2015: Theoretical A
Ecology
Q17. An Adenosine Analogue as a Filovirus Therapeutic IBO 2015: Theoretical A
Nucleotide & Nucleic Acid Chemistry
Q18. The ABC Gene Model of Monocot Flower Development IBO 2015: Theoretical A
Flower Anatomy & Reproductive Structures
Q19. Electron Transport Between Oxic and Anoxic Marine Sediment Layers IBO 2015: Theoretical A
Ecology
Q20. Timing Gene Transfer During Bacterial Conjugation IBO 2015: Theoretical A
Linkage, Recombination & Genetic Mapping
Q21. Cholera Toxin Signaling and a CFTR Inhibitor Treatment IBO 2015: Theoretical A
Cell Signaling & CommunicationPlasma Membrane Structure & Transport
Q22. Adipose Tissue as a Host Response to Skin Infection IBO 2015: Theoretical A
Immune Physiology
Q23. Rhizobium Nodulation and Gene Structure in Lotus japonicus IBO 2015: Theoretical A
Transcription & RNA Processing
Q24. Competing Hypotheses for Darwin's Finch Diversification IBO 2015: Theoretical A
Coevolution & Species Interactions
Q25. Coevolutionary Arms Race Between Toxic Newts and Resistant Snakes IBO 2015: Theoretical A
Coevolution & Species Interactions
Q26. Indirect Effects of Introduced Arctic Foxes on Island Vegetation IBO 2015: Theoretical A
Ecology
Q27. Diet Differences Between Island and Mainland Chough Populations IBO 2015: Theoretical A
Ecology
Q28. Fruit Availability and Fish Diet Niche in Amazon Floodplains IBO 2015: Theoretical A
Ecology
Q29. Species Extinction on Islands Created by Reservoir Flooding IBO 2015: Theoretical A
Ecology
Q30. Orientation Cages and Migratory Direction in Indigo Buntings IBO 2015: Theoretical A
Orientation & Navigation
Q31. Wind Adaptation and Flightlessness in an Island Butterfly IBO 2015: Theoretical A
Natural Selection: Modes & Fitness
Q32. Stress Behaviour and Cortisol in Farmed Mink IBO 2015: Theoretical A
Mechanisms of BehaviorEndocrine System Physiology
Q33. ABO Blood Group Compatibility in Transfusion IBO 2015: Theoretical A
Human Circulatory System
Q34. Environmental DNA and Acoustic Detection of Harbour Porpoises IBO 2015: Theoretical A
Molecular Systematics
Q35. Multi-Locus Blood Typing to Resolve a Paternity Case IBO 2015: Theoretical A
Pedigree Analysis & Human Genetic Disorders
Q36. A Frameshift Mutation Causing Ficolin-3 Deficiency IBO 2015: Theoretical A
Translation & the Genetic Code
Q37. Restriction Fragment Analysis of a Growth Hormone Deletion IBO 2015: Theoretical A
Pedigree Analysis & Human Genetic Disorders
Q38. A Pedigree with Two X-Linked Disorders IBO 2015: Theoretical A
Sex Determination & Sex-Linked Inheritance
Q39. Sex-Linked Plumage Colour Inheritance in Chickens IBO 2015: Theoretical A
Sex Determination & Sex-Linked Inheritance
Q40. Hardy-Weinberg and the Evolution of Lactose Tolerance IBO 2015: Theoretical A
Population Genetics & Hardy-Weinberg Equilibrium
Q41. Complementation Analysis of the Arginine Biosynthesis Pathway IBO 2015: Theoretical A
Gene Interactions: Epistasis & Complementation Analysis
Q42. Carrier Probability in an Autosomal Recessive Pedigree IBO 2015: Theoretical A
Pedigree Analysis & Human Genetic Disorders
Q43. Temperature and Invasive Algae Effects on Eelgrass Growth IBO 2015: Theoretical A
Plant Stress Physiology & Defense
Q44. Vegetation Removal and Permafrost Dynamics in Siberian Tundra IBO 2015: Theoretical A
Ecology
Q45. Sexual Dimorphism and Floral Evolution in Palm and Saxifrage IBO 2015: Theoretical A
Flower Anatomy & Reproductive Structures
Q46. Trade-offs Between Clonal and Sexual Reproduction in Bamboo IBO 2015: Theoretical A
Ecology
Q47. Prey-Induced Enzyme Activity in the Carnivorous Sundew IBO 2015: Theoretical A
Mineral Nutrition & Nutrient Uptake
Q48. CO2 and Temperature Effects on C3 versus C4 Photosynthesis IBO 2015: Theoretical A
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q49. Heterostyly and Pollen Transfer Efficiency in Primrose IBO 2015: Theoretical A
Flower Anatomy & Reproductive StructuresPopulation Genetics & Hardy-Weinberg Equilibrium
Q1. Conus Snail Toxins and the Neuromuscular Junction IBO 2015: Theoretical B
Nervous System Physiology
Q2. Hemoglobin Oxygen Affinity in Two Amazonian Fish IBO 2015: Theoretical B
Respiratory Physiology
Q3. Training Effects on Lung Ventilation and Hyperventilation IBO 2015: Theoretical B
Respiratory Physiology
Q4. Gut Hormones and Insulin Secretion After Gastric Bypass IBO 2015: Theoretical B
Endocrine System Physiology
Q5. Hummingbird Physiology Across an Elevation Gradient IBO 2015: Theoretical B
Comparative Thermoregulation
Q6. Reading Cardiac Cycle Information from an ECG IBO 2015: Theoretical B
Cardiovascular Physiology
Q7. Testosterone, Pituitary Feedback, and Body Mass IBO 2015: Theoretical B
Endocrine System Physiology
Q8. Oxygen Uptake and Lactate During and After Exercise IBO 2015: Theoretical B
Muscle Physiology
Q9. Camel Fat Metabolism and Water Economy IBO 2015: Theoretical B
Comparative Thermoregulation
Q10. Altitude Adaptation in Deer Mouse Hemoglobin IBO 2015: Theoretical B
Respiratory Physiology
Q11. Glycemic Index and Metabolic Response During Exercise IBO 2015: Theoretical B
Muscle Physiology
Q12. Phylogeny and Biogeography of Horseshoe Crabs IBO 2015: Theoretical B
Phylogenetic Trees & Cladistics
Q13. Island Colonization History of Canary Islands Beetles IBO 2015: Theoretical B
Phylogenetic Trees & Cladistics
Q14. Coevolution of Breeding and Pollination Systems in Figs IBO 2015: Theoretical B
Coevolution & Species Interactions
Q15. The Pathogenic Life Cycle of Mycobacterium tuberculosis IBO 2015: Theoretical B
Immune Physiology
Q16. Restriction Enzyme Strategies for Cloning a Gene IBO 2015: Theoretical B
Recombinant DNA & Biotechnology Techniques
Q17. Mating-Type Switching in Budding Yeast IBO 2015: Theoretical B
Gene Regulation: Eukaryotic & Epigenetics
Q18. Screening for Statin Resistance Genes in Yeast IBO 2015: Theoretical B
Enzyme Kinetics & Regulation
Q19. Point Mutations, Frameshifts, and Codon Degeneracy IBO 2015: Theoretical B
Translation & the Genetic Code
Q20. Genome Size and Base Composition in Horse-Family Hybrids IBO 2015: Theoretical B
Nucleotide & Nucleic Acid Chemistry
Q21. A Bacterium-Nematode-Fungus Chemical Signaling Chain IBO 2015: Theoretical B
Ecology
Q22. Stem Cell and Islet Co-transplantation for Diabetes IBO 2015: Theoretical B
Endocrine System Physiology
Q23. Nuclear and Mitochondrial DNA Origin After Nuclear Transfer IBO 2015: Theoretical B
Recombinant DNA & Biotechnology Techniques
Q24. Testing the Janzen-Connell Hypothesis with Pesticide Exclusion IBO 2015: Theoretical B
Ecology
Q25. A Seabird-Mediated Nutrient Cascade on an Atoll IBO 2015: Theoretical B
Ecology
Q26. Mercury Bioaccumulation Across the Marine Food Chain IBO 2015: Theoretical B
Ecology
Q27. Large Herbivore Decline and Dung Beetle Fauna Since the Last Glacial IBO 2015: Theoretical B
Ecology
Q28. Bumblebee-Flower Mismatch Under Climate Warming IBO 2015: Theoretical B
Coevolution & Species Interactions
Q29. How a Burrowing Polychaete Alters Sediment Nitrogen Cycling IBO 2015: Theoretical B
Ecology
Q30. Odour Receptors and Neuron Identity in C. elegans IBO 2015: Theoretical B
Nervous System Physiology
Q31. Street Lighting and the Timing of Dawn Birdsong IBO 2015: Theoretical B
Biological Rhythms
Q32. Gametophytic Self-Incompatibility Genetics in Clover IBO 2015: Theoretical B
Population Genetics & Hardy-Weinberg Equilibrium
Q33. Genotype and Phenotype Frequencies at a Three-Allele Locus IBO 2015: Theoretical B
Population Genetics & Hardy-Weinberg Equilibrium
Q34. Genotype-Dependent Outcomes of a Plant-Oomycete Interaction IBO 2015: Theoretical B
Coevolution & Species Interactions
Q35. Hardy-Weinberg Expectations Across Generations of a Cross IBO 2015: Theoretical B
Population Genetics & Hardy-Weinberg Equilibrium
Q36. Four Ways to Draw the Same Phylogeny IBO 2015: Theoretical B
Phylogenetic Trees & Cladistics
Q37. Frog Phylogeny and Gondwanan Biogeography IBO 2015: Theoretical B
Phylogenetic Trees & Cladistics
Q38. Salinity and Genetic Structure Among Baltic Fish IBO 2015: Theoretical B
Genetic Drift, Gene Flow & Mutation
Q39. Coding vs Non-Coding Sequence Signatures in Cross-Species Alignments IBO 2015: Theoretical B
Molecular Evolution & Neutral Theory
Q40. Rate and Fidelity of DNA Replication in Fast-Growing E. coli IBO 2015: Theoretical B
DNA Structure & Replication
Q41. Backcrossing to Introgress a Disease-Resistance Allele IBO 2015: Theoretical B
Quantitative Genetics, Heritability & Inbreeding
Q42. Day-Night Oxygen and Ethanol Cycling in Eelgrass Roots IBO 2015: Theoretical B
Root Anatomy
Q43. CAM Photosynthesis and Carbon Limitation in an Aquatic Plant IBO 2015: Theoretical B
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q44. Pollen Donor Competition on the Stigma IBO 2015: Theoretical B
Flower Anatomy & Reproductive Structures
Q45. Light and Depth Effects on Photosynthesis in a CAM Aquatic Plant IBO 2015: Theoretical B
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q46. The Mechanical Function of Buttress Roots IBO 2015: Theoretical B
Root Anatomy
Q47. Nutrient Limitation of Baltic Phytoplankton Groups IBO 2015: Theoretical B
Ecology
Q48. Reproductive Success in a Deceptively Pollinated Orchid IBO 2015: Theoretical B
Coevolution & Species Interactions
Q49. Specialization and Phylogenetic Structure in a Bird-Plant Interaction Network IBO 2015: Theoretical B
Coevolution & Species Interactions
Q1. Wee1/Cdc25 Feedback Control of M-Cdk Activity IBO 2016: Theoretical A
Cell Signaling & Communication
Q2. Estimating Translation Rate from a TMV Protein Pulse-Chase Gel IBO 2016: Theoretical A
Translation & the Genetic Code
Q3. Ordering a Proline Biosynthesis Pathway by Cross-Feeding IBO 2016: Theoretical A
Gene Regulation: Prokaryotic
Q4. Uncouplers and Inhibitors of Oxidative Phosphorylation IBO 2016: Theoretical A
Bioenergetics & Central Metabolism Overview
Q5. Mapping Membrane-Protein Topology with Protease Protection IBO 2016: Theoretical A
Plasma Membrane Structure & Transport
Q6. Desaturase Identity and Ethanol Tolerance in Yeast IBO 2016: Theoretical A
Lipids & Membrane Biochemistry
Q7. Feedback Regulation of the PHB Synthesis Pathway IBO 2016: Theoretical A
Bioenergetics & Central Metabolism Overview
Q8. Identifying Amino Acids from Peptide Mass Data IBO 2016: Theoretical A
Amino Acids & Protein Chemistry Fundamentals
Q9. Screening Shrimp Gut Bacteria for Probiotic Potential Against Vibrio IBO 2016: Theoretical A
Immune Physiology
Q10. Timing Cell-Cycle Phases with a Thymidine Pulse-Chase IBO 2016: Theoretical A
Cell Cycle, Mitosis & Meiosis
Q11. Cell Wall Elasticity and the Components of Water Potential IBO 2016: Theoretical A
Water Transport & Transpiration
Q12. C3 vs C4 Photosynthetic Response to Low Temperature IBO 2016: Theoretical A
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q13. A dme Mutant and Nitrogen Fixation in Soybean Root Nodules IBO 2016: Theoretical A
Mineral Nutrition & Nutrient Uptake
Q14. Symplastic vs Apoplastic Phloem Loading of Sucrose IBO 2016: Theoretical A
Phloem Transport & Translocation
Q15. Structural Changes Along Rhizophore Orders in Rhizophora mangle IBO 2016: Theoretical A
Stem Anatomy
Q16. Arsenic Accumulation and Growth in Athyrium yokoscense IBO 2016: Theoretical A
Mineral Nutrition & Nutrient Uptake
Q17. ABA and Ethephon Effects on Sweet Cherry Ripening IBO 2016: Theoretical A
Plant Hormones
Q18. Reading a Pressure-Volume Loop of the Cardiac Cycle IBO 2016: Theoretical A
Cardiovascular Physiology
Q19. Cardiac Output and Oxygen Delivery During Exercise (Fick Principle) IBO 2016: Theoretical A
Cardiovascular Physiology
Q20. Four Congenital Heart Defects and Their Hemodynamic Consequences IBO 2016: Theoretical A
Cardiovascular Physiology
Q21. Ventilation Rate vs Tidal Volume During Graded Exercise IBO 2016: Theoretical A
Respiratory Physiology
Q22. Predicting Action Potential Changes from Altered Ion Conditions IBO 2016: Theoretical A
Nervous System Physiology
Q23. Phlorizin, SGLT2 Inhibition, and Diabetic Mouse Kidney Physiology IBO 2016: Theoretical A
Homeostasis & Osmoregulation
Q24. Hormonal Features of Polycystic Ovarian Syndrome IBO 2016: Theoretical A
Endocrine System Physiology
Q25. Ion Transport Across the Freshwater Fish Gill Epithelium IBO 2016: Theoretical A
Comparative Osmoregulation & Excretion
Q26. Water Loading and Renal Handling in Two Groups of Students IBO 2016: Theoretical A
Homeostasis & Osmoregulation
Q27. Thermal Metabolic Profiles of Five Animal Species IBO 2016: Theoretical A
Comparative Thermoregulation
Q28. BDNF, β-AR Signaling, and Brown Fat Thermogenesis IBO 2016: Theoretical A
Endocrine System Physiology
Q29. Muscle Fiber-Type Gene Expression Across Three Human Leg Muscles IBO 2016: Theoretical A
Muscle Physiology
Q30. Localizing an Insulin-Signaling Defect from Binding and Glucose-Clearance Tests IBO 2016: Theoretical A
Endocrine System Physiology
Q31. Mapping Bulbul Territory Size from Playback Response Data IBO 2016: Theoretical A
Aggression, Territoriality & Social Structure
Q32. Reciprocal Altruism in Blood-Sharing Vampire Bats IBO 2016: Theoretical A
Kin Selection, Altruism & Eusociality
Q33. Complementation and Dominance in lac Operon Merodiploids IBO 2016: Theoretical A
Gene Regulation: Prokaryotic
Q34. Assigning Anonymous DNA Samples to Three Families by STR Profiling IBO 2016: Theoretical A
Pedigree Analysis & Human Genetic Disorders
Q35. Classifying Crossover Events from Linear Tetrad Data IBO 2016: Theoretical A
Linkage, Recombination & Genetic Mapping
Q36. Broad- vs Narrow-Sense Heritability and a Bean Seed-Weight Calculation IBO 2016: Theoretical A
Quantitative Genetics, Heritability & Inbreeding
Q37. Long-Term Selection Response and Its Limits in Tribolium Body Size IBO 2016: Theoretical A
Quantitative Genetics, Heritability & Inbreeding
Q38. Inferring Chromosomal Rearrangements from Post-Fertilization Embryo Loss IBO 2016: Theoretical A
Chromosomal Variation: Number & Structure
Q39. Factors That Speed Up or Slow Down Speciation IBO 2016: Theoretical A
Speciation & Reproductive Isolation
Q40. Reconstructing Codon 38 of Tryptophan Synthetase from Revertant Analysis IBO 2016: Theoretical A
Translation & the Genetic Code
Q41. Applying Hardy-Weinberg Equilibrium to the ABO Blood Group System IBO 2016: Theoretical A
Population Genetics & Hardy-Weinberg Equilibrium
Q42. Positive vs Negative Frequency-Dependent Selection in Practice IBO 2016: Theoretical A
Natural Selection: Modes & Fitness
Q43. Non-Lethal Predation Effects on Dragonfly Larval Survival and Metamorphosis IBO 2016: Theoretical A
Ecology
Q44. Temperature-Dependent Competitive Outcomes Between Two Salmonid Fishes IBO 2016: Theoretical A
Ecology
Q45. Predator-Specific Effects on Guppy Color-Pattern Evolution IBO 2016: Theoretical A
Natural Selection: Modes & Fitness
Q46. Grazing Intensity, Root Competition, and Sex Ratio in Poa Grass IBO 2016: Theoretical A
Ecology
Q47. Gut Passage and Germination of Mimosa Seeds Ingested by Goats IBO 2016: Theoretical A
Coevolution & Species Interactions
Q48. Reading Relationships from a Five-Taxon Cladogram IBO 2016: Theoretical A
Phylogenetic Trees & Cladistics
Q49. Polyphyletic and Paraphyletic Groups in Modern Classification IBO 2016: Theoretical A
Classification Principles & Nomenclature
Q50. Pitfalls of Molecular Sequences as Phylogenetic Markers IBO 2016: Theoretical A
Molecular Systematics
Q51. Phage-Display Screen for Protein Kinase Inhibitors IBO 2016: Theoretical B
Recombinant DNA & Biotechnology Techniques
Q52. Telomere Shortening in Fission-Yeast Telomerase Mutants IBO 2016: Theoretical B
DNA Structure & Replication
Q53. Mitochondrial Membrane Potential in Hypoxia/Reoxygenation Injury IBO 2016: Theoretical B
Cardiovascular Physiology
Q54. Structure-Activity Relationships of Antifreeze Glycoproteins IBO 2016: Theoretical B
Carbohydrate Chemistry & Biology
Q55. Filming Rotary Catalysis in F1-ATPase IBO 2016: Theoretical B
Bioenergetics & Central Metabolism Overview
Q56. Microbial Succession During Cabbage Lactic Fermentation IBO 2016: Theoretical B
Bioenergetics & Central Metabolism Overview
Q57. Protein Adaptations of Halophilic Archaea to High Intracellular Salt IBO 2016: Theoretical B
Protein Structure, Folding & Function
Q58. Genome Segmentation and Subtype Diversity in Influenza A IBO 2016: Theoretical B
Molecular Evolution & Neutral Theory
Q59. Mapping p35 Phosphorylation Sites with a Phospho-Tag Gel IBO 2016: Theoretical B
Cell Signaling & Communication
Q60. pH-Dependent Membrane Diffusion of Aspirin and Arginine IBO 2016: Theoretical B
Plasma Membrane Structure & Transport
Q61. Cadmium's Effect on Maize Root Elongation and Endodermal Suberization IBO 2016: Theoretical B
Root Anatomy
Q62. Habitat-Linked Hydraulic Vulnerability in Ranunculus Species IBO 2016: Theoretical B
Water Transport & Transpiration
Q63. GPI-Anchoring Deficiency and Growth Phenotypes in an Arabidopsis atgpi8 Mutant IBO 2016: Theoretical B
Plasma Membrane Structure & Transport
Q64. Diurnal Light and CO2 Co-Limitation of Underwater Photosynthesis IBO 2016: Theoretical B
Light Reactions & Photophosphorylation
Q65. Nitric Oxide Feedback in Plant Nitrate Assimilation IBO 2016: Theoretical B
Mineral Nutrition & Nutrient Uptake
Q66. Comparing Lead Toxicity Thresholds for Growth and Photosynthesis in Two Microalgae IBO 2016: Theoretical B
Bioenergetics & Central Metabolism Overview
Q67. Gibberellin Signaling and Root/Shoot Allocation in Transgenic Poplar IBO 2016: Theoretical B
Plant Hormones
Q68. Hormonal Correlates of the Cucumber Super-Ovary Phenotype IBO 2016: Theoretical B
Plant Hormones
Q69. Localizing Drug Targets in the Parietal Cell Acid-Secretion Pathway IBO 2016: Theoretical B
Digestive & Metabolic Physiology
Q70. 4-1BB/4-1BBL Signaling in Atherosclerosis, Autoimmunity, and Graft Rejection IBO 2016: Theoretical B
Immune Physiology
Q71. Reading Cardiac Action Potential Phases from Ion Movements IBO 2016: Theoretical B
Cardiovascular Physiology
Q72. Identifying PTH, Calcium, and Phosphate Curves After PTH-Secretion Blockade IBO 2016: Theoretical B
Endocrine System Physiology
Q73. Regional Blood Flow Redistribution During Strenuous Exercise IBO 2016: Theoretical B
Cardiovascular Physiology
Q74. Compensatory Cardiovascular Responses to Acute Hemorrhage IBO 2016: Theoretical B
Cardiovascular Physiology
Q75. Distinguishing Obstructive and Restrictive Patterns on a Flow-Volume Loop IBO 2016: Theoretical B
Respiratory Physiology
Q76. Temporal and Spatial Summation at a Postsynaptic Neuron IBO 2016: Theoretical B
Nervous System Physiology
Q77. Tracing Endocrine Feedback Loops with Sensitivity-Altering Drugs IBO 2016: Theoretical B
Endocrine System Physiology
Q78. Cortisol and 2-AG Dynamics During Motion-Sickness-Inducing Flight IBO 2016: Theoretical B
Endocrine System Physiology
Q79. Physiological Adaptation to High-Altitude Hypoxia IBO 2016: Theoretical B
Respiratory Physiology
Q80. Species Differences in Oxygen Dissociation and the Bohr Effect IBO 2016: Theoretical B
Respiratory Physiology
Q81. Clutch-Size Manipulation and Optimal Brood Size in Magpies IBO 2016: Theoretical B
Foraging & Anti-Predator Behavior
Q82. Female Choice and Interspecific Hood-Burrow Sharing in Fiddler Crabs IBO 2016: Theoretical B
Mating Systems & Sexual Selection
Q83. Frequency-Dependent Predation and the Maintenance of Moth Wing-Pattern Polymorphism IBO 2016: Theoretical B
Foraging & Anti-Predator Behavior
Q84. Mapping Linked Genes from a Four-Gene Testcross IBO 2016: Theoretical B
Linkage, Recombination & Genetic Mapping
Q85. Complementation Analysis of Three White-Flowered Mutant Lines IBO 2016: Theoretical B
Gene Interactions: Epistasis & Complementation Analysis
Q86. Applying Mutation-Selection and Heterozygote-Advantage Models to a Recessive Lethal Allele IBO 2016: Theoretical B
Population Genetics & Hardy-Weinberg Equilibrium
Q87. Genetic Mechanisms Behind Inherited and Sporadic Cancers IBO 2016: Theoretical B
Gene Regulation: Eukaryotic & Epigenetics
Q88. Chromosome Size, Gene Density, and Embryonic Lethality in Mouse Trisomies IBO 2016: Theoretical B
Chromosomal Variation: Number & Structure
Q89. Functional Consequences of mRNA Circularization IBO 2016: Theoretical B
Translation & the Genetic Code
Q90. Reading Mode of Inheritance from Four Pedigrees IBO 2016: Theoretical B
Pedigree Analysis & Human Genetic Disorders
Q91. Using SNPs, Autosomal STRs, Y-STRs, and mtDNA to Reconstruct a Family IBO 2016: Theoretical B
Extranuclear & Non-Mendelian Inheritance
Q92. Deducing an X-Chromosome Deletion from an Unusual Drosophila Cross IBO 2016: Theoretical B
Chromosomal Variation: Number & Structure
Q93. Determining Insert Size and Orientation by Restriction Mapping IBO 2016: Theoretical B
Recombinant DNA & Biotechnology Techniques
Q94. How Many DBH Categories Are Needed to Accurately Age a Tree? IBO 2016: Theoretical B
Secondary Growth & Wood Anatomy
Q95. Slug, Earthworm, and Vegetation-Type Effects on Forest Seedling Survival IBO 2016: Theoretical B
Ecology
Q96. Plant Species Richness Effects on Biomass and Soil Carbon/Nitrogen Stocks IBO 2016: Theoretical B
Ecology
Q97. Grazer Identity, Diversity, and Nutrient Enrichment in Rock-Pool Food Webs IBO 2016: Theoretical B
Ecology
Q98. Modeling Stable Population Size in Gall Aphids IBO 2016: Theoretical B
Ecology
Q99. What Phylogenetic Trees Can and Cannot Reveal IBO 2016: Theoretical B
Phylogenetic Trees & Cladistics
Q100. Sequence Divergence, Substitution Counting, and Molecular Clock Assumptions IBO 2016: Theoretical B
Molecular Evolution & Neutral Theory
Q1. Choosing a Sequencing Technology for Rare-Disease Genomes IBO 2017: Theoretical A
Biomolecular Analytical Techniques
Q2. Contamination and Degradation in Ancient DNA IBO 2017: Theoretical A
Biomolecular Analytical TechniquesMolecular Systematics
Q3. Two Molecular Subtypes of DLBCL Lymphoma IBO 2017: Theoretical A
Biomolecular Analytical Techniques
Q4. Stochastic Noise in a Dual-Reporter Plasmid IBO 2017: Theoretical A
Gene Regulation: Prokaryotic
Q5. H2A.Z Occupancy and Temperature-Driven Flowering IBO 2017: Theoretical A
Gene Regulation: Eukaryotic & Epigenetics
Q6. Heritable Silencing of a Transgene by RNA IBO 2017: Theoretical A
Gene Regulation: Eukaryotic & Epigenetics
Q7. Designing a CRISPR Knockout of Gene X IBO 2017: Theoretical A
Recombinant DNA & Biotechnology Techniques
Q8. Coordinating Enzymes at the E. coli Replication Fork IBO 2017: Theoretical A
DNA Structure & Replication
Q9. Reading Adenovirus Transcription/Splicing from EM Images IBO 2017: Theoretical A
Transcription & RNA Processing
Q10. Timescales and Fragment Sizes Behind a DYSTROPHIN Diagnosis IBO 2017: Theoretical A
Pedigree Analysis & Human Genetic DisordersRecombinant DNA & Biotechnology Techniques
Q11. Recombination Mapping from a Three-Point Drosophila Cross IBO 2017: Theoretical A
Linkage, Recombination & Genetic Mapping
Q12. CwiM as a Zinc-Dependent Regulator of Mycobacterial Cell Elongation IBO 2017: Theoretical A
Protein Structure, Folding & Function
Q13. Pat and Cob Control Acetylation and Growth in Salmonella IBO 2017: Theoretical A
Enzyme Kinetics & Regulation
Q14. Seasonal Gene Expression in Cork Formation IBO 2017: Theoretical A
Secondary Growth & Wood AnatomyPlant Stress Physiology & Defense
Q15. Reversible Enzymes Shape the Cinchona Alkaloid Pathway IBO 2017: Theoretical A
Bioenergetics & Central Metabolism Overview
Q16. Cytokinin Receptor Loss and Day-Length Stress in Arabidopsis IBO 2017: Theoretical A
Biological RhythmsPlant Hormones
Q17. Phenolics from Oak Galls Protect Auxin from Oxidation IBO 2017: Theoretical A
Plant HormonesPlant Stress Physiology & Defense
Q18. Untangling GH and IGF1 Roles in Growth-Plate Elongation IBO 2017: Theoretical A
Endocrine System Physiology
Q19. Grafting Reveals Where RMS1 Signalling Originates IBO 2017: Theoretical A
Plant Hormones
Q20. Comm and Robo Set Midline-Crossing Behaviour in Drosophila Neurons IBO 2017: Theoretical A
Cell Signaling & Communication
Q21. Testing Zebrafish Stripes as a Turing Pattern IBO 2017: Theoretical A
Evolutionary Developmental Biology (Evo-Devo)
Q22. Mapping >12,000 Human Proteins Across Cell Organelles IBO 2017: Theoretical A
Endomembrane System & Protein Trafficking
Q23. Geometry and Gradients Set Calcium Flow at the Muscle Membrane IBO 2017: Theoretical A
Muscle PhysiologyCell Signaling & Communication
Q24. Directionality and Excitability of the Giant Worm Action Potential IBO 2017: Theoretical A
Nervous System Physiology
Q25. Summation and Inhibition Set the Threshold at Neuron 4 IBO 2017: Theoretical A
Nervous System Physiology
Q26. Receptor Occupancy and a Non-Competitive Inhibitor of Acetylcholine Signalling IBO 2017: Theoretical A
Cell Signaling & Communication
Q27. Arouser Links Egfr Signalling to Alcohol Sensitivity and Social Isolation IBO 2017: Theoretical A
Mechanisms of BehaviorCell Signaling & Communication
Q28. Optogenetically Implanting a False Fear Memory in Mice IBO 2017: Theoretical A
Development & Learning
Q29. Independent Assortment of Burrow Traits in Hybrid Mice IBO 2017: Theoretical A
Linkage, Recombination & Genetic MappingQuantitative Genetics, Heritability & Inbreeding
Q30. Radar-Tracked Foraging Reveals Bee Route Memory, Not Optimisation IBO 2017: Theoretical A
Orientation & NavigationForaging & Anti-Predator Behavior
Q31. Serial Reproduction and the Drift of Remembered Images IBO 2017: Theoretical A
Development & Learning
Q32. Locating the Blood- and Nerve-Dependent Control of the Pituitary IBO 2017: Theoretical A
Endocrine System Physiology
Q33. Parabiosis Reveals a Circulating Satiety Hormone in Obese Mice IBO 2017: Theoretical A
Endocrine System PhysiologyGene Interactions: Epistasis & Complementation Analysis
Q34. Contrasting N:P Limitation Across European Coastal Waters IBO 2017: Theoretical A
Ecology
Q35. Cross-Reactivity Limits an ELISA for Triazine Pesticides IBO 2017: Theoretical A
Biomolecular Analytical TechniquesImmune Physiology
Q36. Phylogenetic Age Predicts Extinction Risk in Madagascan Plants IBO 2017: Theoretical A
Phylogenetic Trees & CladisticsEcology
Q37. Windfarm Construction Disrupts Bird Populations More Than Operation IBO 2017: Theoretical A
Ecology
Q38. Myxomatosis, Introduced Parakeets, and a Native Falcon in Britain IBO 2017: Theoretical A
Ecology
Q39. Limpets and Urchins Have Unequal Effects on Seaweed Cover IBO 2017: Theoretical A
Ecology
Q40. Route Choice and Season Explain Cuckoo Population Trends IBO 2017: Theoretical A
Orientation & NavigationEcology
Q41. Mark-Recapture and Hybridisation Risk in Scottish Wildcats IBO 2017: Theoretical A
EcologySpeciation & Reproductive Isolation
Q42. Correlated rDNA Abundances Reveal Bacterial Niche Structure IBO 2017: Theoretical A
EcologyCoevolution & Species Interactions
Q43. A Global Haplotype Network Traces Human and Denisovan Ancestry IBO 2017: Theoretical A
Human Evolution & Hominid PhylogenyMolecular Systematics
Q44. From Hamilton's Rule to the Price Equation in Social Evolution IBO 2017: Theoretical A
Kin Selection, Altruism & EusocialityQuantitative Genetics, Heritability & Inbreeding
Q45. Artificial Selection Reveals Genetic Variation in Eyespot Traits IBO 2017: Theoretical A
Quantitative Genetics, Heritability & InbreedingNatural Selection: Modes & Fitness
Q46. A Selective Sweep in Cortex Explains Peppered Moth Melanism IBO 2017: Theoretical A
Natural Selection: Modes & FitnessMolecular Evolution & Neutral Theory
Q1. Enzyme-Limited Carbon Fixation in a Warming Amazon IBO 2017: Theoretical B
Calvin Cycle, Photorespiration & C4/CAM BiochemistryEcology
Q2. Ocean Acidification and Deep-Sea Chemosynthesis IBO 2017: Theoretical B
EcologyBioenergetics & Central Metabolism Overview
Q3. Reading Lung and Kidney Disease from Blood Gas Values IBO 2017: Theoretical B
Respiratory Physiology
Q4. Carbon Monoxide's Real Effect on Oxygen Transport IBO 2017: Theoretical B
Respiratory Physiology
Q5. CO2, Not O2, Drives Everyday Breathing Rate IBO 2017: Theoretical B
Respiratory Physiology
Q6. Comparing Gas Exchange Strategies Across Animal Groups IBO 2017: Theoretical B
Comparative Respiration & Circulation
Q7. Tidal Pressure Changes Drive Mangrove Root Gas Exchange IBO 2017: Theoretical B
Stomatal Physiology & Gas Exchange
Q8. Temperature and Metabolism Set Oxygen Levels in a Seagrass Meristem IBO 2017: Theoretical B
Stomatal Physiology & Gas Exchange
Q9. Counting Electrons Through the Oxygen-Evolving Complex IBO 2017: Theoretical B
Light Reactions & Photophosphorylation
Q10. Why the Heart Can't Suck Blood: The Frank-Starling Mechanism IBO 2017: Theoretical B
Cardiovascular Physiology
Q11. Diagnosing Heart Disease from Pressure-Volume Loops IBO 2017: Theoretical B
Cardiovascular Physiology
Q12. Osmolarity, Not Volume, Dominates Fast Kidney Responses IBO 2017: Theoretical B
Homeostasis & Osmoregulation
Q13. Glomerulus Size and Habitat Shape Kidney Concentrating Power IBO 2017: Theoretical B
Comparative Osmoregulation & Excretion
Q14. Using Inulin Clearance to Measure Kidney Filtration IBO 2017: Theoretical B
Homeostasis & Osmoregulation
Q15. Competition and Salt Tolerance Divide Two Marsh Plants IBO 2017: Theoretical B
Plant Stress Physiology & DefenseEcology
Q16. Antifreeze Proteins and Membrane Chemistry in Polar Fish IBO 2017: Theoretical B
Comparative ThermoregulationLipids & Membrane Biochemistry
Q17. Genome Streamlining Tracks Niche Specialisation in Marine Cyanobacteria IBO 2017: Theoretical B
Molecular Evolution & Neutral TheoryEcology
Q18. Surface-to-Volume Scaling Explains Animal Body Proportions IBO 2017: Theoretical B
Locomotion & Energetics
Q19. Fibre-Type Composition Explains a Human-Chimp Muscle Trade-off IBO 2017: Theoretical B
Muscle Physiology
Q20. A Revised Dinosaur Phylogeny Overturns Assumptions About Traits IBO 2017: Theoretical B
Phylogenetic Trees & Cladistics
Q21. Gut Anatomy Tracks Diet Across Apes, Dogs, and Pandas IBO 2017: Theoretical B
Digestive & Metabolic Physiology
Q22. Ancient DNA Reveals the Beaker People Replaced, Not Joined, Britain IBO 2017: Theoretical B
Human Evolution & Hominid PhylogenyPopulation Genetics & Hardy-Weinberg Equilibrium
Q23. Temperature-Dependent Sex Determination in Two Turtle Populations IBO 2017: Theoretical B
Reproductive PhysiologyEcology
Q24. Reading Cell Identity and Function from Testis Ultrastructure IBO 2017: Theoretical B
Reproductive Physiology
Q25. Do ABC Transporters Pump Floral Scent Out of Petal Cells? IBO 2017: Theoretical B
Plasma Membrane Structure & Transport
Q26. Homeotic Genes Define Flower and Body Segment Identity IBO 2017: Theoretical B
Flower Anatomy & Reproductive StructuresEvolutionary Developmental Biology (Evo-Devo)
Q27. Fruitless Isoforms Separate Appearance from Sexual Orientation IBO 2017: Theoretical B
Mechanisms of Behavior
Q28. Cytoplasmic Reprogramming and the Persistence of Cell Identity IBO 2017: Theoretical B
Gene Regulation: Eukaryotic & Epigenetics
Q29. Random Sorting of Chloroplasts in a Variegated Plant IBO 2017: Theoretical B
Extranuclear & Non-Mendelian Inheritance
Q30. Heteroplasmy Thresholds Behind Mitochondrial Replacement Therapy IBO 2017: Theoretical B
Mitochondria & Chloroplasts: Structure & Endosymbiotic OriginExtranuclear & Non-Mendelian Inheritance
Q31. Grafting Reveals Barriers to Gene and Genome Transfer Between Species IBO 2017: Theoretical B
Extranuclear & Non-Mendelian InheritanceSpeciation & Reproductive Isolation
Q32. Human Embryos Break the Established OCT4/GATA6 Rulebook IBO 2017: Theoretical B
Cell Signaling & CommunicationEvolutionary Developmental Biology (Evo-Devo)
Q33. Which Developmental Unit Was Selected to Make Each Brassica Crop? IBO 2017: Theoretical B
Plant Body Plans Across Major Lineages
Q34. p53's Tetramer Threshold Guards Against Cancer IBO 2017: Theoretical B
Cell Cycle, Mitosis & Meiosis
Q35. "Seed and Soil": Why Tumours Favour Specific Secondary Organs IBO 2017: Theoretical B
Cell Junctions, Extracellular Matrix & Cell DeathNatural Selection: Modes & Fitness
Q36. A Luciferase Reporter Measures Caspase Activity in Apoptosis IBO 2017: Theoretical B
Cell Junctions, Extracellular Matrix & Cell Death
Q37. Rerouting Flux Through an Engineered Krebs Cycle for Lysine IBO 2017: Theoretical B
Bioenergetics & Central Metabolism Overview
Q38. Diagnosing Electron Transport Chain Poisons from O2 Traces IBO 2017: Theoretical B
Bioenergetics & Central Metabolism Overview
Q39. Phosphocreatine and Glycolysis Power the 100m Sprint IBO 2017: Theoretical B
Locomotion & EnergeticsBioenergetics & Central Metabolism Overview
Q40. Mendelian Randomisation Separates Correlation from Causation IBO 2017: Theoretical B
Population Genetics & Hardy-Weinberg Equilibrium
Q41. Antibody Evolution Traces the Red Queen Dynamic in Untreated HIV IBO 2017: Theoretical B
Molecular Evolution & Neutral TheoryImmune Physiology
Q42. Extracellular vs Intracellular Resistance Enzymes Shape Selection Pressure IBO 2017: Theoretical B
Natural Selection: Modes & Fitness
Q43. Self-Templating Misfolding Drives Prion Disease Dynamics IBO 2017: Theoretical B
Protein Structure, Folding & Function
Q44. Comparing Two Active-Site Inhibitors for a Tuberculosis Target IBO 2017: Theoretical B
Enzyme Kinetics & Regulation
Q45. Cross-Immunity and Persistence Explain Smallpox's Eradication over Cholera's IBO 2017: Theoretical B
Immune Physiology
Q46. Tracing a De Novo Haemophilia Mutation Through European Royalty IBO 2017: Theoretical B
Pedigree Analysis & Human Genetic DisordersSex Determination & Sex-Linked Inheritance
Q1. Neurospora Pathway Reconstruction IBO 2018: Theoretical 1
Gene Interactions: Epistasis & Complementation Analysis
Q2. DNA Barcoding in Persian Gulf Fish IBO 2018: Theoretical 1
Molecular Systematics
Q3. K2P Genetic Divergence Across Regions IBO 2018: Theoretical 1
Molecular Systematics
Q4. Pulse-Chase RNA Processing IBO 2018: Theoretical 1
Transcription & RNA Processing
Q5. Fluorescence Quenching of Tryptophan Residues IBO 2018: Theoretical 1
Protein Structure, Folding & Function
Q6. pHLIP-Mediated AntimiR Delivery to Tumours IBO 2018: Theoretical 1
Cell Signaling & Communication
Q7. Primary vs Secondary Response Genes IBO 2018: Theoretical 1
Gene Regulation: Eukaryotic & Epigenetics
Q8. Mitochondrial Uncoupling Drugs IBO 2018: Theoretical 1
Bioenergetics & Central Metabolism Overview
Q9. SalI/XhoI Restriction Cloning Analysis IBO 2018: Theoretical 1
Recombinant DNA & Biotechnology Techniques
Q10. Yeast Mating and Polygenic Complementation IBO 2018: Theoretical 1
Gene Interactions: Epistasis & Complementation Analysis
Q11. Alpha- vs Beta-Thalassemia and AHSP IBO 2018: Theoretical 1
Protein Structure, Folding & FunctionPedigree Analysis & Human Genetic Disorders
Q12. G6PD Deficiency and the Pentose Phosphate Pathway IBO 2018: Theoretical 1
Bioenergetics & Central Metabolism Overview
Q13. Beta-Clamp Processivity in DNA Polymerase III IBO 2018: Theoretical 1
DNA Structure & Replication
Q14. Two-Step Enzymatic Release of Para-nitrophenol IBO 2018: Theoretical 1
Enzyme Kinetics & Regulation
Q15. Amino Acid Carbon Labelling Through the Krebs Cycle IBO 2018: Theoretical 1
Bioenergetics & Central Metabolism Overview
Q16. Spinal Cord Injury and Sensory Pathways IBO 2018: Theoretical 1
Nervous System Physiology
Q17. Cardiac Cycle and Amygdala Fear Response IBO 2018: Theoretical 1
Nervous System PhysiologyCardiovascular Physiology
Q18. Light Refraction in the Four-Eyed Fish Anableps IBO 2018: Theoretical 1
Fish & Amphibian Anatomy
Q19. Thyroid Function Tests: TSH, T4, and T3RU IBO 2018: Theoretical 1
Endocrine System Physiology
Q20. Osmolality and Sperm Motility Initiation IBO 2018: Theoretical 1
Comparative Osmoregulation & ExcretionReproductive Physiology
Q21. EBV Screening Test Sensitivity and Specificity IBO 2018: Theoretical 1
Immune Physiology
Q22. Frog Embryo Sagittal and Cross Sections IBO 2018: Theoretical 1
Evolutionary Developmental Biology (Evo-Devo)
Q23. Specification vs Determination in Heterotopic Grafts IBO 2018: Theoretical 1
Evolutionary Developmental Biology (Evo-Devo)
Q24. Phylogenetic Position of Symsagittifera IBO 2018: Theoretical 1
Phylogenetic Trees & Cladistics
Q25. Phylogenetic Position of Dicyemids IBO 2018: Theoretical 1
Phylogenetic Trees & Cladistics
Q26. Comparative Flight Muscle Anatomy of Birds and Bats IBO 2018: Theoretical 1
Locomotion & EnergeticsMammalian Comparative Anatomy
Q27. Anthocyanin Pigments in Water Lily Flower Colour IBO 2018: Theoretical 1
Carbohydrate Chemistry & Biology
Q28. Boron-Sugar Complexes and Pollen Tube Growth IBO 2018: Theoretical 1
Mineral Nutrition & Nutrient Uptake
Q29. Rhizobial Nitrogen Fixation Symbiosis IBO 2018: Theoretical 1
Mineral Nutrition & Nutrient Uptake
Q30. Light Colour Effects on Photosynthesis in Arabidopsis IBO 2018: Theoretical 1
Light Reactions & Photophosphorylation
Q31. Adaptations of Submerged Aquatic Plants IBO 2018: Theoretical 1
Water Transport & Transpiration
Q32. Speciation and Extinction Rates Across Plant Habits IBO 2018: Theoretical 1
Macroevolutionary Patterns & Mass Extinctions
Q33. Evolution of Annual vs Perennial Life-History in Nemesia IBO 2018: Theoretical 1
Macroevolutionary Patterns & Mass Extinctions
Q34. Polyploidy and Alpine Habitat in Veronica IBO 2018: Theoretical 1
Macroevolutionary Patterns & Mass Extinctions
Q35. Kleptoplasty in Sacoglossan Sea Slugs IBO 2018: Theoretical 1
Mitochondria & Chloroplasts: Structure & Endosymbiotic Origin
Q36. Comparative Anatomy of a Leaf's Medial and Lateral Regions IBO 2018: Theoretical 1
Leaf Anatomy
Q37. Trophy Hunting and Bighorn Sheep Horn Size IBO 2018: Theoretical 1
Natural Selection: Modes & Fitness
Q38. Haldane's Rule in Mosquitoes IBO 2018: Theoretical 1
Speciation & Reproductive Isolation
Q39. Synonymous vs Non-Synonymous Variation in Humans IBO 2018: Theoretical 1
Molecular Evolution & Neutral Theory
Q40. Hypotheses for the Evolution of Sex IBO 2018: Theoretical 1
Genetic Drift, Gene Flow & Mutation
Q41. Gut Microbiota Across the Colorectal Cancer Progression IBO 2018: Theoretical 1
Ecology
Q42. Ecological Pyramids of Energy and Biomass IBO 2018: Theoretical 1
Ecology
Q43. Competitive Exclusion and Pitcher Plant Coexistence IBO 2018: Theoretical 1
Coevolution & Species Interactions
Q44. Regional vs Local Drivers of Species Diversity IBO 2018: Theoretical 1
Ecology
Q45. Risk-Taking and Social Dynamics in Adelie Penguins IBO 2018: Theoretical 1
Foraging & Anti-Predator Behavior
Q46. Conditional Cooperation and the Evolution of Deception IBO 2018: Theoretical 1
Kin Selection, Altruism & Eusociality
Q47. Williams' Evolutionary Theory of Senescence IBO 2018: Theoretical 1
Natural Selection: Modes & Fitness
Q1. Human SNP Haplotype Blocks IBO 2018: Theoretical 2
Population Genetics & Hardy-Weinberg Equilibrium
Q2. Berk-Sharp Mapping of Exon-Intron Structure IBO 2018: Theoretical 2
DNA Structure & Replication
Q3. Temporal Order of Intron Removal by Northern Blotting IBO 2018: Theoretical 2
Transcription & RNA Processing
Q4. Gasdermin D and Pyroptosis IBO 2018: Theoretical 2
Cell Junctions, Extracellular Matrix & Cell Death
Q5. Detecting Aneuploidy by PCR Fragment Analysis IBO 2018: Theoretical 2
Chromosomal Variation: Number & Structure
Q6. PTEN Knockdown and Neutrophil Differentiation IBO 2018: Theoretical 2
Cell Cycle, Mitosis & Meiosis
Q7. Hardy-Weinberg Analysis of the MN Blood Group IBO 2018: Theoretical 2
Population Genetics & Hardy-Weinberg Equilibrium
Q8. Dominant-Negative Effects in Receptor Tyrosine Kinase Mutants IBO 2018: Theoretical 2
Cell Signaling & Communication
Q9. Nuclear Import of the ErbB-2 Receptor IBO 2018: Theoretical 2
Endomembrane System & Protein Trafficking
Q10. Yeast Secretion Trap Screen for Phytopathogen Secretomes IBO 2018: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Q11. Thiamine Pyrophosphate Enzyme Kinetics in Disease IBO 2018: Theoretical 2
Enzyme Kinetics & Regulation
Q12. A FRET-Based Quantum Dot Maltose Biosensor IBO 2018: Theoretical 2
Biomolecular Analytical Techniques
Q13. GSK3 and Beta-Adrenergic Control of Thermogenic Genes IBO 2018: Theoretical 2
Cell Signaling & Communication
Q14. 2D Gel Analysis of Plasmodium Peroxiredoxin IBO 2018: Theoretical 2
Biomolecular Analytical Techniques
Q15. Enzyme Rate, Inhibition, and Allosteric Kinetics IBO 2018: Theoretical 2
Enzyme Kinetics & Regulation
Q16. Pedigree Analysis of Two Rare Traits IBO 2018: Theoretical 2
Pedigree Analysis & Human Genetic Disorders
Q17. Lateral Inhibition Between Sensory Pathways IBO 2018: Theoretical 2
Nervous System Physiology
Q18. Patch Clamp Analysis of a Cation Channel IBO 2018: Theoretical 2
Plasma Membrane Structure & Transport
Q19. Respiratory Phase and Memory Performance IBO 2018: Theoretical 2
Nervous System Physiology
Q20. MRI Weighting and Comparative Organ Anatomy IBO 2018: Theoretical 2
Digestive & Metabolic Physiology
Q21. Hormonal Control of the Menstrual Cycle IBO 2018: Theoretical 2
Reproductive Physiology
Q22. Direct and Indirect Coombs Tests IBO 2018: Theoretical 2
Immune Physiology
Q23. Ion Permeability and a Simple Reflex Circuit IBO 2018: Theoretical 2
Nervous System Physiology
Q24. HOX Genes, Retinoic Acid, and Neural Tube Patterning IBO 2018: Theoretical 2
Gene Regulation: Eukaryotic & Epigenetics
Q25. Maternal-Effect Inheritance of Snail Shell Coiling IBO 2018: Theoretical 2
Extranuclear & Non-Mendelian Inheritance
Q26. Classifying the Novel Taxon Dendrogramma IBO 2018: Theoretical 2
Phylogenetic Trees & Cladistics
Q27. Reciprocal Intraguild Predation Between Juveniles and Adults IBO 2018: Theoretical 2
Coevolution & Species Interactions
Q28. Tunicate Body Plan and Chordate Affinities IBO 2018: Theoretical 2
Cell Theory, Prokaryotes & Eukaryotes
Q29. Diagnostic Traits of Four Animal Phyla IBO 2018: Theoretical 2
Classification Principles & Nomenclature
Q30. Circulatory and Filter-Feeding Anatomy of Amphioxus IBO 2018: Theoretical 2
Fish & Amphibian Anatomy
Q31. Effect of Body Temperature on Canine ECG Intervals IBO 2018: Theoretical 2
Cardiovascular Physiology
Q32. Water-Absorbing Trichomes in Tank Bromeliads IBO 2018: Theoretical 2
Water Transport & Transpiration
Q33. Biphasic Kinetics of Potassium Uptake by Trichomes IBO 2018: Theoretical 2
Mineral Nutrition & Nutrient Uptake
Q34. Chloride-Induced Trichome Induction and Ion Exclusion IBO 2018: Theoretical 2
Mineral Nutrition & Nutrient Uptake
Q35. Identifying Unknown Plants from Vascular Tissue Traits IBO 2018: Theoretical 2
Xylem, Phloem & Vascular Tissue
Q36. Cladistic Analysis of the Plant Genus X IBO 2018: Theoretical 2
Phylogenetic Trees & Cladistics
Q37. Interpreting Floral Diagrams IBO 2018: Theoretical 2
Flower Anatomy & Reproductive Structures
Q38. Bacterial Phyllody and the ABCE Model IBO 2018: Theoretical 2
Gene Regulation: Eukaryotic & Epigenetics
Q39. The Leaf Economics Spectrum Across Vascular Plants IBO 2018: Theoretical 2
Leaf Anatomy
Q40. Tracing Gene X Through Enucleate Sieve-Tube Elements IBO 2018: Theoretical 2
Xylem, Phloem & Vascular Tissue
Q41. Runaway versus Chase-Away Sexual Selection IBO 2018: Theoretical 2
Natural Selection: Modes & Fitness
Q42. Adaptations, Spandrels, and Developmental Constraints IBO 2018: Theoretical 2
Evolutionary Developmental Biology (Evo-Devo)
Q43. The Godfrey-Smith Darwinian Space IBO 2018: Theoretical 2
Natural Selection: Modes & Fitness
Q44. Haldane's Estimate of the Human Mutation Rate IBO 2018: Theoretical 2
Genetic Drift, Gene Flow & Mutation
Q45. Phylogeography of the Indo-European Language Family IBO 2018: Theoretical 2
Molecular Systematics
Q46. Estimating Carrying Capacity from Population Growth Rate IBO 2018: Theoretical 2
Ecology
Q47. The Rise-and-Fall Pattern of Taxon Persistence in the Fossil Record IBO 2018: Theoretical 2
Macroevolutionary Patterns & Mass Extinctions
Q48. Thermoregulation and the Thermoneutral Zone IBO 2018: Theoretical 2
Comparative Thermoregulation
Q49. Transmission and Recovery Parameters in the SIR Model IBO 2018: Theoretical 2
Ecology
Q50. Repeatability of Personality Traits Across Spider Species IBO 2018: Theoretical 2
Mechanisms of Behavior
Q51. Contrasting Parasitic Strategies: Sam and Jack IBO 2018: Theoretical 2
Coevolution & Species Interactions
Q1. C. elegans Apoptosis Gene Network IBO 2019: Theoretical A
Cell Junctions, Extracellular Matrix & Cell Death
Q2. CLK Mutation and Circadian PER Oscillations IBO 2019: Theoretical A
Biological Rhythms
Q3. GPCR Signalling and a Toxin Acting on the Gs Cycle IBO 2019: Theoretical A
Cell Signaling & Communication
Q4. CDK Knockout and Liver Regeneration IBO 2019: Theoretical A
Cell Cycle, Mitosis & Meiosis
Q5. UCP Family and Non-Shivering Thermogenesis IBO 2019: Theoretical A
Comparative Thermoregulation
Q6. A Two-Polypeptide Gene with an Intron IBO 2019: Theoretical A
DNA Structure & Replication
Q7. Thermus szegediensis, Nutrition and Complementation IBO 2019: Theoretical A
Cell Theory, Prokaryotes & Eukaryotes
Q8. Beadle & Tatum, One Gene, One Enzyme IBO 2019: Theoretical A
Mendel's Laws & Probability in Genetics
Q9. Bulb1/Bulb2 and the UV-B Response in Arabidopsis IBO 2019: Theoretical A
Photoperiodism, Vernalization & Flowering
Q10. Pressure and Volume Changes During Breathing IBO 2019: Theoretical A
Respiratory Physiology
Q11. Acid-Base Balance, Reading a Blood Gas Map IBO 2019: Theoretical A
Homeostasis & Osmoregulation
Q12. Antibiotic Pharmacokinetics in a Cow IBO 2019: Theoretical A
Digestive & Metabolic Physiology
Q13. Renal Handling of Glucose IBO 2019: Theoretical A
Human Excretory System
Q14. Liver, Gallbladder, and Kidney Vessels IBO 2019: Theoretical A
Human Excretory System
Q15. Classifying Hypersensitivity Reactions IBO 2019: Theoretical A
Immune Physiology
Q16. Cochlear Frequency Coding and Sound Pressure IBO 2019: Theoretical A
Human Sensory Organs
Q17. Feeding Time and the Central vs. Peripheral Circadian Clock IBO 2019: Theoretical A
Biological Rhythms
Q18. The Thyroid Axis in Five Clinical Scenarios IBO 2019: Theoretical A
Endocrine System Physiology
Q19. Thyroid Hormone, Oxidative Stress, and the Heart IBO 2019: Theoretical A
Endocrine System Physiology
Q20. GNC/GLK Transcription Factors and Chloroplast Development IBO 2019: Theoretical A
Gene Regulation: Eukaryotic & Epigenetics
Q21. Drought Effects on Olive Leaf Anatomy IBO 2019: Theoretical A
Plant Stress Physiology & Defense
Q22. What Limits the Height of the Tallest Trees? IBO 2019: Theoretical A
Water Transport & Transpiration
Q23. Statoliths and Root Geotropism in Microgravity IBO 2019: Theoretical A
Tropisms & Nastic Movements
Q24. Nitric Oxide and Guard Cell K+ Currents IBO 2019: Theoretical A
Stomatal Physiology & Gas Exchange
Q25. The Luria-Delbrück Replica Plating Experiment IBO 2019: Theoretical A
Genetic Drift, Gene Flow & Mutation
Q26. Inheritance of Sterility in a Pedigree IBO 2019: Theoretical A
Pedigree Analysis & Human Genetic Disorders
Q27. Baldness, Rh Factor, and Genetic Counselling IBO 2019: Theoretical A
Linkage, Recombination & Genetic Mapping
Q28. How Long Until a Random Sequence Repeats in the Genome? IBO 2019: Theoretical A
Nucleotide & Nucleic Acid Chemistry
Q29. Reverse-Engineering a Peptide-Shortening Mutation IBO 2019: Theoretical A
Translation & the Genetic Code
Q30. An X-Linked, Epigenetically-Acting Eye-Colour Gene IBO 2019: Theoretical A
Mendel's Laws & Probability in Genetics
Q31. Smallmouth Bass Removal and Population Structure IBO 2019: Theoretical A
Ecology
Q32. The SIR Model of Parasite Population Dynamics IBO 2019: Theoretical A
Ecology
Q33. Tracing Indirect Effects Through a Food Web IBO 2019: Theoretical A
Ecology
Q34. Assembling a Bird Phylogenetic Tree from Fragments IBO 2019: Theoretical A
Phylogenetic Trees & Cladistics
Q35. A New Gall Wasp Genus, Molecular Systematics IBO 2019: Theoretical A
Molecular Systematics
Q36. Reconciling Two Independent Legume Phylogenies IBO 2019: Theoretical A
Phylogenetic Trees & Cladistics
Q37. Why Bats Collide With Smooth Surfaces IBO 2019: Theoretical A
Animal Communication
Q38. Attractant vs. Repellent Pheromones in Pharaoh Ants IBO 2019: Theoretical A
Animal Communication
Q1. Stereochemistry of Citrate and Isocitrate in the Aconitase Reaction IBO 2020: Theoretical 1
Bioenergetics & Central Metabolism Overview
Q2. Respiratory Control in Isolated Mitochondria: ADP, DNP and DCCD IBO 2020: Theoretical 1
Bioenergetics & Central Metabolism Overview
Q3. Carbon Isotope Fractionation in C3 versus C4 Photosynthesis IBO 2020: Theoretical 1
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q4. Sedimentation Coefficient and Centrifugation Physics IBO 2020: Theoretical 1
Biomolecular Analytical Techniques
Q5. ATP-Dependent Na+ Efflux in the Squid Giant Axon IBO 2020: Theoretical 1
Nervous System PhysiologyPlasma Membrane Structure & Transport
Q6. Nernst Potentials and Ion Transport Direction in Root Epidermal Cells IBO 2020: Theoretical 1
Mineral Nutrition & Nutrient UptakePlasma Membrane Structure & Transport
Q7. Glucosinolate Distribution and Herbivore Choice in Arabidopsis Leaves IBO 2020: Theoretical 1
Plant Stress Physiology & Defense
Q8. CAM-like Nocturnal Carbon Fixation in the Amphibious Plant Isoetes howelli IBO 2020: Theoretical 1
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q9. Start-Codon Selection Mechanisms in Prokaryotic versus Eukaryotic Translation IBO 2020: Theoretical 1
Translation & the Genetic Code
Q10. Cytosine Deamination and Why Uracil Is Excluded from DNA IBO 2020: Theoretical 1
Nucleotide & Nucleic Acid ChemistryDNA Repair & Recombination
Q11. Pedigree Analysis of Three Heritable Traits: Alfa, Baker and Charlie IBO 2020: Theoretical 1
Pedigree Analysis & Human Genetic Disorders
Q12. Regulation of the rut Operon by the RutR Repressor and Uracil IBO 2020: Theoretical 1
Gene Regulation: Prokaryotic
Q13. Bacterial Transcription Factors Coordinating Metabolic and Lifestyle Genes IBO 2020: Theoretical 1
Gene Regulation: Prokaryotic
Q14. Matching Molecular Biology Techniques to Research Questions IBO 2020: Theoretical 1
Recombinant DNA & Biotechnology TechniquesBiomolecular Analytical Techniques
Q15. Gibberellin and Abscisic Acid Control of Seed Germination IBO 2020: Theoretical 1
Plant HormonesSeed Germination & Dormancy Physiology
Q16. Designing Cloning Primers with Restriction Sites for Vector A IBO 2020: Theoretical 1
Recombinant DNA & Biotechnology Techniques
Q17. Predicting Reading-Frame Effects of CRISPR-Cas9 Indels IBO 2020: Theoretical 1
Recombinant DNA & Biotechnology Techniques
Q18. Transcriptional Attenuation of the E. coli trp Operon IBO 2020: Theoretical 1
Gene Regulation: Prokaryotic
Q19. Tissue Distribution of the Glucagon Receptor and Metabolic Roles IBO 2020: Theoretical 1
Endocrine System Physiology
Q20. Matching Muscle Energy Systems to Exercise Duration and Intensity IBO 2020: Theoretical 1
Muscle PhysiologyLocomotion & Energetics
Q21. Huntingtin, Glycolytic ATP and Fast Axonal Transport IBO 2020: Theoretical 1
Cytoskeleton & Motor ProteinsHuman Nervous System
Q22. Nephron Structure and Urine Concentrating Ability Across Habitats IBO 2020: Theoretical 1
Human Excretory SystemComparative Osmoregulation & Excretion
Q23. GABA-Induced Chloride Currents and Depolarization in a Hypothalamic Neuron IBO 2020: Theoretical 1
Nervous System PhysiologyPlasma Membrane Structure & Transport
Q24. Nuclear-to-Cytoplasmic Ratio and the Midblastula Transition in Xenopus IBO 2020: Theoretical 1
Cell Cycle, Mitosis & Meiosis
Q25. beta-catenin and GSK3beta in Xenopus Dorsal Organizer Formation IBO 2020: Theoretical 1
Cell Signaling & Communication
Q26. Thermoregulatory Strategies of Endotherms and Ectotherms IBO 2020: Theoretical 1
Comparative Thermoregulation
Q27. Finding the Minimal Reprogramming Gene Set for Fibroblasts IBO 2020: Theoretical 1
Gene Regulation: Eukaryotic & Epigenetics
Q28. Southern Blot Evidence for Immunoglobulin Light-Chain Gene Rearrangement IBO 2020: Theoretical 1
Recombinant DNA & Biotechnology TechniquesGene Regulation: Eukaryotic & Epigenetics
Q29. Stomatal Aperture Responses to Humidity in Air versus Helox IBO 2020: Theoretical 1
Stomatal Physiology & Gas Exchange
Q30. Systemin and Jasmonate Signaling in the Tomato Wound Response IBO 2020: Theoretical 1
Plant Stress Physiology & DefenseCell Signaling & Communication
Q31. Grafting Analysis of Strigolactone Biosynthesis and Perception in MAX Mutants IBO 2020: Theoretical 1
Plant Hormones
Q32. Zinc and Iron Interactions in Arabidopsis Micronutrient Toxicity IBO 2020: Theoretical 1
Mineral Nutrition & Nutrient Uptake
Q33. A CYCLOIDEA-like Gene Controlling Floral Symmetry in Sunflower IBO 2020: Theoretical 1
Flower Anatomy & Reproductive StructuresEvolutionary Developmental Biology (Evo-Devo)
Q34. Resource Sharing Between Stolon-Connected Ramets of Fragaria chiloensis IBO 2020: Theoretical 1
Phloem Transport & Translocation
Q35. Distinguishing Osmotic and Ionic Ca2+ Signaling Mutants in Salt Stress IBO 2020: Theoretical 1
Plant Stress Physiology & DefenseCell Signaling & Communication
Q36. Hardy-Weinberg, Genetic Drift and Fixation Probability in a Body-Color Locus IBO 2020: Theoretical 1
Population Genetics & Hardy-Weinberg Equilibrium
Q37. Gene Duplication and Selection in Primate ECP/EDN Ribonuclease Genes IBO 2020: Theoretical 1
Molecular Evolution & Neutral Theory
Q38. Parsimony Reconstruction of Opsin Gene Evolution in Human and Zebrafish IBO 2020: Theoretical 1
Molecular Evolution & Neutral Theory
Q39. MC1R Alleles and Coat-Color Adaptation in Peromyscus polionotus IBO 2020: Theoretical 1
Natural Selection: Modes & FitnessPopulation Genetics & Hardy-Weinberg Equilibrium
Q40. Sensory Drive Speciation in Lake Victoria Cichlids IBO 2020: Theoretical 1
Speciation & Reproductive Isolation
Q41. Methodological Pitfalls in Molecular Phylogenetics IBO 2020: Theoretical 1
Molecular Systematics
Q42. Reading a Cetacean Phylogeny for Lifestyle and Trait Evolution IBO 2020: Theoretical 1
Evidence for Evolution
Q43. Hox Gene Collinearity and Ubx Function Across Insect Lineages IBO 2020: Theoretical 1
Evolutionary Developmental Biology (Evo-Devo)
Q44. Pitx1 Expression and Convergent Pelvic Reduction in Stickleback IBO 2020: Theoretical 1
Evolutionary Developmental Biology (Evo-Devo)
Q45. Density-Dependent Growth Curves and Extinction Risk in Two Life-History Types IBO 2020: Theoretical 1
Ecology
Q46. Cost-Benefit Optimization of Animal Territory Size IBO 2020: Theoretical 1
Aggression, Territoriality & Social Structure
Q47. Day versus Night Pollinator Contributions to Goldenrod Seed Set IBO 2020: Theoretical 1
Coevolution & Species Interactions
Q48. Tracking Insecticide Resistance Allele Frequency Over Time in Mosquitoes IBO 2020: Theoretical 1
Natural Selection: Modes & Fitness
Q49. Species Dominance-Rank Curves and Community Change Over 50 Years IBO 2020: Theoretical 1
Ecology
Q50. Species Richness and Aboveground Biomass in Experimental Grassland Plots IBO 2020: Theoretical 1
Ecology
Q1. Glycogen and Amylopectin Degradation by Phosphorylase and Debranching Enzyme IBO 2020: Theoretical 2
Carbohydrate Chemistry & Biology
Q2. Classifying Endo-type and Exo-type Hydrolases by Biological Role IBO 2020: Theoretical 2
Enzyme Kinetics & Regulation
Q3. Ethanol as a Competitive Inhibitor of Alcohol Dehydrogenase Acting on Methanol IBO 2020: Theoretical 2
Enzyme Kinetics & Regulation
Q4. Predicting Sedimentation and Flotation Behavior in Three Centrifugation Setups IBO 2020: Theoretical 2
Biomolecular Analytical Techniques
Q5. Molecular Crowding of Hemoglobin and Ion Diffusion in Red Blood Cells IBO 2020: Theoretical 2
Plasma Membrane Structure & TransportHuman Circulatory System
Q6. Identifying Cytoskeleton Types from Function and Morphology IBO 2020: Theoretical 2
Cytoskeleton & Motor Proteins
Q7. Estimating Vmax and KM for GLUT1 Glucose Transport Kinetics IBO 2020: Theoretical 2
Enzyme Kinetics & RegulationPlasma Membrane Structure & Transport
Q8. Which Kinetic and Environmental Data Explain Rubisco's Carboxylase/Oxygenase Balance IBO 2020: Theoretical 2
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q9. Identifying the Ohsumi Yeast Autophagy Mutant and Autophagic Body Contents IBO 2020: Theoretical 2
Endomembrane System & Protein Trafficking
Q10. Matching Plant Cell Growth Types to Cellulose Microfibril and Microtubule Orientation IBO 2020: Theoretical 2
Cytoskeleton & Motor Proteins
Q11. Calculating Cell Cycle Length and Initial Ratio from Growth Curves IBO 2020: Theoretical 2
Cell Cycle, Mitosis & Meiosis
Q12. Determining Metabolic Pathway and ATP Yield from Gas Exchange in Yeast IBO 2020: Theoretical 2
Bioenergetics & Central Metabolism Overview
Q13. Bombay Phenotype and the Probability of Blood Type B in a Second Child IBO 2020: Theoretical 2
Extensions of Mendelian InheritanceMendel's Laws & Probability in Genetics
Q14. Identifying the First Limiting Reagent in a Multi-Cycle PCR Reaction IBO 2020: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Q15. Engineering Candida tropicalis Gene Disruptions to Boost Xylitol Production IBO 2020: Theoretical 2
Gene Regulation: Eukaryotic & Epigenetics
Q16. Diagnosing Missing DNA Replication Enzymes from Failed In Vitro Experiments IBO 2020: Theoretical 2
DNA Structure & Replication
Q17. Ranking Organism Genome Sizes from a Photo Panel IBO 2020: Theoretical 2
Chromosomal Variation: Number & StructureMajor Taxa Cross-Reference
Q18. Predicting Spore Genotype Frequencies from Yeast Meiosis IBO 2020: Theoretical 2
Mendel's Laws & Probability in GeneticsLinkage, Recombination & Genetic Mapping
Q19. Genotyping T-DNA Insertion Lines by PCR Band Pattern IBO 2020: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Q20. Reconstructing a Two-Gene Co-Dominance Model for Flower Color IBO 2020: Theoretical 2
Gene Interactions: Epistasis & Complementation Analysis
Q21. Which Animal Viruses Must Package an Enzyme Inside the Capsid IBO 2020: Theoretical 2
Translation & the Genetic CodeRecombinant DNA & Biotechnology Techniques
Q22. Planning a Two-Gene pBR322 Cloning Strategy with Compatible Restriction Sites IBO 2020: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Q23. Oocyte Attrition, Ovulation Fraction, and Maternal-Age Risk of Down Syndrome IBO 2020: Theoretical 2
Human Reproductive SystemCell Cycle, Mitosis & Meiosis
Q24. Interpreting Pressure-Volume Relationships Across the Cardiac Cycle IBO 2020: Theoretical 2
Cardiovascular Physiology
Q25. Linking Muscle Molecular Defects to Specific Contraction Abnormalities IBO 2020: Theoretical 2
Muscle Physiology
Q26. Interpreting Gene A and Gene B Function in Endochondral Ossification IBO 2020: Theoretical 2
Human Skeletal System
Q27. Testing How Honeybees Measure Flight Distance for the Waggle Dance IBO 2020: Theoretical 2
Animal CommunicationOrientation & Navigation
Q28. CYP2C19 Polymorphisms and Drug Metabolism of Omeprazole and Clopidogrel IBO 2020: Theoretical 2
Digestive & Metabolic PhysiologyPopulation Genetics & Hardy-Weinberg Equilibrium
Q29. Factors Driving Coronavirus Genome Variation and Cross-Species Transmission IBO 2020: Theoretical 2
Molecular Evolution & Neutral TheoryCoevolution & Species Interactions
Q30. Photoperiod, Growth Rate and the Timing of Red Leaf Formation in Amaranth IBO 2020: Theoretical 2
Photoperiodism, Vernalization & Flowering
Q31. Auxin, Cytokinin and Density Effects on Bud Formation in the Moss Physcomitrella IBO 2020: Theoretical 2
Plant Hormones
Q32. Turgor Pressure and Tissue Layer Mechanics in Explosive Seed Dispersal IBO 2020: Theoretical 2
Plant Stress Physiology & Defense
Q33. Diagnosing Whether a Tendril Is a Modified Leaf or Modified Stem IBO 2020: Theoretical 2
Plant Body Plans Across Major LineagesStem Anatomy
Q34. Two-Preceding-Leaf Rule for Leaf Positioning in the Fibonacci Spiral IBO 2020: Theoretical 2
Tropisms & Nastic MovementsPlant Hormones
Q35. Nitrogen Source and the Reductant Competition Behind CAQ in C3 versus C4 Plants IBO 2020: Theoretical 2
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Q36. Estimating Deleterious Mutations Passed On by Fathers of Different Ages IBO 2020: Theoretical 2
Molecular Evolution & Neutral TheoryPopulation Genetics & Hardy-Weinberg Equilibrium
Q37. Tracking Hox Cluster and Gene Duplication History Through Vertebrate Phylogeny IBO 2020: Theoretical 2
Chromosomal Variation: Number & StructureMolecular Systematics
Q38. Molecular Clock Estimates of Substitution Counts, Divergence Time and Domain-Specific Rates IBO 2020: Theoretical 2
Molecular Evolution & Neutral Theory
Q39. Identifying Unlabeled Cetartiodactyl DNA Samples from a Phylogenetic Sequence Alignment IBO 2020: Theoretical 2
Molecular SystematicsEvidence for Evolution
Q40. Tracing Membrane Origins in the Four-Membrane Plastids of Chlorarachniophytes IBO 2020: Theoretical 2
History of Life: Origin & Major TransitionsEndomembrane System & Protein Trafficking
Q41. Projecting a Three-Stage Population Forward and Finding the Extinction-Preventing Birth Rate IBO 2020: Theoretical 2
Population Genetics & Hardy-Weinberg Equilibrium
Q42. Matching Plant Morphological Plasticity Responses to Environmental Cues IBO 2020: Theoretical 2
Plant Stress Physiology & Defense
Q43. Direct and Inclusive Fitness in a Haplodiploid Hymenopteran Insect IBO 2020: Theoretical 2
Kin Selection, Altruism & Eusociality
Q44. Tracing Detrital and Grazing Food-Web Pathways and Cesium Bioaccumulation Timing IBO 2020: Theoretical 2
Ecology
Q45. Nitrogen and Phosphorus Accumulation Trajectories Through Primary Succession IBO 2020: Theoretical 2
Ecology
Q1. Alfalfa Mosaic Virus, m6A Demethylation & Viral Replication IBO 2022: Theoretical 1
Protein Structure, Folding & FunctionBiomolecular Analytical Techniques
Medium
Q2. Enzyme Kinetics, Time to Completion vs Temperature IBO 2022: Theoretical 1
Enzyme Kinetics & Regulation
Medium
Q3. Amylase Activity, Starch Hydrolysis at 50-70°C IBO 2022: Theoretical 1
Enzyme Kinetics & RegulationCarbohydrate Chemistry & Biology
Medium
Q4. Enzyme Inhibition, Substrate Concentration vs Rate Curves IBO 2022: Theoretical 1
Enzyme Kinetics & Regulation
Medium
Q5. Meselson-Stahl Experiment, DNA Replication Modes IBO 2022: Theoretical 1
DNA Structure & Replication
Hard
Q6. Cell Membrane Transport, Arrows X, Y, Z IBO 2022: Theoretical 1
Plasma Membrane Structure & Transport
Easy
Q7. Apoptosis, p53/Bax/Bcl-2 Pathway Under Hypoxia IBO 2022: Theoretical 1
Cell Junctions, Extracellular Matrix & Cell Death
Medium
Q8. Ethidium Bromide, DNA Binding and Intercalation IBO 2022: Theoretical 1
DNA Structure & ReplicationNucleotide & Nucleic Acid Chemistry
Medium
Q9. Organ-on-a-Chip, Lung-on-a-Chip & Pulmonary Oedema Model IBO 2022: Theoretical 1
Cell Junctions, Extracellular Matrix & Cell DeathRecombinant DNA & Biotechnology Techniques
Medium
Q10. 3D Bioprinting, Cell Viability, Bioluminescence, and Confocal Imaging IBO 2022: Theoretical 1
Recombinant DNA & Biotechnology TechniquesBiomolecular Analytical Techniques
Medium
Q11. Heart Decellularization, Fish vs. Rat Cannulation IBO 2022: Theoretical 1
Human Circulatory SystemRecombinant DNA & Biotechnology Techniques
Medium
Q12. iPSC/hESC Cardiomyocyte Grafts After Myocardial Infarction IBO 2022: Theoretical 1
Recombinant DNA & Biotechnology TechniquesCardiovascular Physiology
Hard
Q13. 3D Skin Substitute, Layered Tissue Engineering IBO 2022: Theoretical 1
Recombinant DNA & Biotechnology TechniquesHuman Integumentary System
Medium
Q14. Water Potential, Osmosis Between Three Plant Cells IBO 2022: Theoretical 1
Water Transport & Transpiration
Medium
Q15. Plant Life Cycle, Heterospory and Gametophyte Forms IBO 2022: Theoretical 1
Plant Body Plans Across Major Lineages
Medium
Q16. Flower Structure, Symmetry, Pollination, and Calyx IBO 2022: Theoretical 1
Flower Anatomy & Reproductive Structures
Easy
Q17. Plant Organ Modifications, Shoot vs. Leaf Origin IBO 2022: Theoretical 1
Stem AnatomyLeaf Anatomy
Medium
Q18. Mycorrhizal Symbiosis, Ecto-, Endo-, and Ectendomycorrhiza IBO 2022: Theoretical 1
Root AnatomyMineral Nutrition & Nutrient Uptake
Easy
Q19. Plant Life Cycles, Water-Dependent Fertilization IBO 2022: Theoretical 1
Plant Body Plans Across Major Lineages
Medium
Q20. Tree Age Estimation, Annual Ring Growth IBO 2022: Theoretical 1
Secondary Growth & Wood Anatomy
Hard
Q21. Biological Samples, Identifying Diverse Organisms IBO 2022: Theoretical 1
Biomolecular Analytical Techniques
Medium
Q22. Social Stress Response in Mice, Dominance Hierarchy IBO 2022: Theoretical 1
Aggression, Territoriality & Social Structure
Medium
Q23. Gut Microbiome, Bacterial Crossing of the Blood-Brain Barrier IBO 2022: Theoretical 1
Nervous System PhysiologyImmune Physiology
Hard
Q24. Comparative Liver Anatomy, Zebrafish vs. Human IBO 2022: Theoretical 1
Fish & Amphibian AnatomyMammalian Comparative Anatomy
Medium
Q25. Oxytocin and Cortisol, Touch vs. Voice Contact in Girls IBO 2022: Theoretical 1
Endocrine System Physiology
Medium
Q26. Cardiac Cycle, Valve Timing and Pressure Changes IBO 2022: Theoretical 1
Cardiovascular Physiology
Medium
Q27. Saiga Antelope, Nose Adaptations for Cold, Dust, and Signalling IBO 2022: Theoretical 1
Comparative ThermoregulationMating Systems & Sexual Selection
Easy
Q28. Carbon Dioxide Transport in the Blood IBO 2022: Theoretical 1
Respiratory Physiology
Medium
Q29. The Bohr Effect, Oxygen-Haemoglobin Dissociation IBO 2022: Theoretical 1
Respiratory Physiology
Medium
Q30. Bone Marrow Conversion, Red vs. Yellow Marrow With Age IBO 2022: Theoretical 1
Human Skeletal System
Medium
Q31. Retina Cell Layers, Direction of Light and Cell Types IBO 2022: Theoretical 1
Human Sensory Organs
Medium
Q32. Shiverer Mutation, Optic Nerve Myelin IBO 2022: Theoretical 1
Nervous System Physiology
Medium
Q33. Dormouse Litters, Growth Rate and Energy Intake IBO 2022: Theoretical 1
Locomotion & Energetics
Medium
Q34. Cichlid Fish, Anal Fin Egg-Spot Signalling IBO 2022: Theoretical 1
Mating Systems & Sexual Selection
Medium
Q35. Ninespine Stickleback, Sexual Dimorphism and Sneaker Males IBO 2022: Theoretical 1
Mating Systems & Sexual Selection
Medium
Q36. Aethia cristatella, Courtship Display on Rocks IBO 2022: Theoretical 1
Aggression, Territoriality & Social StructureMating Systems & Sexual Selection
Medium
Q37. ABO Blood Groups, H Antigen and the Bombay Phenotype IBO 2022: Theoretical 1
Pedigree Analysis & Human Genetic Disorders
Hard
Q38. Modes of Natural Selection, Frequency Distribution Curves IBO 2022: Theoretical 1
Natural Selection: Modes & Fitness
Medium
Q39. Mutation Rates, Asexual vs. Sexual Yeast Populations IBO 2022: Theoretical 1
Molecular Evolution & Neutral Theory
Hard
Q40. Elephants, LIF6, and Cancer Resistance IBO 2022: Theoretical 1
Molecular Evolution & Neutral TheoryCell Junctions, Extracellular Matrix & Cell Death
Medium
Q41. Angelman Syndrome, Genomic Imprinting Pedigree IBO 2022: Theoretical 1
Pedigree Analysis & Human Genetic DisordersExtranuclear & Non-Mendelian Inheritance
Hard
Q42. Thyrocyte Adenylyl Cyclase, TSH and VIP/PACAP Pathways IBO 2022: Theoretical 1
Endocrine System Physiology
Hard
Q43. Giraffe FGFRL1, Cardiovascular and Skeletal Adaptations IBO 2022: Theoretical 1
Cardiovascular PhysiologyMolecular Evolution & Neutral Theory
Medium
Q44. Macromutations and Morphogenesis, A1/A2/M Gene Model IBO 2022: Theoretical 1
Evolutionary Developmental Biology (Evo-Devo)
Hard
Q45. Drosophila Color Preference and Circadian Activity IBO 2022: Theoretical 1
Biological Rhythms
Medium
Q46. Three-Toed Sloth Fur Ecosystem, Moths, Algae, and Fungi IBO 2022: Theoretical 1
Coevolution & Species Interactions
Medium
Q47. Codling Moth, Temperature/Humidity Ecological Niche IBO 2022: Theoretical 1
Ecology
Hard
Q48. Sockeye Salmon, Life Stages and Chukchi Population Age Structure IBO 2022: Theoretical 1
Ecology
Medium
Q49. Biological Nitrogen Fixation, Diazotrophs and Nitrogenase IBO 2022: Theoretical 1
Mineral Nutrition & Nutrient Uptake
Easy
Q51. Cancer Cell Metabolism, Aerobic Glycolysis and the Warburg Effect IBO 2022: Theoretical 2
Bioenergetics & Central Metabolism Overview
Hard
Q52. Cryopyrin Inflammasome, Western Blot of WT and Mutant Variants IBO 2022: Theoretical 2
Immune Physiology
Hard
Q53. Telomerase, Mechanism of Telomere Extension IBO 2022: Theoretical 2
DNA Structure & Replication
Medium
Q54. NAD(P)H Fluorescence During the Aerobic-Anaerobic Transition in Yeast IBO 2022: Theoretical 2
Bioenergetics & Central Metabolism Overview
Hard
Q55. X-Irradiation of Yeast, NAD(P)H Fluorescence and Metabolic Recovery IBO 2022: Theoretical 2
Bioenergetics & Central Metabolism Overview
Hard
Q56. Lysosomal Exocytosis in Cancer Cells IBO 2022: Theoretical 2
Endomembrane System & Protein Trafficking
Medium
Q57. PIP2/PIP3 Signaling in T Cells, PTEN and Antigen Dose IBO 2022: Theoretical 2
Immune PhysiologyCell Signaling & Communication
Medium
Q58. TAK1 Kinase and Takinib, Competitive vs Non-Competitive Inhibition IBO 2022: Theoretical 2
Enzyme Kinetics & Regulation
Hard
Q59. Mitochondrial Innate Immunity, Yme1L, SLC25A33 and mtDNA Release IBO 2022: Theoretical 2
Mitochondria & Chloroplasts: Structure & Endosymbiotic OriginImmune Physiology
Hard
Q60. Alzheimer's Disease, APP Processing by α-, β- and γ-Secretases IBO 2022: Theoretical 2
Protein Structure, Folding & Function
Medium
Q61. RNA Virus Replication Cycles, Genome Classification IBO 2022: Theoretical 2
Nucleotide & Nucleic Acid Chemistry
Medium
Q62. Pine Needle Cross-Section, Resin Duct and Mesophyll IBO 2022: Theoretical 2
Leaf Anatomy
Easy
Q63. Land Plant Phylogeny, Evaluating Four Cladograms IBO 2022: Theoretical 2
Plant Body Plans Across Major Lineages
Medium
Q64. The C4 Rice Project, Engineering C4 Photosynthesis into a C3 Crop IBO 2022: Theoretical 2
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Medium
Q65. Arabidopsis Sun vs Shade Leaves, Cross-Section Comparison IBO 2022: Theoretical 2
Leaf Anatomy
Medium
Q66. Transpiration Rate Differences Between Leaf Surfaces IBO 2022: Theoretical 2
Stomatal Physiology & Gas Exchange
Easy
Q67. Root Water Transport Pathways, Apoplast vs Symplast IBO 2022: Theoretical 2
Water Transport & Transpiration
Medium
Q68. Pressure-Flow Model of Phloem Sucrose Transport IBO 2022: Theoretical 2
Phloem Transport & Translocation
Medium
Q69. Mechanosensitive Ion Channels, OSCA vs Piezo1 IBO 2022: Theoretical 2
Cell Signaling & Communication
Medium
Q70. Land Plant Phylogeny and Shared Derived Characters IBO 2022: Theoretical 2
History of Life: Origin & Major Transitions
Medium
Q71. Hippo Pathway Signaling in Blastocyst Implantation IBO 2022: Theoretical 2
Cell Signaling & Communication
Hard
Q72. Mechanisms of Synaptic Specificity IBO 2022: Theoretical 2
Nervous System Physiology
Easy
Q73. PD-1 Immune Checkpoint Signaling IBO 2022: Theoretical 2
Immune Physiology
Easy
Q74. Pathophysiology of Traumatic Brain Injury IBO 2022: Theoretical 2
Nervous System Physiology
Medium
Q75. Plasma Enzyme Diagnostics After Myocardial Infarction IBO 2022: Theoretical 2
Cardiovascular Physiology
Medium
Q76. Insulin and Glucagon Dynamics in Type 2 Diabetes IBO 2022: Theoretical 2
Endocrine System Physiology
Medium
Q77. Mitochondrial Calcium Handling in Synaptic Plasticity and Aging IBO 2022: Theoretical 2
Nervous System Physiology
Hard
Q78. Cellular Response to DNA Damage in Cancer IBO 2022: Theoretical 2
DNA Repair & Recombination
Medium
Q79. Primary vs Secondary Antibody Response IBO 2022: Theoretical 2
Immune Physiology
Medium
Q80. Dopamine and GABA Neuron Activity in Stress-Induced Anhedonia IBO 2022: Theoretical 2
Nervous System Physiology
Medium
Q81. Blue Light, Melanopsin and the Circadian Phase-Shift Response IBO 2022: Theoretical 2
Biological Rhythms
Medium
Q82. Experimental Design Limits, Herbal Treatment and Statin Co-Therapy IBO 2022: Theoretical 2
Cardiovascular Physiology
Medium
Q83. Gut Microbiome and Lifespan in Drosophila IBO 2022: Theoretical 2
Ecology
Hard
Q84. Dietary Fat, Sucrose and Cardiac Hypertrophy in Hypertensive Rats IBO 2022: Theoretical 2
Cardiovascular Physiology
Hard
Q85. The methuselah Mutation and Stress Resistance in Drosophila IBO 2022: Theoretical 2
Comparative Thermoregulation
Medium
Q86. Giant Panda Fecal-Smearing Behavior and the TRPM8 Cold Receptor IBO 2022: Theoretical 2
Mechanisms of Behavior
Medium
Q87. Rearing Environment and Social Bonds in Ravens IBO 2022: Theoretical 2
Development & Learning
Medium
Q88. Free Choice vs Random Union, Assortative Mating in Pigeons IBO 2022: Theoretical 2
Mating Systems & Sexual Selection
Medium
Q89. Amplexus and Sperm Competition in Newts IBO 2022: Theoretical 2
Mating Systems & Sexual Selection
Easy
Q90. Cannibalism and Larval-Stage Duration in Invasive Cane Toads IBO 2022: Theoretical 2
Foraging & Anti-Predator Behavior
Medium
Q91. Song Recognition Between Island Populations of Tree Finches IBO 2022: Theoretical 2
Animal Communication
Medium
Q92. Hawk-Dove-Retaliator Game Theory and Evolutionarily Stable Strategies IBO 2022: Theoretical 2
Aggression, Territoriality & Social Structure
Hard
Q93. Worker Sterility and Kin Selection in Social Insects IBO 2022: Theoretical 2
Kin Selection, Altruism & Eusociality
Medium
Q94. Canine Pedigree Analysis of a Monogenic Disease IBO 2022: Theoretical 2
Pedigree Analysis & Human Genetic Disorders
Medium
Q95. Hardy-Weinberg Calculations for Familial Mediterranean Fever IBO 2022: Theoretical 2
Population Genetics & Hardy-Weinberg Equilibrium
Hard
Q96. Transcriptome-Based Drug Repurposing, Infliximab Across Four Diseases IBO 2022: Theoretical 2
Immune Physiology
Hard
Q97. Telomerase-Dependent vs Alternative Telomere Lengthening in Testis IBO 2022: Theoretical 2
DNA Structure & Replication
Hard
Q98. Grape Domestication and Phylogeography from SNP Data IBO 2022: Theoretical 2
Genetic Drift, Gene Flow & Mutation
Medium
Q99. Competitive Displacement Between Two Hare Species in Newfoundland IBO 2022: Theoretical 2
Foraging & Anti-Predator Behavior
Medium
Q100. Cold-Exposure Duration, Acclimation and Mollusc Survival IBO 2022: Theoretical 2
Comparative Thermoregulation
Medium
Q1. Skeletal Muscle Energy Sources IBO 2023: Theoretical 1
Muscle Physiology
Medium
Q2. Smooth Muscle Contraction Dynamics IBO 2023: Theoretical 1
Muscle Physiology
Medium
Q3. Flow Cytometry of Mouse Blood IBO 2023: Theoretical 1
Biomolecular Analytical TechniquesImmune Physiology
Medium
Q5. Desert March Dehydration and SIADH IBO 2023: Theoretical 1
Homeostasis & OsmoregulationCardiovascular Physiology
Hard
Q6. Renal Clearance and Glomerular Filtration IBO 2023: Theoretical 1
Comparative Osmoregulation & Excretion
Hard
Q7. Archaeal Phylogeny and the Origin of Eukaryotes IBO 2023: Theoretical 1
History of Life: Origin & Major TransitionsCell Theory, Prokaryotes & Eukaryotes
Hard
Q8. Gram Staining, Monoderms, Diderms and Firmicute Evolution IBO 2023: Theoretical 1
Cell Theory, Prokaryotes & EukaryotesPhylogenetic Trees & Cladistics
Hard
Q10. Yeast Prion [GAR+] and Bacterial Metabolite Signaling IBO 2023: Theoretical 1
Gene Regulation: Eukaryotic & Epigenetics
Hard
Q11. Engineered Viral Capsids and Genome Packaging IBO 2023: Theoretical 1
Recombinant DNA & Biotechnology TechniquesProtein Structure, Folding & Function
Hard
Q12. Genome Size, Genetic Code and Alien DNA IBO 2023: Theoretical 1
Nucleotide & Nucleic Acid ChemistryTranslation & the Genetic Code
Hard
Q13. Bacterial 23S rRNA Gene Copy Number IBO 2023: Theoretical 1
Nucleotide & Nucleic Acid Chemistry
Medium
Q14. DNA Replication Origins and Rate IBO 2023: Theoretical 1
DNA Structure & Replication
Medium
Q15. Sea Turtle Temperature-Dependent Sex Determination IBO 2023: Theoretical 1
Sex Determination & Sex-Linked InheritanceEcology
Medium
Q16. Metabolic Scaling and Kleiber's Law IBO 2023: Theoretical 1
Comparative ThermoregulationLocomotion & Energetics
Medium
Q17. Community Similarity: Sorensen-Dice and Jaccard IBO 2023: Theoretical 1
Ecology
Medium
Q18. Ecosystem Tipping Points and Vegetation-Livestock Dynamics IBO 2023: Theoretical 1
Ecology
Hard
Q19. Foraging Energetics and Territory Defence IBO 2023: Theoretical 1
Foraging & Anti-Predator BehaviorAggression, Territoriality & Social Structure
Medium
Q20. Flycatcher Song Dialects and Species Discrimination IBO 2023: Theoretical 1
Animal Communication
Hard
Q21. Guppy Mate-Choice Copying IBO 2023: Theoretical 1
Mating Systems & Sexual Selection
Hard
Q22. Mendel's Round and Wrinkled Peas: PCR Analysis IBO 2023: Theoretical 1
Mendel's Laws & Probability in GeneticsRecombinant DNA & Biotechnology Techniques
Medium
Q23. Genomic Imprinting Pedigree IBO 2023: Theoretical 1
Pedigree Analysis & Human Genetic DisordersGene Regulation: Eukaryotic & Epigenetics
Hard
Q24. Identical-by-Descent Segments and Genetic Relatedness IBO 2023: Theoretical 1
Population Genetics & Hardy-Weinberg Equilibrium
Hard
Q25. Nucleotide Diversity and Selective Sweeps IBO 2023: Theoretical 1
Population Genetics & Hardy-Weinberg EquilibriumNatural Selection: Modes & Fitness
Hard
Q26. Transgenic Male Sterility and Herbicide Resistance IBO 2023: Theoretical 1
Mendel's Laws & Probability in GeneticsRecombinant DNA & Biotechnology Techniques
Hard
Q27. Dog Body Size and the IGF1 Locus IBO 2023: Theoretical 1
Molecular Evolution & Neutral Theory
Medium
Q28. Xylem Embolism and Hydraulic Safety Margins IBO 2023: Theoretical 1
Water Transport & Transpiration
Medium
Q29. Water Stress, Photosynthesis and Turgor IBO 2023: Theoretical 1
Water Transport & TranspirationPlant Stress Physiology & Defense
Medium
Q30. Wheat Nitrogen Assimilation Under Elevated CO2 IBO 2023: Theoretical 1
Mineral Nutrition & Nutrient UptakeCalvin Cycle, Photorespiration & C4/CAM Biochemistry
Hard
Q31. Plant Biology Assertion-Reason Questions IBO 2023: Theoretical 1
Light Reactions & PhotophosphorylationPlant Hormones
Easy
Q1. Desert Bat Adaptations IBO 2023: Theoretical 2
Comparative ThermoregulationForaging & Anti-Predator Behavior
Easy
Q2. Arabian Lizard Diversity IBO 2023: Theoretical 2
Comparative ThermoregulationMajor Taxa Cross-Reference
Medium
Q3. Shell Drilling Predation IBO 2023: Theoretical 2
Invertebrate Body Plans IIForaging & Anti-Predator Behavior
Medium
Q4. Whitefly Horizontal Gene Transfer IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology TechniquesCoevolution & Species Interactions
Medium
Q5. Angler Fish Immunity and Mating IBO 2023: Theoretical 2
Immune PhysiologyMating Systems & Sexual Selection
Hard
Q6. Missing Cell Types in Adults IBO 2023: Theoretical 2
Cell Theory, Prokaryotes & Eukaryotes
Easy
Q7. Elysia Kleptoplasty and Regeneration IBO 2023: Theoretical 2
Mitochondria & Chloroplasts: Structure & Endosymbiotic Origin
Medium
Q8. Chromatin DNase Sensitivity IBO 2023: Theoretical 2
Gene Regulation: Eukaryotic & EpigeneticsBiomolecular Analytical Techniques
Hard
Q9. Microglia and Memory Forgetting IBO 2023: Theoretical 2
Nervous System PhysiologyImmune Physiology
Medium
Q10. Cardiac Cell 14C Dating IBO 2023: Theoretical 2
Cardiovascular Physiology
Medium
Q11. Kartagener Syndrome IBO 2023: Theoretical 2
Cytoskeleton & Motor ProteinsRespiratory Physiology
Medium
Q12. Visual Pathway Interruptions IBO 2023: Theoretical 2
Nervous System PhysiologyHuman Sensory Organs
Medium
Q13. Lethal Temperature in Homeotherms IBO 2023: Theoretical 2
Comparative Thermoregulation
Medium
Q14. Submarine Atmosphere and Oxygen IBO 2023: Theoretical 2
Respiratory Physiology
Hard
Q15. Ventilation and Respiratory Gas Control IBO 2023: Theoretical 2
Respiratory Physiology
Hard
Q16. Cell Surface-to-Volume Ratio IBO 2023: Theoretical 2
Cell Theory, Prokaryotes & EukaryotesPlasma Membrane Structure & Transport
Medium
Q17. Glucose Oxidase and Enzyme Kinetics IBO 2023: Theoretical 2
Enzyme Kinetics & Regulation
Medium
Q18. Lactic Acid Fermentation IBO 2023: Theoretical 2
Bioenergetics & Central Metabolism Overview
Medium
Q19. cAMP Signaling and Caffeine IBO 2023: Theoretical 2
Cell Signaling & Communication
Medium
Q20. Gasdermin and Pyroptosis IBO 2023: Theoretical 2
Cell Junctions, Extracellular Matrix & Cell DeathImmune Physiology
Hard
Q21. Aconitase Mechanism IBO 2023: Theoretical 2
Bioenergetics & Central Metabolism OverviewEnzyme Kinetics & Regulation
Hard
Q22. Metformin and Complex I IBO 2023: Theoretical 2
Bioenergetics & Central Metabolism Overview
Medium
Q23. Nerve Conduction and Volume Conductor IBO 2023: Theoretical 2
Nervous System Physiology
Medium
Q24. C-STAR Blood Glucose Control IBO 2023: Theoretical 2
Endocrine System PhysiologyCell Signaling & Communication
Medium
Q25. Golden Gate Assembly Constructs IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Hard
Q26. T-DNA Southern Blot Analysis IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology TechniquesBiomolecular Analytical Techniques
Hard
Q27. Gene Regulation by Protein Y IBO 2023: Theoretical 2
Gene Regulation: Eukaryotic & Epigenetics
Medium
Q28. Ancient DNA Extraction IBO 2023: Theoretical 2
Biomolecular Analytical TechniquesNucleotide & Nucleic Acid Chemistry
Medium
Q29. Paulinella Chloroplast Endosymbiosis IBO 2023: Theoretical 2
Mitochondria & Chloroplasts: Structure & Endosymbiotic OriginHistory of Life: Origin & Major Transitions
Hard
Q30. Parasite-Mediated Competition in Squirrels IBO 2023: Theoretical 2
Coevolution & Species Interactions
Medium
Q31. Cryptic Aricia Butterfly Species IBO 2023: Theoretical 2
Speciation & Reproductive Isolation
Medium
Q32. Seabird Foraging and Niche Segregation IBO 2023: Theoretical 2
Foraging & Anti-Predator Behavior
Medium
Q33. Symbiodinium Nutrient Limitation IBO 2023: Theoretical 2
Coevolution & Species Interactions
Hard
Q34. Bonnet Macaque Population Demography IBO 2023: Theoretical 2
Natural Selection: Modes & Fitness
Medium
Q35. Primate Mating Systems IBO 2023: Theoretical 2
Mating Systems & Sexual Selection
Medium
Q36. Triceratops Skull Injuries IBO 2023: Theoretical 2
Evidence for Evolution
Medium
Q37. Group Selection Hypothesis IBO 2023: Theoretical 2
Natural Selection: Modes & Fitness
Medium
Q38. Sex Ratio Evolution IBO 2023: Theoretical 2
Natural Selection: Modes & FitnessMating Systems & Sexual Selection
Hard
Q39. RNA Editing Mechanisms IBO 2023: Theoretical 2
Transcription & RNA Processing
Medium
Q40. Drosophila Saturation Mutagenesis IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Easy
Q41. RFLP Analysis of Cat Mucolipidosis IBO 2023: Theoretical 2
Biomolecular Analytical TechniquesPedigree Analysis & Human Genetic Disorders
Hard
Q42. Variant Call Format Genomics IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology Techniques
Hard
Q43. Twin Studies and Heritability IBO 2023: Theoretical 2
Quantitative Genetics, Heritability & Inbreeding
Medium
Q44. Gene Drive Technology IBO 2023: Theoretical 2
Recombinant DNA & Biotechnology TechniquesSex Determination & Sex-Linked Inheritance
Hard
Q45. Mustard Seed Coat Color Inheritance IBO 2023: Theoretical 2
Gene Interactions: Epistasis & Complementation AnalysisExtranuclear & Non-Mendelian Inheritance
Hard
Q46. Mendelian Probability in Pea Pods IBO 2023: Theoretical 2
Mendel's Laws & Probability in Genetics
Hard
Q47. Neanderthal Ancient DNA and Gene Flow IBO 2023: Theoretical 2
Human Evolution & Hominid PhylogenyMolecular Evolution & Neutral Theory
Hard
Q48. Vascular Smooth Muscle and Atherosclerosis IBO 2023: Theoretical 2
Cell Signaling & CommunicationCardiovascular Physiology
Easy
Q49. Lacandonia Flower ABC Model IBO 2023: Theoretical 2
Flower Anatomy & Reproductive Structures
Medium
Q50. Phytochrome Thermosensing IBO 2023: Theoretical 2
Plant HormonesTropisms & Nastic Movements
Hard
Q51. C3 vs C4 Photosynthesis IBO 2023: Theoretical 2
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Medium
Q52. Phloem Transport Under Water Stress IBO 2023: Theoretical 2
Phloem Transport & TranslocationWater Transport & Transpiration
Medium
Q53. Hydrogen Water and Banana Ripening IBO 2023: Theoretical 2
Plant Hormones
Medium
Q54. Climate Change Effects on Rapeseed Oil IBO 2023: Theoretical 2
Plant Stress Physiology & Defense
Medium
Q55. Extrafloral Nectaries and Herbivory Defense IBO 2023: Theoretical 2
Plant Stress Physiology & DefenseCoevolution & Species Interactions
Medium
Q56. Rubber Tree Stem Diameter Dynamics IBO 2023: Theoretical 2
Water Transport & TranspirationSecondary Growth & Wood Anatomy
Medium
Q57. Root Hairs and Mycorrhizal Fungi IBO 2023: Theoretical 2
Mineral Nutrition & Nutrient Uptake
Hard
Q1. Tulip Parsimony and Morphological Characters IBO 2024: Theoretical A
Phylogenetic Trees & Cladistics
Hard
Q2. Strigiformes (Owls) Phylogenetic Identification IBO 2024: Theoretical A
Phylogenetic Trees & Cladistics
Hard
Q3. Bacterial Phylogenomics (RNA Polymerase vs Transposase) IBO 2024: Theoretical A
Molecular Systematics
Medium
Q4. Tumor Microenvironment: OCR and Extracellular pH IBO 2024: Theoretical A
Bioenergetics & Central Metabolism Overview
Easy
Q5. Antibody Mutagenesis and Cardiac Glycoside Binding (ELISA) IBO 2024: Theoretical A
Protein Structure, Folding & Function
Hard
Q6. Ramachandran Plot and Peptide Bond Geometry IBO 2024: Theoretical A
Protein Structure, Folding & Function
Medium
Q7. Pentose Phosphate Pathway (PPP) IBO 2024: Theoretical A
Bioenergetics & Central Metabolism Overview
Medium
Q8. IGF2-H19 Imprinting and CTCF Loops IBO 2024: Theoretical A
Gene Regulation: Eukaryotic & Epigenetics
Hard
Q9. ATAD1 Mitochondrial ATPase (Cryo-EM Study) IBO 2024: Theoretical A
Protein Structure, Folding & Function
Hard
Q10. Magnetotactic Bacteria Navigation IBO 2024: Theoretical A
Cell Theory, Prokaryotes & Eukaryotes
Hard
Q11. Directed Evolution of Enzyme D (NADH-Dependent) IBO 2024: Theoretical A
Recombinant DNA & Biotechnology Techniques
Easy
Q12. DMSO₄ Poisoning Case Study IBO 2024: Theoretical A
Plasma Membrane Structure & Transport
Medium
Q13. Nitrogen Limitation of Legumes in Steppes IBO 2024: Theoretical A
Ecology
Medium
Q14. Latitudinal Diversity Gradient: Three Hypotheses IBO 2024: Theoretical A
Ecology
Hard
Q15. ENSO and Ecosystem Effects IBO 2024: Theoretical A
Ecology
Hard
Q16. Fractal Geometry and Scale-Dependent Resource Availability IBO 2024: Theoretical A
Ecology
Hard
Q17. Water Scarcity Index (Rws) and Solutions IBO 2024: Theoretical A
Ecology
Medium
Q18. Animal Road Barrier Effect (Traffic Behavior Types) IBO 2024: Theoretical A
Mechanisms of Behavior
Medium
Q19. Cumulative Cultural Evolution in Rock Pigeons IBO 2024: Theoretical A
Development & Learning
Hard
Q20. Haploid/Diploid Organisms and Multi-Allele Genetics IBO 2024: Theoretical A
Mendel's Laws & Probability in Genetics
Medium
Q21. Out-of-Africa Human Genetic Diversity and Effective Population Size IBO 2024: Theoretical A
Genetic Drift, Gene Flow & MutationHuman Evolution & Hominid Phylogeny
Medium
Q22. ADH1B Allele Geography and Ethanol Metabolism IBO 2024: Theoretical A
Natural Selection: Modes & Fitness
Medium
Q23. Drosophila Allele Frequency Experiment and Stabilizing Selection IBO 2024: Theoretical A
Natural Selection: Modes & FitnessPopulation Genetics & Hardy-Weinberg Equilibrium
Medium
Q24. Codon Usage Bias IBO 2024: Theoretical A
Translation & the Genetic Code
Easy
Q25. Mitochondrial RNase P Mutations and COXPD54 IBO 2024: Theoretical A
Pedigree Analysis & Human Genetic DisordersMitochondria & Chloroplasts: Structure & Endosymbiotic Origin
Hard
Q26. Mass Extinctions and Carbon Cycle Perturbations IBO 2024: Theoretical A
Macroevolutionary Patterns & Mass Extinctions
Hard
Q27. Beta-Lactamase Mutational Trajectories and Epistasis IBO 2024: Theoretical A
Gene Interactions: Epistasis & Complementation Analysis
Hard
Q28. Distribution of Fitness Effects and Effective Population Size IBO 2024: Theoretical A
Genetic Drift, Gene Flow & Mutation
Hard
Q29. Endogenous Retroviruses and Retrotransposons IBO 2024: Theoretical A
DNA Repair & Recombination
Medium
Q30. Gibberellin Transport and Root Endodermis Suberization IBO 2024: Theoretical A
Plant HormonesRoot Anatomy
Hard
Q31. Photorespiration Pathway IBO 2024: Theoretical A
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Medium
Q32. Poaceae Stomata Synchronization Mechanism IBO 2024: Theoretical A
Stomatal Physiology & Gas Exchange
Hard
Q33. Xanthophyll Cycle and Photoprotection IBO 2024: Theoretical A
Light Reactions & Photophosphorylation
Medium
Q34. Maize Leaf Carbohydrate Allocation IBO 2024: Theoretical A
Phloem Transport & Translocation
Medium
Q35. Sequoia Tree Water Use Strategies IBO 2024: Theoretical A
Water Transport & Transpiration
Hard
Q36. Aquatic Carbon Uptake IBO 2024: Theoretical A
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Medium
Q37. Root Water Movement and Osmotic Regulation IBO 2024: Theoretical A
Root Anatomy
Medium
Q38. ECG Interpretation IBO 2024: Theoretical A
Cardiovascular Physiology
Hard
Q39. Snow Leopard Hemoglobin at High Altitude IBO 2024: Theoretical A
Respiratory Physiology
Medium
Q40. Circadian Misalignment in Mice IBO 2024: Theoretical A
Biological Rhythms
Medium
Q41. Octopus Active Sleep and Circadian Control IBO 2024: Theoretical A
Biological Rhythms
Medium
Q42. Electric Eel Prey Detection IBO 2024: Theoretical A
Foraging & Anti-Predator Behavior
Medium
Q43. Saiga Nasal Anatomy and Wolf Predation IBO 2024: Theoretical A
Mammalian Comparative AnatomyForaging & Anti-Predator Behavior
Hard
Q44. TLR7/8 Activation in Sperm Sex Sorting IBO 2024: Theoretical A
Reproductive Physiology
Easy
Q45. Vascularized Cardiac Tissue In Vitro IBO 2024: Theoretical A
Cardiovascular Physiology
Medium
Q46. Channelrhodopsin-2 (ChR2) in Hippocampal Neurons IBO 2024: Theoretical A
Nervous System Physiology
Hard
Q47. Cost of Transport in Locomotion IBO 2024: Theoretical A
Locomotion & Energetics
Hard
Q48. Helium Dilution Test for Residual Volume IBO 2024: Theoretical A
Respiratory Physiology
Hard
Q49. Esophageal Doppler Monitoring IBO 2024: Theoretical A
Cardiovascular Physiology
Hard
Q50. Countercurrent System and Nephron Function IBO 2024: Theoretical A
Comparative Osmoregulation & Excretion
Medium
Q1. Dichotomous Key Branching & Taxonomic Resolution IBO 2024: Theoretical B
Taxonomic Keys & Identification
Medium
Q2. Red Deer mtDNA Phylogeny & Bootstrap Support IBO 2024: Theoretical B
Molecular Systematics
Medium
Q3. BRCA1/53BP1 and DNA Double-Strand Break Repair Pathway Choice IBO 2024: Theoretical B
DNA Repair & Recombination
Hard
Q4. Calcium Channel Signaling in Pancreatic Beta Cells IBO 2024: Theoretical B
Cell Signaling & Communication
Medium
Q5. Ketogenic Diet Metabolism and Catecholamine Seizure Latency IBO 2024: Theoretical B
Bioenergetics & Central Metabolism Overview
Hard
Q6. ProQC, Synthetic Toehold-Switch Quality Control of Translation IBO 2024: Theoretical B
Recombinant DNA & Biotechnology Techniques
Easy
Q7. DNA Fiber Assay and Replication Fork Progression IBO 2024: Theoretical B
DNA Structure & Replication
Hard
Q8. Identifying DNA-Metabolism Enzymes from a Gel Assay IBO 2024: Theoretical B
Biomolecular Analytical Techniques
Hard
Q9. Compound X, Polyploidy, and Checkpoint Kinases A/B IBO 2024: Theoretical B
Cell Cycle, Mitosis & Meiosis
Medium
Q10. Heterodimer Formation, Ligand Signaling, and Stem Cell Differentiation IBO 2024: Theoretical B
Cell Signaling & CommunicationGene Regulation: Eukaryotic & Epigenetics
Hard
Q11. Proteasome vs. Lysosome Degradation and Protein Half-Life IBO 2024: Theoretical B
Endomembrane System & Protein Trafficking
Medium
Q12. FRET-Based Protease Activity and Inhibitor Mechanism IBO 2024: Theoretical B
Biomolecular Analytical Techniques
Hard
Q13. Shelterin, the T-loop, and Chromosome Bridge Formation IBO 2024: Theoretical B
DNA Repair & RecombinationCell Cycle, Mitosis & Meiosis
Hard
Q14. Aral Sea Food-Chain Restoration and Salinity Tolerance IBO 2024: Theoretical B
Ecology
Medium
Q15. Lotka-Volterra Competition Lines and Coexistence Outcomes IBO 2024: Theoretical B
Ecology
Hard
Q16. Niche Dimensions and Stipa capillata Drought Adaptation IBO 2024: Theoretical B
Ecology
Medium
Q17. Incompatible Insect Technique and Wolbachia-Induced Cytoplasmic Incompatibility IBO 2024: Theoretical B
Ecology
Medium
Q18. Ant Invasion, Visibility, and a Lion-Zebra-Buffalo Trophic Cascade IBO 2024: Theoretical B
Ecology
Medium
Q19. Heat-Balling Honeybee Defense Against Hornets IBO 2024: Theoretical B
Foraging & Anti-Predator Behavior
Medium
Q20. Female Body Mass, Male Fighting, and Mating Outcomes in Crickets IBO 2024: Theoretical B
Mating Systems & Sexual Selection
Medium
Q21. Cannibalism Probability and Injury Bias in Japanese Mitten Crabs IBO 2024: Theoretical B
Foraging & Anti-Predator Behavior
Hard
Q22. Genomic Imprinting at the IGF2-H19 Locus IBO 2024: Theoretical B
Extranuclear & Non-Mendelian Inheritance
Hard
Q23. ACE2/CTS1 Mutations and Multicellularity in Yeast IBO 2024: Theoretical B
Extensions of Mendelian Inheritance
Medium
Q24. Robertsonian Translocation and Chromosome 14/21 Anomalies IBO 2024: Theoretical B
Chromosomal Variation: Number & Structure
Hard
Q25. X-Linked Trait Allele Mixing and Pedigree Probability IBO 2024: Theoretical B
Sex Determination & Sex-Linked InheritancePopulation Genetics & Hardy-Weinberg Equilibrium
Hard
Q26. Intratumor Heterogeneity and Clonal Evolution Under Treatment IBO 2024: Theoretical B
Natural Selection: Modes & Fitness
Medium
Q27. PCR Mapping of Genomic Rearrangements in Genes H and K IBO 2024: Theoretical B
Chromosomal Variation: Number & Structure
Hard
Q28. Epistasis Between Two Hair-Pigmentation Genes IBO 2024: Theoretical B
Gene Interactions: Epistasis & Complementation Analysis
Hard
Q29. Cas9 Target Sites, Donor Design, and Mutation Severity IBO 2024: Theoretical B
Recombinant DNA & Biotechnology Techniques
Medium
Q30. Linked Genes Controlling Fruit Fly Wing Pigmentation IBO 2024: Theoretical B
Linkage, Recombination & Genetic Mapping
Hard
Q31. Linkage Disequilibrium Between M* and Flanking Loci R/Q IBO 2024: Theoretical B
Linkage, Recombination & Genetic Mapping
Medium
Q32. Venus Flytrap Closure, Temperature and Chemical Effects IBO 2024: Theoretical B
Tropisms & Nastic Movements
Medium
Q33. PtrWOX4a and PtrVCS2 in Vascular Cambium Proliferation IBO 2024: Theoretical B
Secondary Growth & Wood Anatomy
Medium
Q34. GAPLESS Proteins and Apoplastic Transport in Roots IBO 2024: Theoretical B
Root Anatomy
Medium
Q35. Phytochrome B States, Temperature, and Nuclear Bodies IBO 2024: Theoretical B
Photoperiodism, Vernalization & Flowering
Medium
Q36. CONSTANS, Photoperiod, and Seed Mass IBO 2024: Theoretical B
Photoperiodism, Vernalization & Flowering
Medium
Q37. Auxin Transport and Apical Dominance IBO 2024: Theoretical B
Plant Hormones
Hard
Q38. Chemical A, Gibberellin, and Wheat Seed Germination IBO 2024: Theoretical B
Seed Germination & Dormancy Physiology
Medium
Q39. Intermittent Claudication and Cardiovascular Drug Treatments IBO 2024: Theoretical B
Cardiovascular Physiology
Medium
Q40. Pharmacokinetics, Absorption, Distribution, Metabolism, Excretion IBO 2024: Theoretical B
Digestive & Metabolic Physiology
Easy
Q41. Burmese Python Heart Mass Changes After Feeding IBO 2024: Theoretical B
Cardiovascular Physiology
Medium
Q42. The Starling Equation and Capillary Fluid Exchange IBO 2024: Theoretical B
Cardiovascular Physiology
Medium
Q43. Liver Lobule Zonation and Bile Flow IBO 2024: Theoretical B
Digestive & Metabolic Physiology
Medium
Q44. Bee Thermoregulation and Body-Size Scaling IBO 2024: Theoretical B
Comparative Thermoregulation
Hard
Q45. COPD Lung Volume Changes and Pressure-Volume Curves IBO 2024: Theoretical B
Respiratory Physiology
Hard
Q46. Osmotic and Chemical Stress in a Marine Tardigrade IBO 2024: Theoretical B
Comparative Osmoregulation & Excretion
Hard
Q47. Cancer Immunotherapy and Checkpoint Inhibitors IBO 2024: Theoretical B
Immune Physiology
Medium
Q48. mRNA Nucleotide Modifications and Vaccine Design IBO 2024: Theoretical B
Immune Physiology
Medium
Q49. CCHa1, Enteroendocrine Cells, and Sleep Arousal in Drosophila IBO 2024: Theoretical B
Nervous System Physiology
Hard
Q50. Bicoid, Exuperantia, and Body Axis Determination in Drosophila IBO 2024: Theoretical B
Evolutionary Developmental Biology (Evo-Devo)
Medium
Q1. Protein Tertiary Structure Interactions INBO 2026: Theory
Protein Structure, Folding & Function
Medium
Q2. Plasmid Processing Enzyme (Gel Electrophoresis) INBO 2026: Theory
Recombinant DNA & Biotechnology Techniques
Medium
Q3. Membrane Fluidity and Gel-to-Fluid Transition INBO 2026: Theory
Lipids & Membrane Biochemistry
Hard
Q4. Conformational Entropy and Free Energy INBO 2026: Theory
Bioenergetics & Central Metabolism Overview
Medium
Q5. Suppressor tRNA and Stop Codon Readthrough INBO 2026: Theory
Translation & the Genetic Code
Hard
Q6. Gibberellic Acid and Light Effects on Hypocotyl Growth INBO 2026: Theory
Plant Hormones
Medium
Q7. Apical Dominance and Auxiliary Bud Dormancy INBO 2026: Theory
Plant Hormones
Easy
Q9. Phloem Sap Exudation and Light Dependence INBO 2026: Theory
Phloem Transport & Translocation
Medium
Q10. Rigor Mortis and ATP Depletion INBO 2026: Theory
Muscle Physiology
Easy
Q11. Homeotherm Heat Production and Loss INBO 2026: Theory
Comparative Thermoregulation
Medium
Q12. Bat Kidney Morphology and Diet INBO 2026: Theory
Comparative Osmoregulation & Excretion
Hard
Q13. lac Operon Regulation (Glucose and Lactose) INBO 2026: Theory
Gene Regulation: Prokaryotic
Medium
Q14. Cytogenetic Analysis of Sex Chromosome Abnormalities INBO 2026: Theory
Cell Cycle, Mitosis & Meiosis
Hard
Q15. Food Hoarding vs Fat Storage Under Uncertainty INBO 2026: Theory
Foraging & Anti-Predator Behavior
Medium
Q16. Navigation in Migratory Animals INBO 2026: Theory
Orientation & Navigation
Easy
Q17. Global Hydrological Cycle Turnover Times INBO 2026: Theory
Ecology
Hard
Q18. Carbon Cycle Flux Ranking INBO 2026: Theory
Ecology
Medium
Q19. Speckled Wood Butterfly Territorial Strategy INBO 2026: Theory
Aggression, Territoriality & Social Structure
Medium
Q20. Migration Cost Minimization Strategies INBO 2026: Theory
Orientation & Navigation
Easy
Q21. Convergent Evolution in Desert Plants INBO 2026: Theory
Evidence for Evolution
Easy
Q22. Cladogram Group Classification INBO 2026: Theory
Phylogenetic Trees & Cladistics
Medium
Q23. Gene Size, Introns and mRNA Analysis INBO 2026: Theory
Transcription & RNA Processing
Medium
Q24. Transcription Factor Activation Pathway INBO 2026: Theory
Gene Regulation: Eukaryotic & Epigenetics
Hard
Q25. Degenerate Oligonucleotide Probe Design INBO 2026: Theory
Recombinant DNA & Biotechnology Techniques
Hard
Q26. Protein Molecules in a Hepatocyte INBO 2026: Theory
Protein Structure, Folding & Function
Hard
Q27. Restriction Enzyme Mapping INBO 2026: Theory
Recombinant DNA & Biotechnology Techniques
Hard
Q28. Gaucher Disease GCase Mutation Analysis INBO 2026: Theory
Protein Structure, Folding & Function
Hard
Q29. Proteolytic Enzyme Substrate Specificity INBO 2026: Theory
Enzyme Kinetics & Regulation
Hard
Q30. Plant Biomolecular Composition Matching INBO 2026: Theory
Carbohydrate Chemistry & Biology
Medium
Q31. Plant Cell Water Potential Components INBO 2026: Theory
Water Transport & Transpiration
Hard
Q32. Thermal Acclimation and Photosynthesis in Arctic Plants INBO 2026: Theory
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Hard
Q33. Plant Photosynthetic Temperature Response INBO 2026: Theory
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Medium
Q34. Auxin-Mediated Phototropism Experiments INBO 2026: Theory
Plant Hormones
Medium
Q35. Calvin Cycle Intermediate Stoichiometry INBO 2026: Theory
Calvin Cycle, Photorespiration & C4/CAM Biochemistry
Hard
Q36. Mammalian Vision: Skull Morphology and Retinal Composition INBO 2026: Theory
Mammalian Comparative Anatomy
Hard
Q37. Nernst Equation Membrane Potential INBO 2026: Theory
Nervous System Physiology
Medium
Q38. Corticotropin Releasing Hormone in Pregnancy and Amphibian Development INBO 2026: Theory
Endocrine System Physiology
Hard
Q39. Enterocyte Ion Transport and Oral Rehydration INBO 2026: Theory
Digestive & Metabolic Physiology
Medium
Q40. Organ Weight-Specific Basal Metabolic Rate INBO 2026: Theory
Comparative Thermoregulation
Medium
Q41. Bohr and Haldane Effects in Fetal-Maternal Gas Exchange INBO 2026: Theory
Respiratory Physiology
Hard
Q42. Parthenogenesis in Whiptail Lizards INBO 2026: Theory
Reproductive Physiology
Medium
Q43. Polygenic Inheritance of Plant Height INBO 2026: Theory
Quantitative Genetics, Heritability & Inbreeding
Hard
Q44. RFLP Pedigree Analysis INBO 2026: Theory
Recombinant DNA & Biotechnology Techniques
Hard
Q45. Multiple Alleles in Mallard Duck Plumage INBO 2026: Theory
Extensions of Mendelian Inheritance
Medium
Q46. Epistatic Coat Color in Rodents INBO 2026: Theory
Gene Interactions: Epistasis & Complementation Analysis
Hard
Q47. X-linked Lesch-Nyhan Syndrome Probability INBO 2026: Theory
Sex Determination & Sex-Linked Inheritance
Hard
Q48. Genetic Drift Simulation in Small Populations INBO 2026: Theory
Genetic Drift, Gene Flow & Mutation
Medium
Q49. Types of Natural Selection on Allele Frequency INBO 2026: Theory
Natural Selection: Modes & Fitness
Medium
Q50. Tropical Seedling Shade Tolerance INBO 2026: Theory
Ecology
Medium
Q51. Risk-Sensitive Foraging Under Energy Stress INBO 2026: Theory
Foraging & Anti-Predator Behavior
Hard
Q52. Leaf Solar Tracking and Radiation INBO 2026: Theory
Tropisms & Nastic Movements
Medium
Q53. American Redstart Song Modes and Pairing INBO 2026: Theory
Animal Communication
Medium
Q54. Island vs Mainland Hare Population Dynamics INBO 2026: Theory
Ecology
Medium
Q55. Digger Bee Alternative Mating Strategies INBO 2026: Theory
Mating Systems & Sexual Selection
Hard
Q56. Cichlid Fish Agonistic Behavior and Weight Asymmetry INBO 2026: Theory
Aggression, Territoriality & Social Structure
Hard
Q57. Adaptive Significance of Bird Behavioral Traits INBO 2026: Theory
Animal Communication
Medium
Q58. Mollusc Clade Feature Identification INBO 2026: Theory
Invertebrate Body Plans II
Medium
Q59. Animal Phylogeny Evolutionary Traits INBO 2026: Theory
Phylogenetic Trees & Cladistics
Hard
Q1. Sample Question 1 (placeholder) TBO 2023: First Stage
Q2. Sample Question 2 (placeholder) TBO 2023: First Stage
Q3. Sample Question 3 (placeholder) TBO 2023: First Stage