A Unity and Diversity

A1.2 Nucleic acids

A2.1 Origins of cells

A2.2 Cell structure

A2.3 Viruses [HL only]

A3.1 Diversity of organisms

A3.2 Classification and cladistics [HL only]

A4.1 Evolution and speciation

A4.2 Conservation of biodiversity

B Form and Function

B1.1 Carbohydrates and lipids

B1.2 Proteins

B2.1 Membranes and membrane transport

B2.2 Organelles and compartmentalization

B2.3 Cell specialization

B3.1 Gas exchange

B3.2 Transport

B3.3 Muscle and motility [HL only]

B4.1 Adaptation to environment

B4.2 Ecological niches

C Interaction and Interdependence

C1.1 Enzymes and metabolism

C1.2 Cell respiration

C1.3 Photosynthesis

C2.1 Chemical signalling [HL only]

C2.2 Neural signalling

C3.1 Integration of body systems

C3.2 Defence against disease

C4.1 Populations and communities

C4.2 Transfers of energy and matter

D Continuity and Change

D1.1 DNA replication

D1.2 Protein synthesis

D1.3 Mutation and gene editing

D2.1 Cell and nuclear division

D2.2 Gene expression [HL only]

D2.3 Water potential

D3.1 Reproduction

D3.2 Inheritance

D3.3 Homeostasis

D4.1 Natural selection

D4.2 Stability and change

D4.3 Climate change

IB Biology HL Question Bank

Browse IB Biology HL practice questions by topic across the four syllabus themes, including higher-level extensions. Check available mark-scheme points as you revise.

Exam analysis

HL · 2010–2025

Past-paper evidence across IB Biology clusters around structure-function relationships, molecular information, regulated interactions and evolutionary change. The course pattern is strongest when students connect mechanisms across levels of organisation rather than learning each topic as isolated facts.

Papers analysed117in the analysed sample

Latest appearanceNovember 2025

Tagged question parts2574

Paper types5

Most tested syllabus areas

C Interaction and Interdependence115 papers
D Continuity and Change115 papers
B Form and Function114 papers
A Unity and Diversity110 papers

117 papers analysed · Tagging incomplete

Unity and Diversity

A1.1 WaterA1.2 Nucleic acidsA2.1 Origins of cellsA2.2 Cell structureA2.3 Viruses [HL only]A3.1 Diversity of organismsA3.2 Classification and cladistics [HL only]A4.1 Evolution and speciationA4.2 Conservation of biodiversity

Form and Function

B1.1 Carbohydrates and lipidsB1.2 ProteinsB2.1 Membranes and membrane transportB2.2 Organelles and compartmentalizationB2.3 Cell specializationB3.1 Gas exchangeB3.2 TransportB3.3 Muscle and motility [HL only]B4.1 Adaptation to environmentB4.2 Ecological niches

Interaction and Interdependence

C1.1 Enzymes and metabolismC1.2 Cell respirationC1.3 PhotosynthesisC2.1 Chemical signalling [HL only]C2.2 Neural signallingC3.1 Integration of body systemsC3.2 Defence against diseaseC4.1 Populations and communitiesC4.2 Transfers of energy and matter

Continuity and Change

D1.1 DNA replicationD1.2 Protein synthesisD1.3 Mutation and gene editingD2.1 Cell and nuclear divisionD2.2 Gene expression [HL only]D2.3 Water potentialD3.1 ReproductionD3.2 InheritanceD3.3 HomeostasisD4.1 Natural selectionD4.2 Stability and changeD4.3 Climate change

Frequently Asked Questions

Which syllabus scope does the IB Biology HL question bank use?

The topic directory follows the Biology syllabus for first assessment 2025. Choose an HL topic or syllabus statement to study shared content and higher-level extensions.

How can I find IB Biology HL practice questions by topic?

Choose a topic from the four-theme directory or the syllabus sidebar. Narrow the scope to the knowledge point you want to revise before opening its questions.

What answer support is available?

Review the answer and mark guidance available for the question you open. Compare biological terminology, evidence and linked reasoning with the available scoring points; the support varies between questions.

How is the Question Bank different from Practice and the course guide?

The Question Bank helps you browse questions for a chosen syllabus scope. Practice lets you configure a practice session. The IB Biology HL course guide explains the syllabus, assessment and study methods.