IBDP Biology SL 2025

IBDP Biology

The scale of life in biology ranges from the molecules and cells of organisms to ecosystems and the biosphere. This way of considering complex systems as simpler components an approach known as reductionism—makes systems more manageable to study. It is the foundation of controlled experiments and has thus enabled major discoveries, but it provides an incomplete view of life. At each level of biological organization, different properties exist. Living systems are based on interactions, interdependence and integration of components between all levels of biological organization. A student of biology should gain not only a conceptual understanding of the subject, but also an awareness of how biologists construct knowledge claims and the limitations of these methods.

Exam Style Practice Questions, Notes and Past Paper for IBDP Biology 2025


Past Years Papers

IBDP Biology SL and HL Past Papers

Changes in Syllabus for IBDP Biology First Assessment 2025

Assessment for New IBDP Biology,  will only sit two external examinations.

Paper 1A includes multiple-choice questions on the syllabus.

paper 1B includes data-based questions that are syllabus related, addressing all themes.

Paper 2A includes data-based questions from unfamiliar contexts and short-answer questions.

Paper 2B includes extended-response questions that focus on holistic knowledge and understanding of a wide range of syllabus content, skills, concepts and understandings.

Other changes include the removal of the option topics (neurobiology and behaviour, biotechnology and informatics, ecology and conservation and human physiology).

From the current four options some of the content was incorporated into the course at either standard level or higher level.

Students are allowed to use Calculator even in Paper 1

Syllabus Framework for IBDP Biology First Assessment 2025

The biology syllabus comprises four themes, each made up of two concepts. Each theme is a lens through which the syllabus content can be viewed.

  • Theme A: Unity and diversity
  • Theme B: Form and function
  • Theme C: Interaction and interdependence
  • Theme D: Continuity and change

The arrangement of syllabus content follows four levels of biological organization, which also serve as conceptual lenses.

  • Level 1: Molecules
  • Level 2: Cells
  • Level 3: Organisms
  • Level 4: Ecosystems

Syllabus for IBDP Biology First Assessment 2025

A. Unity and diversity

  • 1. Molecules
    • A1.1 Water
    • A1.2 Nucleic acids
  • 2. Cells
    • A2.1 Origins of cells [HL only]
    • A2.2 Cell structure
    • A2.3 Viruses [HL only]
  • 3. Organisms
    • A3.1 Diversity of organisms
    • A3.2 Classification and cladistics [HL only]
  • 4. Ecosystems
    • A4.1 Evolution and speciation
    • A4.2 Conservation of biodiversity

B. Form and function

  • 1. Molecules
    • B1.1 Carbohydrates and lipids
    • B1.2 Proteins
  • 2. Cells
    • B2.1 Membranes and membrane transport
    • B2.2 Organelles and compartmentalization
    • B2.3 Cell specialization
  • 3. Organisms
    • B3.1 Gas exchange
    • B3.2 Transport
    • B3.3 Muscle and motility [HL only]
  • 4. Ecosystems
    • B4.1 Adaptation to environment
    • B4.2 Ecological niches

C.  Interaction and interdependence

  • 1. Molecules
    • C1.1 Enzymes and metabolism
    • C1.2 Cell respiration
    • C1.3 Photosynthesis
  • 2. Cells
    • C2.1 Chemical signaling [HL only]
    • C2.2 Neural signaling
  • 3. Organisms
    • C3.1 Integration of body systems
    • C3.2 Defence against disease
  • 4. Ecosystems
    • C4.1 Populations and communities
    • C4.2 Transfers of energy and matter

D. Continuity and change

  • 1. Molecules
    • D1.1 DNA replication
    • D1.2 Protein synthesis
    • D1.3 Mutations and gene editing
  • 2. Cells
    • D2.1 Cell and nuclear division
    • D2.2 Gene expression [HL only]
    • D2.3 Water potential
  • 3. Organisms
    • D3.1 Reproduction
    • D3.2 Inheritance
    • D3.3 Homeostasis
  • 4. Ecosystems
    • D4.1 Natural selection
    • D4.2 Stability and change
    • D4.3 Climate change
Scroll to Top