IBDP Biology 2025 SL & HL : Study Notes – All Topics

DP Physics 2025DP Maths DP Chemistry 2025DP Biology 2025

A. Unity and diversity

1. Molecules
- A1.1 Water
- A1.2 Nucleic acids
2. Cells
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
3. Organisms
4. Ecosystems
- B4.1 Adaptation to environment
- B4.2 Ecological niches

C. Interaction and interdependence

1. Molecules
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
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