A - Unity and Diversity
A1.1 Water
A1.2 Nucleic acids
A2.1 Origins of cells (HL)
A2.2 Cell structure
A2.3 Viruses (HL)
A3.1 Diversity of organisms
A3.2 Classification and cladistics (HL)
A4.1 Evolution and speciation
A4.2 Conservation of biodiversity
B - Form and Function
C - Interaction and Interdependence
D - Continuity and Change
View a summary cheatsheet for A1.1 Water
A1.1.1 Water as the medium for life
A1.1.2 Hydrogen bonds as a consequence of the polar covalent bonds within water molecules
A1.1.3 Cohesion of water molecules due to hydrogen bonding and consequences for organisms
A1.1.4 Adhesion of water to materials that are polar or charged and impacts for organisms
A1.1.5 Solvent properties of water as a medium for metabolism and transport
A1.1.6 Physical properties of water and the consequences for animals in aquatic habitats
A1.1.7 Extraplanetary origin of water on Earth and reasons for its retention (HL only)
A1.1.8 Relationship between the search for extraterrestrial life and the presence of water (HL only)
