A - Unity and Diversity
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)
B4.1 Adaptation to environment
B4.2 Ecological niches
C - Interaction and Interdependence
D - Continuity and Change
View a summary cheatsheet for B2.3 Cell specialization
B2.3.1 Production of unspecialized cells following fertilization and their development
B2.3.2 Properties of stem cells
B2.3.3 Location and function of stem cell niches in adult humans
B2.3.4 Differences between totipotent, pluripotent and multipotent stem cells
B2.3.5 Cell size as an aspect of specialization
B2.3.6 Surface area-to-volume ratios and constraints on cell size
B2.3.7 Adaptations to increase surface area-to-volume ratios of cells (HL)
B2.3.8 Adaptations of type I and type II pneumocytes in alveoli (HL)
B2.3.9 Adaptations of cardiac muscle cells and striated muscle fibres (HL)
B2.3.10 Adaptations of sperm and egg cells (HL)
