A - Unity and Diversity
B - Form and Function
C - Interaction and Interdependence
C1.1 Enzymes and metabolism
C1.2 Cell respiration
C1.3 Photosynthesis
C2.1 Chemical signalling (HL)
C2.2 Neural signalling
C3.1 Integration of body systems
C3.2 Defense against disease
C4.1 Populations and communities
C4.2 Transfer of energy and matter
D - Continuity and Change
View a summary cheatsheet for C4.2 Transfer of energy and matter
C4.2.1 Ecosystems
C4.2.2 Sunlight
C4.2.3 Flow of chemical energy through food chains
C4.2.4 Construction of food chains and food webs
C4.2.5 Supply of energy to decomposers
C4.2.6 Autotrophs
C4.2.7 Use of light as the external energy source
C4.2.8 Heterotrophs
C4.2.9 Release of energy in both autotrophs and heterotrophs
C4.2.10 Classification of organisms into trophic levels
C4.2.11 Construction of energy pyramids
C4.2.12 Reductions in energy availability at each successive stage in food chains
C4.2.13 Heat loss to the environment in both autotrophs and heterotrophs
C4.2.14 Restrictions on the number of trophic levels in ecosystems
C4.2.15 Primary production as accumulation of carbon compounds in biomass by autotrophs
C4.2.16 Secondary production as accumulation of carbon compounds in biomass by heterotrophs
C4.2.17 Constructing carbon cycle diagrams
C4.2.18 Ecosystems as carbon sinks and carbon sources
C4.2.19 Release of carbon dioxide into the atmosphere during combustion
C4.2.20 Analysis of the Keeling Curve in terms of photosynthesis, respiration and combustion
C4.2.21 Dependence of aerobic respiration on atmospheric oxygen produced by photosynthesis
C4.2.22 Recycling of all chemical elements required by living organisms in ecosystems