Light Harvesting, Dependant and Independant Stages with Absorption and Action Spectrum. CCEA NI Specification. Photosynthesis shown as a summary through its stages and biochemistry including light harvesting in antenna complex, dependant stage in chloroplasts in z-scheme and independant stage in stroma. Additional notes on absorption spectrum of light waves absorption of different pigments and action spectrum showing the rate of photosynthesis at different wavelengths.