(3) Calyx Explanation: A flower has calyx, corolla, androecium and gynoecium. Calms and corolla are accessory organs, while androecium and gynoecium are reproductive organs. Photosynthetic activity is found in the calyx, green shoulder, pericarp, and locular parenchyma. It suggests that all of these tissues have significant roles in CO2 scavenging and the provision of carbon assimilates.