★ What would happen if there were no photosynthesis?

If there was no photosynthesis ,there would be no oxygen produced by the trees which would cause the world to eventually be left with carbon dioxide as all the oxygen will be used up in the end which would lead to and increase in the degee of global warning and all living things will eventually die.
Food cycle would also be disrupted as all living things directly/indirectly depends on plants for food as plants are the starters of food chains as they produce glucose through photosynthesis.