What is needed for photosynthesis to occur and where does it come from

Sunlight is primarily needed for photosynthesis to occur.

Explanation: Plants need the sunlight for food production. They convert the light energy from the sun into chemical energy which is the used to fuel their activities.

answer: "circumcision is a common procedure in which the skin covering the tip of the penis is surgically removed."

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.