Which would be the producer in a food chain? a. fish b. bird c. insect d. plant

Plant is a producer in food chain

D. Plant

This is because plants create food foe other animals.

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.

there's the proffessional site that will you.