⦁ In what stage of an animal’s life cycle do most cells differentiate?

Animals and plants produced by sexual reproduction begin life as a single cell, a fertilised egg or zygote . These cells must divide by mitosis to produce a multicellular organism.

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.