Which structure did you see in the eukaryotic cells that is absent in the prokaryotes?

Eukaryotic cells contain membrane-bound organelles such as nucleus while it is absent in prokaryotic cells. The membrane-bound organelles present in eukaryotic cells is an organized and specialized structure which include the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, vacuoles, lysosomes, mitochondria, and, in plants, chloroplasts. All of these organelles perform different functions within the eukaryotic cells.

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.

d. groundwater flows through the subsoil and deposits minerals.