3. For what purpose are the points where Earth's axis of rotation intersects Earth's surface used?

The points at which Earth's axis of rotation intersects Earth's surface are used as reference points for defining direction. These points are the geographic North Pole and South Pole. Halfway between the poles, a circle called the equator divides Earth into the North and Southern Hemispheres.

Explanation:

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.