In Snapdragons, petal color is inherited through incomplete dominance with the possible colors being red, white, and pink. What would be the chance of getting a pink flower if you cross a red flower with a pink flower?

answer; a male inherits only one allele of the x-linked gene controlling hair color;

oak trees? ? what was listed

b.have there own function.

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.