About 80% of the human population can taste the chemical phenolthiocarbamide(ptc)" while the otter 20% can't. this characteristic is governed by a single gene with two alleles, a tasting allele and a non-tasting allele. what does this statistic tell us about which allele( tasting or non-tasting) is dominant?

The tasting allele is dominant.

Explanation:

segmentation=endoskeleton=backbone=coelom=tissues

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.