2. why can you say that males determine the sex of their children?

since males have two x chromosomes, whichever one is passed along to their offspring will determine the sex.

male chromosomes are inherited preferentially over female chromosomes.

males will either contribute an x or a y chromosome, whereas females will always contribute an x chromosome.

y chromosomes are dominant; x chromosomes are recessive.

all of the above.

Male will either contribute an X or Y chromosome

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.