If two fruit flies, heterozygous for a gene that codes for eye color , were bred together and had 200 offspring , about how many would have the dominant phenotype

75%

Explanation:

Assuming that eye color follows mendellian inheritance, two heterozygous parents would breed as follows:

Ee x Ee

Punnett sqaure

     E     e

E   EE    Ee

e   Ee    ee

All organisms possessing allele E will express dominant phenotype.