Both carbon dioxide and water are pure substances. how are they similar to each other?
a. both substances have a set ratio of atoms that cannot be separated.
b. both substances have a set ratio of atoms that can be separated.
c. both substances have the same physical and chemical properties.
d. both substances have the same physical properties, but different chemical properties.

The answer is a.

Pure substances, by definition, are made of only one kind of atom/molecule, and cannot be broken down. Thus, their atoms cannot be separated.

b is incorrect because the atoms can't be separated.
c and d are incorrect because carbon dioxide and water do not have similar physical properties.

The answer would be c, white eyes are homozygous recessive. in the early 1900s, morgan conducted several experiments with vinegar  flies (drosophila). one  sample revealed an anomaly: a  white-eyed, single male fly. he attempted to breed this fly with the typical red-eyed females. the offspring were all red-eyed. using flies from this new generation (brother-sister pairs)  produced some red-eyed and a few white-eyed flies. the white-eyed were all male. in later experiments, he was able to produce white-eyed females. this proved that white eyes are not lethal to either sex (ruling out a and b). since the percentage of white eyes to red eyes is so low, white eyes are not a dominant trait. it would be a recessive trait.