Which of the earth's systems makes up all the living organisms found on earth?
a. upper mantleb. asthenospherec. lithosphered. crust

Is this a question? i'm confused

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. 

It's important for a woman to know she is pregnant within the first trimester so she won't consume any alcohol or cigarettes which will harm the baby.

The answer is:   [a]:   "heart disease, cancer, and stroke" .