Professor Marcus is studying gene expression in the liver cells of a mouse. She observes that when a
steroid hormone enters the liver cells, the cells begin producing a wide variety of new proteins.
Which of the following statements is the MOST USEFUL to include in an explanation of this observation?
O A. The steroid hormone contains several genes.
O
B. A transcription factor activates a single gene that produces several proteins.
OC. A transcription factor activates many genes at the same time.
о
D. The steroid hormone mimics the function of several mRNA molecules.

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. 

The answer is b, as with an inference you make a statement with no evidence