1) density-dependent inhibition is explained by which of the following? a) as cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce growth factors. 1) b) as cells become more numerous, the cell surface proteins of adjacent cells bind to each other and send signals that inhibit cell division. c) as cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. d) as cells become more numerous, the level of waste products increases, eventually slowing down metabolism.

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.