Arecessive allele a. occurs as a regulatory gene only b. needs to be present on only one chromosome to be expressed c. is never expressed d. needs to be present on both chromosomes to be expressed

D: needs to be present on both chromosomes to be expressed

Why: Because if there was a dominant trait present, then the dominant trait would overpower the recessive trait regardless of the matter.

the answer is b)3/8x+1

sex cells are usually half's then they find another half and make a fertilize egg