Amale and female bison that are both heterozygous for normal skin pigmentation (aa) produce an albino offspring (aa). which of mendel's principles explain(s) why the offspring is albino? a. dominance only c. dominance and segregation b. independent assortment only d. segregation only

It is not going to be dominance - the offspring in question have two recessive alleles (aa), neither of which is dominant to the other. So options A and C are both out the window.

Of the remaining two possibilities, segregation basically just states that each offspring has two alleles for each gene, one from each parent. Which doesn't go a long way telling you why this particular offspring is albino.

By contrast, independent assortment is much more relevant. It says that either chromosome from each parent has an equal chance of ending up in any particular baby. So it implies that each parent will pass on its recessive albino allele (a) to some of its offspring. And some of the offspring will independently get an a allele from each parent and be aa for albino.

Hope I helped. :)