How a difference in the sequence of nucleotides in a gene could result in one of these boys being albino and the other boy having normal skin and hair color?

A difference in the sequence of nucleotides in a gene can lead to variations in the proteins produced, which may affect melanin production in individuals. For instance, a mutation in the gene responsible for melanin synthesis could result in reduced or absent melanin, causing albinism in one boy. In contrast, the other boy may have the normal sequence, leading to typical pigmentation. Thus, even a single nucleotide change can significantly impact phenotype by altering gene function.