In mice, black coat color (B) is dominant over brown (b), and a solid pattern (S) is dominant over white spotted (s). Color and spotting are controlled by genes that assort independently. A homozygous black, spotted mouse is crossed with a homozygous brown, solid mouse. All the F1 generation are black and solid. A testcross is then carried out on the F1 mice.
Give the genotypes of the parents and the F1 mice, then give the genotypes and phenotypes, along with their expected ratios, of the progeny expected from the testcross.