In a snail, an autosomal allele causing a banded shell (b) is recessive to the allele for unbanded shell (B). Genes at a different locus on the same chromosome determine the background color of the shell; here, yellow (y) is recessive to brown (Y). The genes for shell banding and background color have a recombination frequency of 0.25. A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a testcross). What proportion of progeny will be banded and brown