Holt Modern Biology 1st Edition by John Postlethwait ,Janet Hopson

Exercise 45

Analyzing Data In Drosophila the genes for body color and wing length are on the same chromosome. Gray body ( G ) is dominant to black body ( g ), and long wings ( L ) are dominant to short wings ( l ). Assume that both dominant alleles are on the same chromosome. Draw a Punnett square representing the cross G gLl × GgLl. Write the phenotypic and genotypic ratios that would be expected among the offspring, assuming that crossing-over does not occur.