Dihybrid Crosses Practice Problems
Two sets of genes on different chromosomes are responsible for the coat color in an animal X. Gene B codes for the brown color and gene G for grey. Beige-colored coat results when these genes are in heterozygous condition and in case both the genes are recessive, the coat color is white. Suppose, a male of X is mated with a female of X, both having a beige coat, what fraction of the progeny do you expect to have white coat color (albino, unpigmented)?
A total of 500 offspring were produced when 100 male cats with black coats and long fur were mated with 100 female cats with the same phenotype. Out of these 500, 281 had black coats and long fur, 93 had black coats and short fur, 92 had brown coats and long fur, and 32 had brown coats and short fur. If both genes are present on different chromosomes, which one do you believe is the recessive allele in each trait studied?
In humans, brown eyes are a dominant trait over blue eyes. If a brown-eyed heterozygous male marries a blue-eyed female, what is the probability of producing blue-eyed offspring?
A dominant allele (I) inhibits kernel color in maize (corn) plants, whereas a recessive allele (i) allows color at one locus. Purple kernel color is caused by the dominant allele (P), whereas red kernel color is caused by the recessive allele (p) at a different locus. What will the phenotypic ratio of the offspring be if two maize plants that are heterozygous at two loci are crossed?