Dihybrid Genetic Crossing Questions/ Quiz

Application of Law of Segregation and Law of Independent Assortment

 

Dihybrid Crossing Examples

1.       In a dihybrid cross, if you cross two pea plants, one with yellow round seeds (YR) and the other with green wrinkled seeds (yr), what are the possible genotypes of their offspring?

 

2.        A heterozygous individual for two traits (AaBb) is crossed with another heterozygous individual (AaBb). What is the expected phenotypic ratio of their offspring?

 

3.         In mice, black fur (B) is dominant to white fur (b), and long tails (L) are dominant to short tails (l). If you cross a heterozygous black-furred, long-tailed mouse with a white-furred, short-tailed mouse, what are the expected phenotypes of their offspring?

 

4.      In fruit flies, eye color is determined by the B (brown) and b (red) alleles, while wing shape is determined by the W (wild-type) and w (vestigial) alleles. If a BBWW fruit fly is crossed with a bbww fruit fly, what will be the genotypes of their F1 generation?

 

5.       In corn plants, tall (T) is dominant to short (t), and yellow (Y) kernels are dominant to green (y) kernels. If you cross two corn plants, one tall and heterozygous for kernel color (TtYy) and the other short with yellow kernels (ttyy), what are the possible genotypes and phenotypes of their offspring?

 

6.    In guinea pigs, black fur (B) is dominant to white fur (b), and rough coat (R) is dominant to smooth coat (r). If you cross a heterozygous black-furred, rough-coated guinea pig with a white-furred, smooth-coated guinea pig, what are the expected genotypic and phenotypic ratios of their offspring?

 

7.      In rabbits, black fur (B) is dominant to brown fur (b), and floppy ears (E) are dominant to upright ears (e). If you cross a heterozygous black-furred, floppy-eared rabbit with a brown-furred, upright-eared rabbit, what are the possible genotypes and phenotypes of their offspring?

 

8.        In sweet peas, purple flowers (P) are dominant to white flowers (p), and inflated pods (I) are dominant to constricted pods (i). If you cross a homozygous purple-flowered plant with inflated pods (PPII) with a white-flowered plant with constricted pods (ppii), what will be the genotype of their F1 generation?

 

9.         In Drosophila (fruit flies), body color (C) is dominant to pale body color (c), and eye shape (E) is dominant to round eye shape (e). If you cross a heterozygous body color fly with pale body color and round eye shape (CcEe) with a fly homozygous for pale body color and round eye shape (ccee), what are the possible genotypes and phenotypes of their offspring?

 

10.       In dogs, coat color is determined by two genes: B (black) and W (white). Black (BB or Bw) is dominant to white (ww). If a black-coated, heterozygous dog (Bw) is crossed with a white-coated dog (ww), what are the potential coat color genotypes of their puppies?