If C is dominant to c, what fraction of offspring will show the dominant phenotype when two heterozygous parents are crossed?
A)0/4
B)1/4
C)2/4
D)3/4
E)4/4

Question

If C is dominant to c, what fraction of offspring will show the dominant phenotype when two heterozygous parents are crossed? ​
A)0/4
B)1/4
C)2/4
D)3/4
E)4/4

Quizplus · Accepted Answer

If C is dominant to c, that means that if an individual inherits one copy of the dominant C allele and one copy of the recessive c allele, they will exhibit the dominant phenotype. When two heterozygous parents are crossed (Cc x Cc), they each have one copy of the dominant C allele and one copy of the recessive c allele. The Punnett square for this cross would produce offspring with the genotypes CC, Cc, cC, and cc. Out of these four possible genotypes, three of them (CC, Cc, and cC) would exhibit the dominant phenotype, while only one (cc) would exhibit the recessive phenotype. Therefore, the fraction of offspring that would show the dominant phenotype is 3/4 or 75%.

If C Is Dominant to C, What Fraction of Offspring