Question

Suppose that a dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail. If two heterozygous individuals with polka-dot tails mate, what's the probability of the phenotype and genotype combinations of the offspring? A. 75 percent chance of a polka-dot tail and 25 percent chance of a solid colored tail (25 percent PP; 50 percent Pp; 25 percent pp) B. 75 percent chance of a polka-dot tail and 25 percent chance of a solid colored tail (75 percent Pp; 25 percent pp) C. 25 percent chance of a polka-dot tail and 75 percent chance of a solid colored tail (25 percent PP; 50 percent Pp; 25 percent pp) D. 50 percent chance of a polka-dot tail and 50 percent chance of a solid colored tail (50 percent PP; 50 percent pp)

Answer 1

The answer is A. When doing crosses with Punnett squares, two heterozygous individuals will produce one dominant, two heterozygous, and one recessive. The genotypic ratio would be 25% PP 50% Pp and 25% pp. The phenotypic ratio would be 75% polka-dot tail and 25% solid-colored tail. Since Pp has a dominant in it, it overshadows the recessive so 25% and 50% added would be 75%.