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 (75 percent Pp; 25 percent pp) B. 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) C. 50 percent chance of a polka-dot tail and 50 percent chance of a solid colored tail (50 percent PP; 50 percent pp) D. 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)

Answer 1

First, we consider the parents:

Phenotypes: Polka dots
Genotypes: Pp

Using a punnet square,

        P       p
P    PP     Pp

p    Pp      pp

Therefore, out of four, the phenotypes and genotypes of the offspring will be as follows:

Phenotypes: 3 with polka dots (75%) and 1 with solid (25%)
Genotypes: 1 dominant homozygous (25%), 1 recessive homozygous (25%) and two dominant heterozygous (50%)

The answer is option D.