You have round polka dotted round is dominant and you cross

You have round polka dotted (round is dominant), and you cross this with a round solid patterned (solid is recessive) mouse. Show all possibilities with the Punnett squares of possible offspring.

Solution

Let say one of the parent is round polka dotted mouse - RR and other parent is round solid patterned rr.

Round is dominant and solid is recessive.

F1 cross RR x rr

All progenies will have genotype of Rr and their phenotype will be round pola dotted.

In F2 cross

Rr x Rr

R r

R RR Rr   

r Rr rr So RR and Rr both have round polka dots. Hence, 75 % of population has round polka dots and 25 % of population of progeny will have round solid pattern.

Genotypic ratio 1:2:1 and phenotypic ratio is 3:1