In a plant, red colour of fruit is dominant over yellow colour. When these two pure lines are crossed, the probability of producing F2 homozygous plants with red fruits, heterozygous plants with red fruits, and plants with yellow colored fruits respectively is
1/4, 1/2 and ¼
The F2 genotypic ratio of this monohybrid cross is 1:2:1. As the Punnett Square explains, out of the 4 combinations, the probability of homozygous dominant character is 14, that of heterozygous dominant character is 24=12 , and homozygous recessive character is 14 .