Punnett Squares Practice

Practice Punnett squares & master genetics! Predict offspring traits and probabilities.

Complete the Punnett Square and answer the questions that follow. In rabbits, black fur is dominant to white fur. If you cross a BB male with a Bb female, what are the possibly genotypes and phenotypes of the offspring? Punnett Square B B B BB BB b Bb Bb What is the percent chance an offspring rabbit will be black? 0% 25% 50% 100% What is the percent chance an offspring rabbit will be white? 0% 25% 50% 75% Create a Punnett Square and answer the questions that follow. In cabbage butterflies, green wings are dominant to white wings. If a Gg butterfly is crossed with a gg butterfly, what are the possible genotypes and phenotypes of the offspring and the percent chance for each. Punnett Square G g g Gg gg g Gg gg What is the percent chance the offspring will have white wings? 25% 50% 75% 100% What is the percent chance the offspring will have yellow wings? 0% 25% 50% 75% A heterozygous purple-flowered plant (Pp) is crossed with another heterozygous purple-flowered (Pp) plant. Fill in the Punnett Square below by entering the parent genotypes on the top and left sides and the offspring in the middle. Punnett Square P p P PP Pp p Pp pp Based on the Punnett square above, what would be the genotypic ratio of the offspring? 1 PP : 1 Pp : 2 pp 1 PP : 2 Pp : 1 pp 2 PP : 1 Pp : 1 pp 3 PP : 1 Pp : 0 pp Based on the Punnett square above, what would be the phenotypic ratio of the offspring? 3 purple : 1 white 4 purple : 0 white 2 purple : 2 white 1 purple : 3 white In pea plants, yellow seeds (Y) are dominant to green (y). Two pea plants are crossed, and 50% of their offspring have yellow seeds while 50% have green seeds. Which of the following could be the genotypes of the parents? (Hint: Do a Punnett Square for each choice and see which answer gives a 50 ratio of yellow to green.) YY x yy Yy x Yy YY x Yy Yy x yy In mice black eyes (B) are dominant to red eyes ( ). Two mice mate, and 75% of their offspring have black eyes while 25% have red eyes. Which of the following could be the genotypes of the parents? (Hint: Do a Punnett Square for each choice and see which answer gives a 75% ratio of black to red eyes.) BB x BB BB x Bb Bb x Bb Bb x bb