8th Grade Science
Name ____________________________
Punnett Square Practice
1. In a flower, purple (P) is dominant and white (p) is recessive. Complete the Punnett square for a PP
father and Pp mother and answer the following questions
What color(s) are the parents? __________________________________________________
What color(s) are the offspring? _________________________________________________
What percent of the children will carry the recessive gene? __________
2. In a certain type of seed, yellow (Y) is dominant and green (y) is recessive. Complete the Punnett
square for a Yy father and Yy mother and answer the following questions
What color(s) are the parents? __________________________________________________
What color(s) are the offspring? _________________________________________________
What percent of the offspring can be green? ________________ yellow? _________________
3. For a certain type of seed round (R) is dominant and wrinkled (r) is recessive. Complete the Punnett
square for a Rr father and rr mother and answer the following questions
What color(s) are the parents? _________________________________________________
What color(s) are the offspring? ________________________________________________
What percent of the offspring will have the dominant gene? ______________
4. If both parents are homozygous dominant, can they have offspring with the recessive trait? Explain
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5. Can an organism ever be heterozygous recessive? Explain __________________________________
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