Essential Genetics 6th Edition by Daniel Hartl

Exercise 14

In plants, certain mutant genes are known that affect the ability of gametes to participate in fertilization. Suppose that an allele A is such a mutation, and that pollen cells bearing the A allele are only half as likely to survive and participate in fertilization as pollen cells bearing the a allele. What is the expected ratio of AA : Aa : aa plants in the
generation of a monohybrid cross? (Hint: Use a Punnett square.)