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Course: Middle school biology  > Unit 7

Lesson 5: Reproduction and genetic variation
Science
Middle school biology
Inheritance and variation
Reproduction and genetic variation
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Apply: Punnett squares

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Problem

In a population of pea plants, some plants have yellow seeds and others have green seeds. The gene for seed color has two possible alleles. One allele is for yellow seeds (Y), and the other allele is for green seeds (y).
The Punnett square below models the results of a cross between two pea plants. One of the plants is homozygous for green seeds (yy). The other plant is heterozygous (Yy).
What is the expected ratio of offspring with yellow seeds to offspring with green seeds?
Choose 1 answer: