Name ______________________________________________ Period _______________
Use the information in section 11.2 to answer the questions below.
1. What is the Principle of Independent Assortment? What does this mean in your own words?
2. What is the difference between a monohybrid cross and a dihybrid cross?
3. You have mastered monohybrid crosses. Now, you will be challenged to create a dihybrid
cross. Fill in the missing genotypes in the dihybrid Punnett Square below.
This is a cross between a round yellow plant (RRYY) and a wrinkled green plant (rryy)
RY
ry
RrYy
ry
ry
RY
RY
RY
RrYy
RrYy
RrYy
RrYy
ry
What are the possible genotypes and phenotypes?
RrYy
Name ______________________________________________ Period _______________
4. What results would you get if you crossed two offspring from the previous cross? Create a
dihybrid Punnett Square.
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How many plants are round green? Round yellow?
Wrinkled yellow?
Wrinkled green?
What is the phenotypic ratio for this cross?
______ : ______ : _______ : _______
5. Here’s a challenge! What would the results be for a cross between a homozygous dominant
tall and heterozygous yellow seeded pea plant, and a heterozygous tall and green-seeded pea
plant? (Hint: First, figure out the parent’s alleles. Then, determine all possible allele
combinations for each parent, and then you can set up your dihybrid Punnett Square.)
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What are the possible genotypes and corresponding phenotypes?
____