Punnett Squares and Predicting Inheritance
Predicting traits
What a Punnett square does
A Punnett square is a simple chart used to predict the possible genotypes of offspring from a genetic cross.
How to use a Punnett square
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1
Step 1: Write one parent's possible alleles across the top.
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2
Step 2: Write the other parent's possible alleles down the side.
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3
Step 3: Combine the alleles in each box.
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4
Step 4: Count the possible genotype outcomes.
Remember
Punnett squares show probabilities, not guarantees. Real offspring outcomes can vary.
Example cross
| Parent 1 | Parent 2 | Possible offspring |
|---|---|---|
| Aa | Aa | AA, Aa, aa |
| AA | aa | All Aa |
| Aa | aa | Aa, aa |
What is a Punnett square used for?
A Punnett square is a tool for predicting allele combinations in offspring.
Correct answer: Predicting possible inheritance outcomes
What does a Punnett square show: certainty or probability?
It shows likely outcomes, not guaranteed results.
Correct answer: Probability
If one parent is and the other is , what are all the offspring genotypes?
Each offspring gets one and one , so all are .
Correct answer: All
What do the boxes in a Punnett square represent?
Each box shows one possible allele combination in a child or offspring.
Correct answer: Possible offspring genotype combinations