2 Factor Punnett Square Calculator

Mendelian Inheritance Ratios:

\[ \text{Phenotypic Ratio} = 9:3:3:1 \] \[ \text{Genotypic Ratio} = \text{Varies based on parental genotypes} \]

Phenotypic Ratio:

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1. What is a 2 Factor Punnett Square?

A 2 factor Punnett square predicts the genotype and phenotype ratios for offspring from two parents for two different traits. It demonstrates Mendel's principle of independent assortment and shows the classic 9:3:3:1 phenotypic ratio for dihybrid crosses.

2. How Does the Calculator Work?

The calculator generates all possible gametes from each parent's genotype and combines them in a Punnett square:

\[ \text{Gametes} = \text{All combinations of one allele from each gene} \] \[ \text{Offspring genotype} = \text{Combination of gametes from both parents} \]

Where:

Parent genotypes should consist of 4 alleles (e.g., AaBb)
The first letter pair represents one gene
The second letter pair represents the second gene

3. Importance of Punnett Squares

Details: Punnett squares are fundamental tools in genetics for predicting inheritance patterns and understanding probability in Mendelian inheritance.

4. Using the Calculator

Tips: Enter both parent genotypes as 4 letters (e.g., AABb or aaBb). Capital letters represent dominant alleles, lowercase recessive.

5. Frequently Asked Questions (FAQ)

Q1: What does the 9:3:3:1 ratio mean?
A: This classic ratio shows the expected phenotype distribution for two independently assorting traits with complete dominance (9 dominant/dominant, 3 dominant/recessive, 3 recessive/dominant, 1 recessive/recessive).

Q2: When does the 9:3:3:1 ratio not apply?
A: When genes are linked (on the same chromosome) or when there's incomplete dominance, codominance, or epistasis.

Q3: How many boxes are in a 2-factor Punnett square?
A: There are 16 boxes (4 gametes from each parent × 4 gametes from the other parent).

Q4: What's the difference between genotype and phenotype ratio?
A: Genotype ratio shows genetic combinations, phenotype ratio shows observable traits (which depends on dominance relationships).

Q5: Can this calculator handle incomplete dominance?
A: No, this calculator assumes complete dominance for both traits. For incomplete dominance or other inheritance patterns, the phenotypic ratios will differ.