1. Punnett Squares Punnett Squares Z Z Z Z Z z z z z z z
Method used to calculate the probable offspring genotypes
Steps to creating Punnett Squares:
Get the parent’s genotypes Ex: ZZ, Zz, zz
Draw a Punnett Square
Put the parent’s genotypes on the top and the left side
Drop the alleles down from the top
Slide the alleles over from the left side
Each box is worth 25%
z z Z Z Z z z Z Z z z

2. Punnett Squares Punnett Squares Aa 50% AA 50% Aa Possible Phenotypes:
Punnett Example:
Father Genotype: Aa
Mother Genotype: AA
Possible Genotypes:
50% AA
50% Aa Possible Phenotypes:
100% Dominant Trait

3. Punnett Squares Punnett Squares Punnett Example:
Tongue curling is a dominant trait:
Dominant allele = C Recessive allele = c
Homozygous dominant = ______
Homozygous recessive = ______
Heterozygous = ______
People heterozygous for tongue curling can curl their tongue. T / F
A homozygous recessive mom for tongue curling and a heterozygous father want to know if their children will be able to curl their tongues. Calculate the genotype and phenotype percentages for the offspring.

4. Punnett Square Examples
Punnett Squares
Punnett Square Examples
Punnett Example:
Brown hair is dominant over blonde hair:
Dominant allele = B Recessive allele = b
Homozygous dominant = ______
Homozygous recessive = ______
Heterozygous = ______
Genotypes:
Phenotypes:

5. Punnett Square Examples
Punnett Squares
Punnett Square Examples
Punnett Example:
Purple flowers are dominant over white flowers
Dominant allele = P Recessive allele = p
Homozygous dominant = ______
Homozygous recessive = ______
Heterozygous = ______
Genotypes:
Phenotypes:

6. Punnett Square Examples
Punnett Example:
Round flowers is dominant over pointed flowers
Dominant allele = R Recessive allele = r
Homozygous dominant = ______
Homozygous recessive = ______
Heterozygous = ______
Genotypes:
Phenotypes:

7. Punnett Square Examples
Punnett Example:
Smooth corn kernels are dominant over wrinkled
Dominant allele = S Recessive allele = s
Homozygous dominant = ______
Homozygous recessive = ______
Heterozygous = ______
Genotypes:
Phenotypes: