Name: __________________________
Worksheet – Punnett Square Review
Date: __________/HW#: ____
Mr. Jensen/Period: ____
Punnett Square Review
Complete the Punnett Squares below and list the Genotype and
Phenotype probabilities as fractions and percentages.
Let’s work with Pea Plants like Mendel did. We will look at the possibilities of pod
color. Green is the dominant pod color and yellow is the recessive pod color.
Pick letters:
[Green:
G
]
[Yellow:
g
]
Try these combinations…
G
G
G
G
G
G
G
g
G
g
g
Genotypes
?
/4
%
Phenotypes
?
Genotypes
/4
%
Phenotype
G
g
Genotypes
G
g
g
g
g
g
Phenotypes
/4
%
Genotypes
Phenotype
/4
g
g
?
?
%
Phenotype
G
Genotypes
G
?
/4
%
Genotypes
Phenotype
g
?
/4
%
Now try to do the same thing for right- or left-handedness. Righthandedness is dominant [R] and left-handedness is recessive [r].
Genotypes
?
/4
%
Phenotypes
Genotypes
Genotypes
?
/4
%
Phenotype
?
/4
%
Phenotypes
Genotypes
Genotypes
?
/4
%
/4
%
Phenotype
?
/4
%
Phenotype
Genotypes
?
Phenotype
Mr. Jensen is left-handed but both of his parents are right-handed. Look at the Punnett
squares that you completed above and determine which one has two right-handed parents
having left-handed offspring.
1. What are the genotypes of Mr. Jensen’s parents?
Mother’s Genotype:
2.
Father’s Genotype:
Using the same Punnett Square, what is the probability of these parents having
left-handed offspring?
%