Name ___________________________________________
Period _______
Date _______________
PUNNETT SQUARES WORKSHEET 7
1.
2.
3.
Red-Green color blindness is an X-linked recessive disorder. Since normal vision is dominant, it is
typically represented as XB. Color blindness is shown as Xb. If a normal female wants to have
children with a color-blind male, what is the probability of having a son who is color blind? A
daughter who is color blind? A daughter who is a carrier? In addition, determine the genotypes of
the two parents.
Genotype of Mother
_______________________
Genotype of Father
_______________________
Color-blind Son
_______________________
Color-blind Daughter
_______________________
Carrier Daughter
_______________________
If a color-blind female wants to have children with a normal male, what is the probability one of
their sons could be color blind? (Only the sons should be factored into this calculation…) One of
their daughters color blind? One of their daughters a carrier? In addition, determine the
genotypes of the two parents.
Genotype of Mother
_______________________
Genotype of Father
_______________________
Color-blind Son
_______________________
Color-blind Daughter
_______________________
Carrier Daughter
______________________
If a female carrier wants to have children with a color-blind male, what is the probability of one of
their sons could be color blind? One of their daughters color blind? One of their daughters a
carrier? In addition, determine the genotypes of the two parents.
Genotype of Mother
_______________________
Genotype of Father
_______________________
Color-blind Son
_______________________
Color-blind Daughter
_______________________
Carrier Daughter
______________________
Name ___________________________________________
Period _______
Date _______________
4. Reduced fertility in men is often a result of a microdeletion of a gene on the y-chromosome. If a ychromosome contains this change, it is noted as Yf. Normal fertility could be shown as YF, or simply
Y. If a female wants to have children with a male suffering from reduced fertility, what is the
probability one of their sons could have reduced fertility? One of their daughters reduced fertility?
In addition, determine the genotypes of the two parents.
Genotype of Mother
_______________________
Genotype of Father
_______________________
Reduced Fertility Son
_______________________
Reduced Fertility Daughter
5.
_________________
A husband and wife are interested in having a child. They would really like a boy with Type O blood
and normal vision (not red-green color blind). It is known that blood type shows a codominant
inheritance pattern for the A and B alleles, with the O allele being recessive. Red-green color
blindness is an X-linked recessive disorder. If the husband is heterozygous for Type B blood and has
normal vision, and the wife has Type O blood and is a carrier for color-blindness, determine the
following:

Complete the dihybrid cross assuming both traits follow the law of independent assortment

Phenotypic ratio of all possible offspring

Probability of a son with Type O blood and normal vision
___________________________________
Husband
X
___________________________________
Wife
Phenotypic Ratio
____________________
____________________
____________________
Son w/ Type O Blood,
Normal vision
_____________________