1. Punnet Square Practice
Lesson 5
Punnet Square Practice

2. E e Father Practice Problem 1 - Part 1 Earlobes have two forms.
Unattached earlobes are dominant (E).
Attached earlobes are recessive (e).
The father is heterozygous.
Question: What is his genotype?
Answer: His genotype is Ee because he is heterozygous. E
Father e

3. e e E e Mother Mother Father Practice Problem 1 - Part 2
Earlobes have two forms.
Unattached earlobes are dominant (E).
Attached earlobes are recessive (e).
Question: If the mother has attached earlobes, what is her genotype?
Mother
Mother e e E
Father
Answer: Her genotype must be ee because attached earlobes are recessive. e

4. e e E E e E e e e e e e Mother Father Practice Problem 1 - Part 3
So the father is heterozygous (Ee)
The mother is homozygous dominant (ee).
Question: What are the chances that their offspring will have attached earlobes?
Mother e e
Answer: There is a 50% chance because there are two boxes with the ee genotype. E
Father E e E e e e e e e

5. D D d D d D d d D d D d Mother Father Practice Problem 2
Dimples are a dominant trait (D)
Not having dimples is the recessive trait (d).
A mother is homozygous dominant (DD)
The father is homozygous recessive (dd).
Question: What are the chances they have children with dimples.
Mother D D
Answer: 100% will have dimples because all possible children carry at least one dominant allele. d
Father D d D d d D d D d

6. Practice Problem 3
Freckles (F) are a dominant trait.
Not having freckles is a recessive trait (f).
Question: If mother is a heterozygous and a father is a homozygous recessive, what are the chances that their offspring will have freckles?
Mother F f
Answer: There is a 50% chance that their offspring will have freckles because the dominant allele appears half the time. f F f f f f F f f f