Download Eye color

Skin tone
Acne
Dark
Medium
SS
Ss
Light
(pink)
ss
Light
Light
Heavy
AA
Aa
aa
Eye color
Dark eyes are dominant over light eyes. To determine the color of your child’s eyes, assume
there are two gene pairs involved, one which codes for depositing pigment in the back of the
iris, and one which codes for depositing pigment in the front of the iris. Determine the
genotype of the first pair (AA, Aa, aa) and then the second pair (BB, Bb, bb). Each parent
donates one “A” and one “B” gene.
AABB
AABb
AaBB
AaBb
Intense Brown
Intense Brown
Brown with green flakes
Brown
AAbb
Aabb
aaBB
aaBb
aabb
Brown
Gray-blue
Green
Dark Blue
light blue
Hair Color
Dark hair is dominant over light hair. To determine the color of your child’s hair, assume there
are two gene pairs involved. There are probably more. Flip your coin to determine the
genotype of the first pair of genes: (AA, Aa, aa). Now flip your coin again to determine the
genotype of the second pair of genes (BB, Bb, bb). Each parent donates one of each type of
genes to the offspring.
AABB
AABb
AAbb
AaBB
Aabb
Black
Black
Red
Brown
Light Brown
AaBb
aaBB
aaBb
aabb
Brown
Sandy Blond (mixed with brown)
Regular Blond
Pale yellow Blond
Parent’s Name
Name of the Child
Sex of the child
Description of Trait
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Phenotype
Genotype
In the space provided below, draw a picture of your child’s face using the characteristics listed
above.
Analysis and Conclusions
1. What percent chance did you and your partner have of “producing” a male offspring? Explain your answer.
2. Would you expect the other pairs of students in your class to have an offspring similar to yours? Explain your
answer.
3. If a woman who is homozygous for almond-shaped eyes (AA) marries a man who is heterozygous for
almond-shaped eyes (Aa), what are the possible genotypes and phenotypes of their children?
a. Genotypes
b. Phenotypes
4. What genotype causes a child to have wavy hair?
5. What phenotypes are possible for “position of eyebrows”?
6. Which traits in the investigation shows incomplete dominance (blending of traits)?
7. How is it possible for a child to show a trait when neither of the parents showed the same trait? For example,
how is it possible for a child to have a connected eyebrow, when neither of the parents had a connected
eyebrow?
8. Could two parents who both have curly hair have a child with straight hair? Explain why or why not?
9. Could two parents who both have a round shaped face have a child with a square shaped face? Explain why
or why not?
10. What is the genotype of a woman?
11. What is the genotype of a man?
12. Why do the fathers determine the sex of their offspring and not the mothers?
13. Identify 3 traits your child is heterozygous for?
14. Name two traits that it requires two different genes to determine the characteristic?