Download figure 1 - Fort Osage High School

Pedigree Practice
Name: ______________ Block: ____
Examine the pedigree in Figure 1, which traces the dimples trait through three generations of a family.
Blackened symbols represent people with dimples. Circles represent females, and squares represent
males.
FIGURE 1
1. Read the following passage, which describes the family shown in Figure 1. Write the name of each
person below the correct symbol in the pedigree.
Although Jane and Joe Smith have dimples, their daughter, Clarissa, does not. Joe’s father has dimples,
but his mother, and his sister, Grace, do not. Jane’s father, Mr. Renaldo, her brother, Jorge, and her
sister, Emily, do not have dimples, but her mother does.
2. Take another look at Figure 1. A genetic counselor analyzing this pedigree suggests that a person only
needs to have one dominant allele for dimples (D) in order to have dimples. If this is true, what is the
genotype of Person 1 in the third generation of Figure 1?
_________
3. What is the genotype of Person 4 in the second generation of Figure 1? ________
4. What is the genotype of Person 4 in the first generation of Figure 1? ________
5. Construct a pedigree based on the following passage about curly hair. Write the names of each
person on the pedigree next to their correct symbol.
Andy, Penny, and Delbert have curly hair, but their mother, Mrs. Cummins, does not. Mrs. Giordano, Mrs.
Cummin’s sister, has curly hair, but her parents, Mr. & Mrs. Lutz, do not. Deidra and Darlene Giordano
have curly hair, but their sister, Katie, like her father, has straight hair.
Use the following pedigree to answer the questions below.
6. Which of the above numbers would be 7’s aunt?
7. Identify the inheritance pattern found in the pedigree.
_______________
______________
8. Using the letter “R”, write the genotype for individual 1.
9. Using the letter “R”, write the genotype for Individual 2.
10. Using the letter “R”, write the genotype for individual 3.
11. Using the letter “R”, write the genotype for individual 8.
12. Can you be 100% sure about the genotype of individual 4? Why or why not?
13. Complete a Punnett square between #6 and his spouse to show the two possible genotypes that their
offspring might have.
a) What is the percent chance these two parents
will have a child who can roll their tongue? _______
b) How would you write the genotypic ratio for the
F1 offspring? *Remember, a ratio is 1:1 or 1:0 or
1:2:1
14. Hemophilia is a sex-linked recessive trait found on the X-chromosome.
a) Write the genotype of a male that has hemophilia.
(Hint: Use X’s & Y and use “H” for the hemophilia alleles.)
__________
b) Write the genotype of a female who is heterozygous for hemophilia.
___________
15. Do a cross on the Punnett Square to show a cross between Person 5 and 6.
16. From whom did Individual 9 get the gene for hemophilia; 1, 2, 3, or 4?
17. Using H for the “no hemophilia gene” and h for the “hemophilia gene”, write the
genotypes for the following individuals. Be sure to put these letters on an X or a Y, depending on the chromosome
hemophilia is found on. (Hint – Use X’s and Y’)
a) Individual 1
b) Individual 2
c) Individual 6
d) Individual 7
18. Jane has A blood, while her husband Ted has B blood. Their child, Anne has O blood.
a) Draw a pedigree for this family & label each symbol with a name.
b) Write the genotypes for each person using the symbols in your
notes for blood type.
c) Explain how a person with A blood and a person with B blood can
have a child with O blood.
Pedigree