1. Do Now 2.19 Objective: Use a pedigree to trace the inheritance of genetic traits through a family and determine how they are inherited. Task: Copy the key into “pedigree basics” on the notes handout

2. Tracing Albinism
Parents A & B do not have albinism, yet they produced child E that does. What does that tell us about the genotype of the parents? C D E G A B
Parents C & D do not have albinism, yet they produced child that does. What does that tell us about their genotypes?
Albinism: recessive trait (aa)

3. Your turn - Dwarfism C D E F G A B
Hint: Look at E, F, and their offspring to determine what’s going on here!

4. Pedigrees and X-linked traits
DO Now:
Pattern baldness (example = Mr. T) is caused by a recessive allele carried on the X chromosome (Xo = baldness, X+ = normal)
Construct a Punnett square that shows a cross between an unaffected man and a woman who is a carrier.
Question: should a man with pattern baldness blame his father, mother, or both?

5. Something’s a Little different here

6. Make a pedigree! (Classwork)
Jack and Jill are not colorblind.
They have 4 daughters, April, May, June, and August. None of their daughters are colorblind.
April marries Larry (who is not colorblind), and they have 3 sons, Larry jr., Mo, and Curly. Mo and Curly are colorblind.
May does not have any children
June marries Shemp, and they have 2 daughters and a son, all three of which are colorblind.
August marries Daffy (who is colorblind), and they have 1 daughter, who is also colorblind.

7. Questions
1. Which of Jack and Jill’s daughters (April, May, June, and August) are DEFINITLY carriers for colorblindness?
2. Is Shemp colorblind? How can you be sure?

8. Analyze a Pedigree – how is hemophilia inherited?

9. The Blue People of Troublesome Creek, Kentucky
Methemoglobinemia is a rare condition in which the hemoglobin of individuals is different from normal. It causes people to have a characteristic blue color.
The hemoglobin does not carry oxygen as well as normal, so it is a type of anemia.
It can be caused by a rare allele. The most famous example is the Fugate family that lived in Kentucky over 100 years ago…

10. Fugate Family Tree
How is methamoglobinemia inherited?

11. Our Schedule
Monday: Quiz: dihybrids/advanced crosses & Pedigrees (P2 flywork/pedigrees)
Tuesday: Polygenic traits & pleiotropy (P2 FLY SEMINAR)
Wednesday: Review (P4 FLY SEMINAR)
Thursday: Unit Test, Cell Division and Classical Genetics (Problem set due)