Do Now 3.1 Objective: Use a pedigree to trace the inheritance of genetic traits through a family. Task: Copy the key into “pedigree basics” on the notes handout
Tracing Albinism CDE G AB Albinism: recessive trait (aa) 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? Parents C & D do not have albinism, yet they produced child that does. What does that tell us about their genotypes?
Your turn - Dwarfism CDEF G AB Hint: Look at E, F, and their offspring to determine what’s going on here!
Pedigrees and X-linked traits DO Now: Pattern baldness (example = Mr. T) is caused by a recessive allele carried on the X chromosome (X o = 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?
Something’s a Little different here
Make a pedigree! (Classwork) Jack and Jill are not colorblind. They have 4 daughters, April, May, June, and August. None of their daughters is 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.
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?
Analyze a Pedigree – how is hemophilia inherited?
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…
Fugate Family Tree How is methamoglobinemia inherited?
Our Schedule Tomorrow: Flyday 5: The Final Chapter Monday: Polygenic traits and cell division review Tuesday: Genetics review Wednesday: Test: Cell division and genetics