Reminders Unit 8 Exam- Tuesday, March, 21st Last day to turn in ANY Unit 7 Work- Tuesday, March, 21st Assignments completed for Unit 8: Word Wall Human Traits Incomplete Dominance Practice Reminders
Unit 8: Mendelian Genetics 8.4 Other Patterns of Inheritance
Phenotype produced when both alleles are clearly expressed. Traits appear together Examples: Red and white spotted cattle (roan) AB Blood types (the A and B proteins appear on the surface of your blood cells together) Codominance
Using a Punnett Square for Codominance Use only capital letters- since there is no dominant trait Place the two traits onto the Punnett square, the same as you have before Cross the traits in the square Using a Punnett Square for Codominance
Example with Codominance Jessica has B blood type. Jessica’s mom has blood type O. Jessica has a baby with John, who has type AB blood. a. parent genotype b. offspring genotype c. offspring phenotype Example with Codominance
Sex-Linked The gene is carried on a sex chromosome (x or y) Occur most often in males because they don’t have another x Most of these genes are recessive, which means mom can be a carrier and pass the trait to her offspring Examples: Hemophilia Red-green color blindness Sex-Linked
Using a Punnett Square for Sex-Linked Determine the genotypes of the parents Mom is a carrier: Xx heterozygous Mom is NOT a carrier: XX homozygous Mom shows trait: xx homozygous recessive Dad “normal”: XY Dad with trait: xY Place the traits onto the Punnett square as you have before Cross the traits in the square Determine the genotype and phenotype of the offspring Male = XY, xY Female = XX, Xx Using a Punnett Square for Sex-Linked
Example with Sex-Linked Carol is a “carrier” for a recessive sex-linked trait that causes red- green color blindness. Carol has a baby with Bill, who is normal. a. parent genotype b. offspring genotype c. offspring phenotype d. proportion of male offspring e. Proportion of offspring with red-green color blindness.
Parents: The McBride’s: type O and AB (1 Punnett) The Gonzales’: type A and B (4 Punnetts) The Pepronis: type A and O (2 Punnetts) Children: Baby A is type AB Baby B is type O Baby C is type B 1. Who are the parents of baby A? A: Gonzales 2. Who are the parents of baby B? A: Pepronis 3. Who are the parents of baby C? A: McBride Practice In a hospital, 3 babies were born simultaneously during a thunderstorm. The lights went off and the babies were mixed up. The hospital wants to match the baby with its parents by looking at the blood types. Can you help?