Anna and Kristoff are heterozygous for three traits (PTC taster, dimples and freckles). What is the chance of:1. Their child having the same characteristics as

them?2. Their child being recessive for all 3 traits?

Science Starter

Genetics After Mendel

Huh?

Incomplete Dominance One allele is not completely dominant over the other

Results in a combined phenotype Example: Snapdragons

Cross two pink snapdragons:

More than 2 alleles for a geneHuman Blood Type- IA, IB, i

Multiple Alleles

Two alleles are dominant

Codominance

On a recent episode of Jerry Springer, a woman brought her husband on the show (who recently moved out) to get him to pay child support for their baby. He claims that the baby she just had is not his, that it is her boyfriend’s!!! His argument is that he has type A blood and his wife has type B blood. The baby’s blood type is O so there is no way that the child is his. They come to you to determine the paternity of the baby. Is there any chance that this baby is his? (Hurry up with your answer; the husband just threw his chair at the boyfriend and they are about ready to fight!)

Jerry Springer Genetics Problem

Genes carried on the X chromosome Males fully express all alleles on X chromosome

Example: color blindness, hemophilia, ALD

Sex Linked Genes

Colorblindness Test

Cross a colorblind male with a normal female

More than one gene controls a trait Examples: Human height, weight, eye color, skin color, hair color, etc.

Polygenic Inheritance

Lab: Human Inheritance

PedigreeA chart that shows the presence or absence of a trait within a family

= female or = express trait

= male or = carrier

Sample ProblemDimples in the cheeks are inherited as a dominant trait on an autosome. Using the proper form and symbols, draw a pedigree chart, beginning with a heterozygous, dimpled father (Dd), and a nondimpled mother (dd). Show four children of the expected types: boys, girls, dimples and no dimples. Label your pedigree with phenotypes and genotypes.