INHERITANCE PATTERNS Complete Dominance Codominance Incomplete dominance Multiple Alleles Polygenic Environmental Conditions

X-linked traits – traits located on the X chromosome Sex-influenced traits – the presence of male or female hormones influences the expression of certain traits. Ex. baldness

GENETIC SCREENING TESTS - examination of a person’s genetic makeup Amniocentesis – b/t 14th and 16th week Chorionic villi sampling (CVS) – b/t 8th and 10th week

Genetic marker – a short section of DNA that is known to have a close association with a particular gene nearby.

MULTIPLE ALLELES TRAIT = trait controlled by genes that have more than 2 alleles Any combo of 2 alleles produces different phenotypes Ex. Blood types 4 blood types – A, B, AB, O AB+ – universal acceptor O- - universal donor

3 alleles – IA , IB , Ii

3 alleles – IA , IB , Ii Genotype Phenotype IAIA or IAIi Type

3 alleles – IA , IB , Ii Genotype Phenotype IAIA or IAIi Type IBIB or IBIi

3 alleles – IA , IB , Ii Genotype Phenotype IAIA or IAIi Type IBIB or IBIi IAIB

3 alleles – IA , IB , Ii Genotype Phenotype IAIA or IAIi Type IBIB or IBIi IAIB Type O

3 alleles – IA , IB , Ii Genotype Phenotype IAIA or IAIi Type A IBIB or IBIi Type B IAIB Type AB IiIi Type O

Ex. If mom has IAIi and dad has IAIB, what are the chances of having a child with type B blood?