Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sometimes inheritance does not follow Mendel’s rules (Non-Mendelian Genetics) X=X= X=X = Skin Tone Eye Color

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Incomplete Dominance The heterozygous phenotype is a blend of the dominant and recessive Rr R r R r R R r r RR rr

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Codominance Both alleles are expressed Rr R r R r R R r r RR rr RR rr Rr RR rr

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Codominance

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Population affected with Sickle Cell Anemia Population with a high risk of contracting Malaria Malaria Animation

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Multiple Alleles There are more than 2 alleles for a particular trait For blood type in humans there are 3 alleles A B O (ABO blood type) A & B are Co-Dominant & O is Recessive

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Type A Type B Type AB Type O A A B B A & B none B B A A A & B A & AB B & O AB All O O B & AB A & O Blood Types Antigen Antibody Can Give to: Can Receive From:

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance IAIA i IBIB i I A I B I B i I A i i Type A Type B Type AB Type O I A I B I A I A or I A i I B I B or I B i i Phenotype Genotype What are the possible blood types for the children of a heterozygous type A woman and a heterozygous type B man?

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance What are the possible blood types for the children of a heterozygous type A woman and a heterozygous type B man?

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Polygenic Traits more than one pair of genes code for a particular trait The occurrence of the phenotypes of a polygenic trait usually form a bell curve

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sex determination in humans

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sex determination in humans X Y X X XX XY XX x XY

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sex-Linked Traits Traits found on the sex chromosomes More traits are found on the X-chromosome than the Y

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sex-Linked Traits Red-green colorblindness and hemophilia are x-linked, recessive disorders

Ch.11 – Complex Inheritance & Human Heredity 11.2 – Complex Patterns of Inheritance Sex-Linked Traits Females are far less likely to have an x-linked recessive disorder. XBXB Y XBXB XbXb XBXBXBXB XBXbXBXb XBYXBY XbYXbY A cross between a carrier female and a male with normal vision will lead to the following:

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity Genetic Disorders Autosomal Recessive Disorders. Cystic Fibrosis Albinism Tay-Sachs Defective membrane protein leads to digestive & Respiratory failures Little to no melanin production which causes skin and eye damage from UV rays Inability to break down fatty substances leads to a buildup in the brain and mental disabilities

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity Genetic Disorders Autosomal Dominant Disorders. Huntingtons Achondroplasia Decline of mental and neurological function Dwarfism

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity Pedigree Analysis (Inter-family) (The subject being studied)

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity Which shows a dominant and which a recessive autosomal disorder? Recessive Dominant (or recessive)

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity Sex-Linked Recessive

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity What are the genotypes for I-1 & I-2? II-1 & II-2? III-1, III-2 & III-3? Aa A? aa Aa A?

Ch.11 – Complex Inheritance & Human Heredity 11.1 – Human Heredity When carriers are shown on a pedigree you know all genotypes (sometimes carriers are shown sometimes they are not) XAXaXAXa XAYXAY XaYXaY XAXAXAXA

Ch.11 – Complex Inheritance & Human Heredity 11.3 – Chromosomes & Human Heredity Kleinfelter’s Syndrome Down Syndrome Chromosomal Disorders

Ch.11 – Complex Inheritance & Human Heredity 11.3 – Chromosomes & Human Heredity Nondisjunction

Ch.11 – Complex Inheritance & Human Heredity 11.3 – Chromosomes & Human Heredity Trisomy will usually cause death very early in pregnancy. Trisomy 13,15,18, & 22 have been documented (most die before age 1) Trisomy 21 Down Syndrome abnormal facial appearance, high likelihood of mental retardation (degree varies considerably), and increased likelihood of developing leukemia and Alzheimer’s disease

Klinefelter’s Syndrome Underdeveloped reproductive organs & infertility. May also cause Enlarged breasts & a decrease in mental function. Ch.11 – Complex Inheritance & Human Heredity 11.3 – Chromosomes & Human Heredity Nondisjunction in Sex Chromosomes Turner’s Syndrome Underdeveloped reproductive organs & infertility. Short stature and decreased mental function