Non-Mendelian Inheritance

Polygenetic Inheritance -a trait is controlled by more than two alleles Ex. Skin color Fig Eggs Sperm Phenotypes: Number of dark-skin alleles: / 64 6 / / / / 64 6 / 64 1 / 64 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 1/81/8 AaBbCc 

Sex Determination - out of 46 only 2 are sex chromosomes = X & Y - XX = female, XY = male -44 are autosomes- code for everything else

Sex Linked Genes - Carried on only the X or Y chromosome - Ex: Color blindness is a recessive trait carried only on the X chromosome (X C or X c ). A female needs to be X c X c to get it, but a male only has to be X c Y to get it. So more males are color blind. X C X C X c X C Y X c Y XCXC XcXc XCXC Y

Numbers That You Should See If You Are In One Of The Following Four Categories: [Some Letter Choices Show No Visible Numbers] 4 Sex-Linked Traits: 1. Normal Color Vision: A: 29, B: 45, C: --, D: Red-Green Color-Blind: A: 70, B: --, C: 5, D: Red Color-blind: A: 70, B: --, C: 5, D: 6 4. Green Color-Blind: A: 70, B: --, C: 5, D: 2

Pedigree- a chart showing genetic inheritance

Incomplete Dominance the alleles are blended together to form an intermediate phenotype - example:snap dragon color (red, white or pink)

Co-Dominance - Both alleles are expressed in the phenotype (ex. Sickle cell anemia) BB= normal cell bb=sickle cell Bb Both (carrier)

Blood Type -Co-dominant: - caused by multiple alleles – 3 or more types A = has only A carbs. B = has only B carbs. AB = both AB carbs. O = no carbs. Genotype Red blood cell appearance Phenotype (blood group) A B AB O

Fig IAIA IBIB i A B none (a) The three alleles for the ABO blood groups and their associated carbohydrates Allele Carbohydrate Genotype Red blood cell appearance Phenotype (blood group) I A I A or I A i A B I B I B or I B i IAIBIAIB AB iiO (b) Blood group genotypes and phenotypes

RH factor -Rhesus factor- antigens on the surface of blood cells that can cause an immune response -Positive (+) blood has antigens -Negative (-) blood has no antigens -a negative mother could harm a positive fetus. -a negative person getting positive blood can be harmed

Epistasis One gene alters the expression of another gene BbCc Sperm Eggs BCbC Bcbc BC bC Bc bc BBCC 1/41/4 1/41/4 1/41/4 1/41/4 1/41/4 1/41/4 1/41/4 1/41/4 BbCC BBCc BbCc BbCC bbCC BbCc bbCc BBCcBbCc bbCc BBccBbcc bbcc 9: 3 : 4 

Pleiotrophy Some genes control more than one trait. (ex. Pea flower and seed color are controlled by one gene)

Multifactorial genetics Multifactorial traits are affected by genotype and the environment Norm of reaction-phenotype range (more acid or aluminum results in darker flowers