Non Mendelian Genetics Fold your paper so you

Non Mendelian Genetics

Fold your paper so you have 2 flaps opposite each other l l l Next cut three divisions on each side. You should have a total of 6, three on each side. Label the flaps on the left side: Codominance, Incomplete Dominance, and Polygenic Label the flaps on right side: Multiple Alleles, Lethal Recessive, Sex. Linked Codominance Multiple Alleles Incomplete Dominance Lethal Alleles Polygenic Sex-Linked

Codominance Both alleles contribute to phenotype NOTE: Two different letters for codominance can be used because both alleles are expressed together.

Incomplete Dominance – Heterozygous phenotype is halfway in between the two homozygous phenotypes l l Red flower x white flower = pink flower!!! RR X WW = RW

Multiple Alleles – Many genes have MORE than two alleles l l Human blood type (A, B, O) Blood type is written with the letter I to represent A and B which are codominant and i to represent O which is recessive.

Lethal Alleles l l alleles that cause the death of the organism that carries them Can be dominant or recessive

Polygenic Traits produced by interaction of more than one gene l Human skin color and height

Sex linked Traits l l Traits carried on the X or Y chromosome— mostly X Examples: color blindness, hemophilia, muscular dystrophy

No…really Y chromosome : • only 75 genes on Y (as compared to 800 on X chromosome) • traits on Y are passed from father to son, so if father has disorder, then so will son • very few Y-linked disorders are known