Generation titles P generation = parents F1 generation = offspring generation 1 (Latin filial = son) F2 generation = offspring generation 2 (from F1 self fertilization)

Codominance For a trait that is codominant, heterozygotes display BOTH phenotypes. Look at the example of horses RR = Red fur rr = White fur Rr = Red AND White fur (roan)

Codominance – Roan Horses

Incomplete Dominance The heterozygote genotype has a blend of both possible homozygous phenotypes. RR rr Rr

Shh! Don’t say a word! Write down what numbers (if any) you can read in each circle

Are you color blind? 4 Sex-Linked Traits: 1. Normal Color Vision:  A: 29,  B: 45,  C: --,  D: 26   2. Red-Green Color-Blind:  A: 70,  B: --,  C: 5,  D: --   3. Red Color-blind:  A: 70,  B: --,  C: 5,  D: 6   4. Green Color-Blind:  A: 70,  B: --,  C: 5,  D: 2

There are a LOT more color blind men than women!

Try One – as sex-linkage example in notes A female with normal vision that has 1 copy of a colorblindness gene (genotype X+ Xo) has children with a normal male (X+ Y). A. What % of their male children will be colorblind? B. What % of their female children will be colorblind? C. Do all colorblind women have a colorblind father? Explain

3 Different Alleles: Multiple Allele Traits The three alleles that determine blood type are represented as IA, IB, and i. Phenotype Genotypes A IAIA, IAi B IBIB, IBi AB IAIB O ii

Crosses A woman with blood type A has a baby with blood type O. The man she believes to be the father has the blood type AB. Is it possible the man is the father of the baby?

He isn’t the Father! IAIA (A) IAIB (AB) i IAi IBi (B) mom Possible dad