Fnord babies ~ will be collected ~ In Fnords, orange (O) fur is dominant over blue fur (o). An orange fnord and a blue fnord mate, and produce 314 orange offspring and 307 blue offspring. A.What is the genotype of the orange parent? B.Two of the orange F 1 fnords mate, and they produce both orange and blue offspring. If they have 98 blue babies in the F 2 generation, about how many orange ones are there? C.Describe a cross you could make to figure out if one of the orange fnords from the F 2 is homozygous dominant or heterozygous.

Which is Haploid? Which is Diploid? Haploid Diploid

Which is Genotype? Which is Phenotype? Phenotype Genotype bb

Which is Homozygous? Which is Heterozygous? Heterozygous Homozygous

Testcross A testcross is used to determine if an organism with a dominant phenotype is homozygous or heterozygous, by crossing it with a homozygous recessive individual

Codominance For a trait that is codominant, both alleles affect the phenotype, and the result is offspring that have 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 RR RR’ R’R’ For a trait that shows incomplete dominance, one allele has an effect, and the other does not. If there are two copies, the organism gets a “double dose” of the effect (red flower on left)

Flower Power If you crossed two of the pink flowers on the previous slide, –What % would be pink? –What % would be red? –What % would be white?

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: 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

There are a LOT more color blind men than women!

Try One – on the back of your drill A female with normal vision that has 1 copy of a colorblindness gene (genotype X + X o ) 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 Use Punnett squares to support each answer!

Wrap up What you SHOULD HAVE learned: –testcross –Codominance –Incomplete Dominance –Sex-linked inheritance