Codominance Incomplete dominance and Multiple Alleles Directions Fill

Codominance, Incomplete dominance and Multiple Alleles. Directions: Fill in the guided notes as you go through the power point, make sure to quiz yourself before looking for the answers.

However… There are many exceptions to Mendel’s principles. Some alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or multiple genes

Think about this…. . These flowers both had one red parent and one white parent. Compare the ways in which they inherited their colors from their parents:

You should have said the pink flower on the left is a blend of the red and white parent mixed t The red and white flower on the right shows both colors in the phenotype.

Incomplete Dominance Neither allele is completely dominant over the other Example: Red flowers (RR) and White flowers (WW) make Pink flowers (RW) RR x WW = RW 3 phenotypes

Make a key! INCOMPLETE DOMINANCE In flowers RR = red WW = white RW = pink

Work this out on the left side of your notebook What are the genotypes and phenotypes of a cross between a red (RR) flower and a white (WW) flower if flower color is incompletely dominant? ?

Work this out on the left side of your notebook What are the genotypes and phenotypes of a cross between a pink flower and a red flower if flower color is incompletely dominant? ?

Work this out on the left side of your notebook What are the genotypes and phenotypes of a cross between a two pink flowers if flower color is incompletely dominant? ?

Codominance Both alleles contribute to the phenotype Both dominant phenotypes show up together in the heterozygous form RR x WW = RW (red and white TOGETHER) No Blending!!

Codominance or Incomplete Dominance?

If fish color were incompletely dominant instead of codominant, what color would the offspring be?

Make a key! CODOMINANCE in fish RR = Red BB = Blue BR = Patchwork (red and blue)

Work this out on the left side of your notebook Codominance: If a blue fish (BB) is crossed with a red fish (RR), what percentage of their offspring will be patchwork (BR)

Work this out on the left side of your notebook Codominance: If two patchwork fish (BR) mate, what genotypes and phenotypes will the offspring have?

Is this chicken an example of Codominance or Incomplete Dominance? How do you know? Explain using scientific language

Codominance In some chickens, black feathers are codominant with white feathers, so heterozygous chickens have black and white speckled feathers

Open the book to page 273 Read: Multiple alleles

For each genotype, give the phenotype: 1. Ccch full color 2. chc Himalayan 3. Cc Full color 4. cchcch chinchila Speed Round

Work this out on the left side of your notebook If a full color rabbit (Ccch) and an albino rabbit mate, what are the chances of a chinchila offspring ?

Work this out on the left side of your notebook If a full color rabbit (Cch) and a himalayan rabbit (chc) mate, what are the chances of a himalayan offspring ?

Multiple alleles = genes with more than two alleles Example: coat color in rabbits is determined by a single gene that has at least 4 alleles- page 273 Example: hair color is expressed by many different alleles

Open the book to page 273 What do you think Polygenic traits means?

Polygenic Traits Produced by the interaction of several genes. Example: skin color in humans is hei ght controlled by at least 4 genes Skin color Ey r o l o ec