Exceptions to Mendels Rules: Co-Dominance and Incomplete (Intermediate) Dominance

Exceptions to Mendels Rules: Co-Dominance and Incomplete (Intermediate) Dominance

Name:______

Exceptions to Mendels Rules: Co-Dominance and Incomplete (Intermediate) Dominance

  1. ______:
  1. Examples:
  2. ______snapdragon flowers crossed with white snapdragon flowers will produce ______flowers.
  3. A straight-haired person and a curly-haired person will have ______-haired baby.
  4. Punnett Squares: When crossing organisms with ______

you must be ______careful writing ______.

Sample Problem: Cross a red snapdragon with a white snap dragon. Write the genotypes and phenotypes.

  1. ______:
  1. Examples: Many animals exhibit this, including horses, cattle, and cats. The animal that is heterozygous will have ______colors.

Sample Problem: In horses, a roan color is produced when the animal has red hairs and white hairs. Cross a horse that is red with a horse that is white and write the genotypic and phenotypic ratios.

Practice

  1. Practice setting up keys for the phenotypes listed in each set. Remember that the “medium” trait must always be heterozygous.
  2. Birds can be blue, white, or white with blue tipped feathers.
  1. A Sneech can be tall, medium, or short.
  1. A Bleexo can be spotted, black or white
  1. Which letters above are an example of codominance?
  1. A horticulturist wants to make red flowers but only has pink flowers and white flowers. Draw a punnett square showing how the horticulturist can get red flowers? Use RR for red, RW for pink, and WW for white.
  1. A woman with straight hair (SS) marries a man with wavy hair (SW) what is the probability (as a %) that their child with have straight hair?
  1. A horse breeder has a customer who wants a red horse, but he only has 2 roan (red AND white) horses and 1 white horse to work with. Which two horses does the breeder need to breed to give the customer the red horse? Use a punnett square to support your answer.
  1. Checkered chickens (BW) are the result of (BB) and white (WW) feathers being expressed at the same time. What phenotypic ration would result from a cross between 2 checkered chickens?
  1. A gardener ordered pink flowers for his daughter’s wedding, but the company sent only red and white flowers. Draw a punnett square showing the gardener how he can fix his problem. Use RR for red, RW for pink, and WW for white.
  1. Which numbers (3-7) were examples of incomplete dominance?
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