Catalyst 1.Define genotype. 2.Define phenotype. 3.Blue is dominant to white. A homozygous blue flower is crossed with a white flower. What are the genotypes?

Agenda Notes – Incomplete Dominance – Whiteboards Sponge Bob Practice Exit Ticket

Incomplete Dominance I can explain inheritance by incomplete dominance.

Patterns of Inheritance complete dominance incomplete dominance co- dominance multiple alleles sex-linked Remember that some traits, like height, are controlled by more than 1 gene

Some alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or multiple genes.

complete dominance incomplete dominance co- dominance multiple alleles sex-linked

Incomplete dominance is a pattern of inheritance in which neither allele is completely dominant over the other. The heterozygous phenotype is somewhere in between the two homozygous phenotypes. we CAN use two different letters to represent the different alleles genotype: phenotype: R = red W = white RRWWRW redpinkwhite In incomplete dominance, there are always 3 phenotypes. One is in the middle of the other two.

B = black W = white Coat color in mice exhibits incomplete dominance. BB ? black

B = black W = white Coat color in mice exhibits incomplete dominance. WW ? white

B = black W = white Coat color in mice exhibits incomplete dominance. BW ? gray

R = red W = white RR ? red Flowers exhibit incomplete dominance for petal color.

R = red W = white WW ? white Flowers exhibit incomplete dominance for petal color.

R = red W = white RW ? pink Flowers exhibit incomplete dominance for petal color.

T = tall S = short TT ? tall Human height follows a pattern of incomplete dominance.

T = tall S = short SS ? short Human height follows a pattern of incomplete dominance.

T = tall S = short TS ? medium height Human height follows a pattern of incomplete dominance.

Coat color in mice is incompletely dominant. Yellow and white-colored mice are homozygous, while cream-colored mice are heterozygous. If two cream- colored mice mate, what phenotypic ratio can we expect of their offspring? Solving an Incomplete Dominance Problem YW Y WY W W Y Y W Y W 1. Read the problem. Underline the known alleles. Identify the type of inheritance as incomplete dominance. 3. Circle and/or write down the genotypes of the parents. 4. Set up and solve Punnett Square. 5. Highlight and answer what the question is asking. 2. Choose a letter to represent each allele in the problem. Y = yellow; W = white parents: YW x YW yellow = white= cream = 1/4 = 2/4 = 25% 50% 25%

What type of inheritance? (Complete or Incomplete Dominance) Tall pea plants are crossed with short pea plants. All the offspring are tall. How do you know what type of inheritance it is?

What type of inheritance? (Complete or Incomplete Dominance) Having 10 fingers is dominant to having 12 fingers. A woman with 12 fingers has a child with a normal man and all their children have 10 fingers. How do you know what type of inheritance it is?

What type of inheritance? (Complete or Incomplete Dominance) A blue butterfly mates with a yellow butterfly. All their children are green. How do you know what type of inheritance it is?

What type of inheritance? (Complete or Incomplete Dominance) You have a black horse and a white horse on your farm. They have babies, and they’re all gray. How do you know what type of inheritance it is?

What type of inheritance? (Complete or Incomplete Dominance) You have a black horse and a white horse on your farm. They have babies, and they’re all black. How do you know what type of inheritance it is?

Agenda Notes – Incomplete Dominance – Whiteboards Sponge Bob Practice Exit Ticket

Whiteboard Practice Hair texture is incompletely dominant. If a curly haired woman (CC) is crossed with a straight haired man (SS), what percent of their offspring will have wavy hair?

Agenda Notes – Incomplete Dominance – Whiteboards Sponge Bob Practice Exit Ticket

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