Beth Howard Genetics

Definition of Incomplete Dominance:

In Non-Mendelian Genetics, Incomplete Dominance results in the offspring phenotype (trait)

• being a mixture or blend of the two parent phenotypes (traits).

• showing both of the two parent phenotypes.

• having one dominate and one recessive trait

• showing the recessive trait of the parents.

Incomplete Dominance Question 1:

In snapdragons, flower color is controlled by incomplete dominance. The two alleles are red (RR) and white (WW). The heterozygous genotype is expressed as pink (RW).

a. What is the phenotype of a plant with the genotype RR?

• Red

• White

• Pink

• Green

Incomplete Dominance Question 1-

In snapdragons, flower color is controlled by incomplete dominance. The two alleles are red (RR) and white (WW). The heterozygous genotype is expressed as pink (RW).

b. What is the phenotype of a plant with the genotype WW?

• Red

• White

• Pink

• Green

Incomplete Dominance Question 1-

In snapdragons, flower color is controlled by incomplete dominance. The two alleles are red (RR) and white (WW). The heterozygous genotype is expressed as pink (RW).

c. What is the phenotype of a plant with the genotype RW?

• Red

• White

• Pink

• Green

Incomplete Dominance Question 2-

Predict the offspring when two pink snapdragon flowers (RW) are crossed.

(Work out Punnett Square on Paper)

a. What is the predicted genotypic ratio for the offspring?

(In Incomplete Dominance Genotypic Ratios Are Written Out By Number and Genotype: There is NO SPECIFIC ORDER)

• 1 RR: 2 RW:1 WW

• 2 RR: 1 RW: 0 WW

• 0 RR: 2 RW: 1 WW

Incomplete Dominance Question 2:

Predict the offspring when two pink snapdragon flowers (RW) are crossed.

b. What is the predicted phenotypic ratio for the offspring?

(In Incomplete Dominance Phenotypic Ratio's are written out by number and Phenotype: There is NO SPECIFIC ORDER)

• 1 Red: 1 White: 2 Pink

• 2 Red: 1 White: 2 Pink

• 1 Red: 1 White: 4 Pink

Tags

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Incomplete Dominance Question 3:

A pink-flowered plant is crossed with a white-flowered plant. What is the probability of producing:

(Work out Punnett Square on Paper)

a. A pink-flowered plant?

• 50%

• 25%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

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Incomplete Dominance Question 3: A pink-flowered plant is crossed with a white-flowered plant. What is the probability of producing:

(Work out Punnett Square on Paper)

b. A red flowered plant?

• 0%

• 25%

• 75%

• 50%

Incomplete Dominance Question 3:

A pink-flowered plant is crossed with a white-flowered plant. What is the probability of producing:

c. A white flowered plant?

• 25%

• 50%

• 75%

• 110%

Tags

NGSS.HS-LS3-3

Incomplete Dominance Question 3d:

What cross will produce the most pink-flowered plants?

• RR x WW will produce to highest percent chance of an offspring with a pink phenotype.

• RW x WW will produce to highest percent chance of an offspring with a pink phenotype.

• RW x RR will produce to highest percent chance of an offspring with a pink phenotype.

• RR x RR will produce to highest percent chance of an offspring with a pink phenotype.

Tags

NGSS.HS-LS3-3