Incomplete dominance

Definition: Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a third phenotype in which the expressed physical trait is a combination of the dominant and recessive phenotypes.
Incomplete dominance is similar to, but different from co-dominance. In co-dominance, an additional phenotype is produced, however both alleles are expressed completely. Co-dominance is exemplified in AB blood type inheritance.

Examples: 

• A snapdragon flower that is pink as a result of cross-pollination between a red flower and a white flower when neither the white or the red alleles are dominant.

• A brown fur coat on a rabbit as a result of one rabbit's red allele and one rabbit's white allele not dominating.

• A child with wavy hair as a result of one parent's curly hair and the other's straight hair.

• An Andalusian foul produced from a black and a white parent is blue.

• A carnation that is pink that is a result of cross-pollination between a red carnation and a white carnation.

• A black sheep and a white sheep mate and have a grey sheep.

• A black dog and a brown dog mate and the result is a dog with a brindle coat.

• A white cat and a brown cat mate and the result is an orange cat.

• A tall horse and short horse mate and the offspring is off medium stature.

• A big American Bulldog and a small American Bulldog mate and their offspring is medium-sized.

• A long tailed dog and a short tailed dog mate and the offspring has a medium lengthened tail.

• A blue bird and a red bird mate and the resulting offspring have mixed colors.

• A light-skinned person and a dark skinned person produce a child with a skin color that is in between each.

• A brown rat and a white rat mate and create a rat with a mixed color coat.

• A short-haired dog and a long-haired dog mate and the resulting offspring have medium length hair.

• Tay-Sachs disease is an example of the result of incomplete dominance because the gene that makes the antibodies only creates half of the necessary antibodies which creates a vulnerability in the individual to get Tay-Sachs.

• One parent has a large lip protrusion, the other parent has a small lip protrusion and the child has an average lip protrusion.

• One parent has a high voice, the other parent has a low-pitched voice, so the child has a voice of medium pitch.

• Sickle cell disease is the result of incomplete dominance as those who have the disease carry 50% normal and 50% abnomal hemoglobin.

• If a red tulip and a white tulip are cross pollinated they result is a pink tulip.

• A highly spotted cat and a cat without spots has an offspring that has only some spots.

• A person with big hands and a person with small hands have offspring with hands of average size.

• A red bird and a blue bird mate and their offspring are purple.

• A brindle dog and a white dog mate and the offspring are a mix of white and brindle.

• A dog with eye patches and dog without eye patches breed and produce offspring with one eyepatch.