Question

Which one of the following is not a case of incomplete dominance?

• A. Flower colour of Camellia
• B. Flower colour of snapdragon
• C. Flower colour in Mirabilis jalapa
• D. Fruit colour of eggplant (brinjal)

Answer 1

The correct option is A Flower colour of Camellia

In incomplete/partial or semi-dominance, when a cross between contrasting homozygous traits give rise to a heterozygous phenotype which is in between the homozygous phenotypes. Basically heterozygotes are blend of the homozygous phenotypes. Incomplete dominance is the situation where the neither of the parental genotypes sufficiently dominate over the other in hybrid conditions to produce a phenotype of its own. Examples of incomplete dominance are like- Flower colour in Snapdragon (Antirrhinum majus), flower colour in 4 o’clock plant (Mirabilis jalapa), fruit colour in eggplant (brinjal) etc.
But the flower colour of Camellia shows co-dominance phenomena.
When two Camellia plants with white-flowers and the red-flowers are crossed, the petal colour in the flower of the progeny shows codominance and is expressed as red-white petals.