Question

Describe the inheritance of flower color in snapdragon

Answer 1

Inheritance of flower colour in snap dragon is a classic example for incomplete dominance.
In a cross between true breeding red flower (RR) and true breeding white flower (rr) produced a pink flower (Rr).
When the pink coloured flower of F1 generation were selfed, F2 generation produced plants with red flowers, pink flowers and white flowers in the ratio of 1:2:1. Here both red and white flowers were not dominant over each other. Both tried to express their traits and hence an intermediate colour of both red and white resulting in pink colour flowers.

No need to draw the diagrams. Just show the cross, phenotype and genotype.

In Codominance in F2 generation, the offspring will resemble both the parents. A classic example of co dominance is Human ABO groups. ABO blood groups are controlled by the gene I. The plasma membrane of the red blood cells has sugar polymers that protrude from its surface and the kind of sugars is controlled by the gene. The gene I has three alleles IA,IB and i. The allele IA and IB produce a slightly different sugar form while allele “I “doesn’t produce any sugar. As human beings are diploid an individual can have any two of the three alleles. IA and IB are co dominant while IA and IB are dominant over. When IA is present in both homozygous or heterozygous condition, the blood group will be “A” with IAIA or IAi conditions.
When IB is present in IBIB or IBi condition, it produces the blood group “B”. When IAIB come together, it results in blood group “AB”. When ii is present together, it results in blood group “O”.

#BeBrainly