Question

Explain the Carl Correns's monohybrid cross in Four O'clock plant with the help of schematic representation. Mention the phenotype ratio and genotype ratio of plants occurred in $F_2$ generation.

Answer 1

Carl Correns's work on four o'clock plants led to the discovery of the concept of incomplete dominance. His experiments showed that a cross between red (RR- dominant characteristic) and white (rr- recessive character) flowered four o' clock plants yielded pink flowered four o'clock plants demonstrating incomplete dominance as shown in the schematic diagram above. In the F${}_2$ generation the parent traits can be seen again. The phenotypic ratio in the F${}_2$ generation is 1:2:1 (white:pink:red) and the genotypic ratio is also 1:2:1 (rr:Rr:RR).