Question

$F_2$ generation has a phenotypic and genotypic ratio of 1:2:1. It is ____________
(a)Codominance
(b)Dihybrid cross
(c)Monohybrid cross with complete dominance
(d)Monohybrid cross with incomplete dominance

Answer 1

Hint: It is also known as partial dominance where both alleles of a gene are partially expressed creating a blend of the parental traits resulting in the genotype and phenotype of 1:2:1 of the $F_2$ generation. The flower color in snapdragon shows this type of inheritance.

Complete answer:
Incomplete dominance is a form of intermediate inheritance where one allele responsible for a particular trait is not expressed completely over the other paired allele. It's commonly seen in roses, Snapdragon where the pink color of the flowers is because of incomplete dominance.
Mechanism of incomplete dominance-
Let us consider the parent plants are Red-colored flowers and white-colored plants. A monohybrid cross between these two results in the formation of 4 pink colored flowers. This can be easily understood by the below cross-

When red roses, which contain the dominant red allele, are mated with white roses, which is recessive, the offspring will be heterozygotes and will express a pink phenotype.

When the Heterozygote pink-flowered plants were self-crossing the progeny had a ratio of $F_2$ federation is
Phenotypic ratio-1:2:1
Genotypic ratio-1:2:1
So, the correct answer is, ‘Monohybrid cross with incomplete dominance’.

Note: In humans’ incomplete dominance can be seen for the occurrence of wavy hair of the child. Tay-Sachs disease in humans is also an example of incomplete dominance