Principles of Inheritance and Variation Question 5
5. In Antirrhimum (Snapdragon), a red flower was crossed with a white flower and in $F_1$ generation, pink flowers were obtained. When pink flowers were selfed, the $F_2$ generation showed white, red and pink flowers. Choose the incorrect statement from the following:
[2019]
(a) This experiment does not follow the principle of dominance.
(b) Pink colour in $F_1$ is due to incomplete dominance.
(c) Ratio of $F_2$ is $\frac{1}{4}$ (Red): $\frac{1}{2}$ (Pink): $\frac{1}{4}$ (White)
(d) Law of Segregation does not apply in this experiment.
Show Answer
Answer : d
Hints & Solution
(d) Genes for flower colour in snapdragon shows incomplete dominance which is an exception of Mendel’s first principle (i.e. Law of dominance), whereas Law of segregation is universally applicable. Incomplete dominance is a process when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele, and the organism’s resulting physical appearance shows a blending of both alleles.
