1
Question
An exception to Mendel’s law of dominance was found in which of the following plants?
An exception to Mendel’s law of dominance was found in which of the following plants?
Open in App
Solution
The correct option is B Snapdragon
Mendel performed hybridisation experiments on garden peas and came up with some postulates. He proposed that something was getting transmitted from the parent to offspring through the gametes. He called these things as factors. The ‘factors’ represent the genetic basis of inheritance.
Mendel’s law of dominance states that: When parents with pure, contrasting traits are crossed together, one form of parental trait appears in the F1 generation out of the two traits. The trait that appears in the F1 hybrid is called the dominant trait. Hence the F1 hybrid resembles either of the two parents.
When Mendel’s experiments were repeated in different plants, it was found that sometimes the F1 had a phenotype that did not resemble either of the two parents and was intermediate between the two.
The inheritance of flower colour in the dog flower (snapdragon or Antirrhinum sp.) is a good example for this.
In a cross between true-breeding red-flowered (RR) and true-breeding white-flowered plants (rr), the F1 offspring was pink-flowered (Rr). When the F1 undergoes self-pollination, the F2 generation has offspring in the following ratio.
1 (RR) Red: 2 (Rr) Pink: 1 (rr) White.
This phenomenon is known as incomplete dominance.
Hence, an exception to Mendel’s law of dominance was found in snapdragon.
Mendel performed hybridisation experiments on garden peas and came up with some postulates. He proposed that something was getting transmitted from the parent to offspring through the gametes. He called these things as factors. The ‘factors’ represent the genetic basis of inheritance.
Mendel’s law of dominance states that: When parents with pure, contrasting traits are crossed together, one form of parental trait appears in the F1 generation out of the two traits. The trait that appears in the F1 hybrid is called the dominant trait. Hence the F1 hybrid resembles either of the two parents.
When Mendel’s experiments were repeated in different plants, it was found that sometimes the F1 had a phenotype that did not resemble either of the two parents and was intermediate between the two.
The inheritance of flower colour in the dog flower (snapdragon or Antirrhinum sp.) is a good example for this.
In a cross between true-breeding red-flowered (RR) and true-breeding white-flowered plants (rr), the F1 offspring was pink-flowered (Rr). When the F1 undergoes self-pollination, the F2 generation has offspring in the following ratio.
1 (RR) Red: 2 (Rr) Pink: 1 (rr) White.
This phenomenon is known as incomplete dominance.
Hence, an exception to Mendel’s law of dominance was found in snapdragon.
Suggest Corrections
1
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
