Method of Study (Mendel’s Experiment)

Method of Study (Mendel’s Experiment)
Mendel planted seeds and grew plants of different varieties of pea. He then made crosses between plants with contrasting characters such as green seeds colour versus yellow seed colour, wrinkled seed coat versus smooth seed coat, etc. Mendel observed pattern of inheritance of characters in succeeding generations and maintained complete statistical record of each cross.
In one of his experiments, Mendel made a cross between pure breeding pea plant having yellow seeds with a pure breeding pea plant with green seeds. He found that in F1 generation (first filial generation) all plants had yellow seeds. These plants were then allowed to be self fertilized to produce the F2 generation. The F2 generation contained both plants with green seeds in the ratio of 3:1. This ratio is called the monohybrid ratio. Same results were obtained for crosses involving six other pairs of contrasting characters and the ratio of dominant to recessive was 3:1.
Conclusions and Results
From the above experiments, Mendel made following conclusions
1. For each trait an organism inherits two factors (genes), one from each parent.
2. Out of a pair contrasting characters, only one appeared morphologically in F1 generation and the other did not show itself. The character taht expressed itself morphologically is called dominant and the other character, which did not appear is known as recessive. This fact is also referred as the Law of Dominance. Thus in pea plant, tall stem is dominant over dwarf stem, round seed coat is dominant over wrinkled coat, yellow seed colour is dominant over green seed colour etc