You are here : / / / 6 Reasons Why Your Gums are Bleeding. If you regularly see red when you brush your teeth, it could be cause for concern. Here's why your gums are bleeding ' and what to do about it. Jackie Middleton.
Between 1856 and 1863 Mendel cultivated and tested some 29,000 pea plants (Pisum sativum). This study showed that one in four pea plants had purebred recessive alleles, two out of four were hybrid and one out of four were purebred dominant.
In this example, he crossed a purebred white-flowered pea plant with a purebred purple-flowered pea plant. These plants are the parental, or P, generation. The resulting offspring, called the first filialâor F 1 âgeneration, all had purple flowers. The trait for white flowers seemed to disappear. When Mendel allowed the F 1 generation to self-fertilize, the resulting F 2 generation produced both plants with purple flowers and plants with white flowers. Therefore, the trait for white flowers had not disappeared; it had been hidden, or masked. traits that were hidden when parental purebred flowers were crossed reappeared when the F 1 generation was allowed to self-pollinate.