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Mendel's Law Simplified: For centuries scientists, physicians and philosophers had been trying to understand the secrets of heredity. From 1856 to 1865, Johann Gregor Mendel bred and raised pea plants, having had some training in statistics. He knew he had to study large numbers of plants, so he identified traits in thousands of plants.
Mendel called the original parents P1 for parent generation and the offspring of the cross F1 for the first filial generation. He called the next cross F2 for second filial generation. When Mendel crossed tall pea plants with the short pea plants of the P1 generation, all of the F1 plants were tall. The same thing happened with each of the seven traits, only one form of each characteristic appeared in the F1 plants. To find out where the characteristic for short plants had went, he crossed the F1 plant to the F1 plant to get F2 plants, in which appeared the short plants again. Not only did it reappear but with a certain predictable mathematical relationship, 1 short and 3 tall. The same relationship, also, showed up for all of the seven traits. The patterns he found in his experiments formed the basis of our present knowledge of genetics. 1. 2. 3. 4. Additonal studies proved the following of dominate color: 1. The color does not skip a generation. 2. On the average a relatively large number of the progeny are affected. 3. Only affected individuals carry the color. 4. With color of this sort, there is less danger of continuing undesirable color in a strain, than is the case with recessive color. 5. The breeding formula for each individual is quite certain. and the following of recessive color: 1. The color may skip one or more generations. 2. On the average a relatively small percentage of the individuals in the strain carry the color. 3. Only those which carry a pair of genes for that color (exhibit it). 4. Those carrying only one gene can be seen only by mating, hence there is much more danger of accidentally contaminating the strain than is the case with dominant color. 5. The color must come from both sides of the family. Homozygous is an animal carrying the same form of a gene such as B B. Hetrozygousity is an animal that carries two different forms of the same gene such as B b. In 1865 Mendel, science teacher and abbot in the monastery of St. Augustine at Bruenn, published a paper on Experiments of Plant Hybridization. He described his experiments in the garden of the monastery and the laws of genetics that he concluded from this. Mendel's Law covers the basic understanding of inheritance.
Note that only one letter goes in each box for the parents. It does not matter which parent is on the side or the top of the Punnett square. Next, all you have to do is fill in the boxes by copying the row and column-head letters across or down into the empty squares. This gives us the predicted frequency of all of the potential genotypes among the offspring each time reproduction occurs. |
b b B b b b B b b b b b b b b b b b b b
