Gregor Johann Mendel

Gregor Mendel was one of the first people in the history of science to
discover genetics. He independently discovered his work and lived in Brunn,
Czechoslovakia. In Brunn he was a monk and later the Abbot of the church in
Brunn. While he was in Brunn he performed many experiments with garden peas.
With the information he observed he wrote a paper where he described the
patterns of inheritance in terms of seven pairs of contrasting traits that
appeared in different pea-plant varieties. All of the experiments he performed
utilized the pea-plant, which in this case is the basis of the experiment.
Mendels work was reported at a meeting of the Brunn Society for the Study of
Natural Science in 1865, and was published the following year. Mendels paper
presented a completely new and unique documented theory of inheritances, but it
did not lead immediately to a cataclysm of genetic research. The scientists who
read his papers of complex theories, dismissed it because it could be explained
in such a simple model. He was rediscovered by Hugo de Vries in The Netherlands,
Carl Correns in Germany, and Evich Tschermak in Austria all at the same time
after 1900. They named the units Mendel described "genes." When the gene has a
slighty different base sequence it is called an "allele."

Mendel also developed 3 laws or principles. The first principle is
called the, "Principle of Segregation." This principle states that the traits of
an organism are determined by individual units of heredity called genes. Both
adult organisms have one allele from each parent, which gives both organisms 2
alleles. The alleles are separated or "segregated" from each other with the
reproductive cell formation. Mendel's second principle is the, "Principle of
independent assortment." This principle states that the expression of a gene for
any single trait is usually not influenced by the expression of another trait.
Mendel's third and last principle is called the, "Principle of dominance." This
principle states that an organism with contrasting alleles for the same gene,
has one allele that maybe dominant over the other (as round is dominant over
wrinkled for seed shapes in pea-plants). All the principles just stated are
Mendel's Laws of genetics.