GENETICS Many attempts have been made throughout history to explain the similarity between
parents and children.
People thought, for instance, that the substance responsible for
heredity came from both parents and were mixed together in the child. Based on this idea, it was said that the children''''s characteristics came from a mixture of the parents'''' blood. Traces of such conception are found in our still current expressions "royal blood" or "bloodline". Another theory suggested the existence of a miniature copy of the father in his reproductive cells ... But this is all passed and gone. We know, today, that heredity is
carried by the genes, which are chromosome sectors transmitted from parents to children.
The basic laws of heredity are studied by Genetics. These laws were stated by Augustinian monk Gregor Jonathan Mendel (1822-1884), in a monastery in the city of Brünn, Austria (now a Czechoslovakian territory).
Mendel used peas in his experiments because they could be easily observed. He cross-pollinated round peas with wrinkled peas. As a result, two thirds of the peas had pods containing both round and wrinkled peas. Mendel explained that the pollen grains of the peas had "factors that produced character" _ the genes. Today we know that these factors are located in the nuclei of the pollen and of the ovule. When fertilization occurs, the genes carried by the male nucleus are combined with those carried by the female nucleus, so that the new plant inherits half of its genes from each parent.
A report of his research was published in 1866, but remained unknown. It was only 34 years after publication, in 1900, that his work was "rediscovered" and fully understood by three scientists who worked separately: De Varies in Holland, Currents in Germany, and Tchemak in Austria.
It became evident that the Mendel in laws are important and effective for all organisms, including man, That is why Mendel is known as the "Father of Genetics".
By Fausto Fabio de Araujo