Mendel, Gregor Johann << MEHN duhl, GREHG uhr YOH hahn >> (1822-1884), an Austrian botanist and monk, formulated the basic laws of heredity. His experiments with the breeding of garden peas led to the development of the science of genetics.
His life.
Mendel was born on July 22, 1822, in Heinzendorf, Austria (now Hyncice, near Krnov, in what is now the Czech Republic). His parents were peasants. In 1843, Mendel entered the monastery of St. Thomas in Brunn, Austria (now Brno, the Czech Republic). He became a priest in 1847. In 1851, the monastery sent Mendel to study science and mathematics at the University of Vienna. He returned to the monastery in 1853 and taught biology and physics at a local high school for the next 14 years. Mendel’s fame came from his research in the monastery garden. In 1868, Mendel was elected abbot of the monastery. From then on, his administrative responsibilities limited his opportunities for research.
His work.
In his experiments, Mendel studied the inheritance of seven pairs of traits in garden pea plants and in their seeds. These pairs included (1) rounded or wrinkled seeds and (2) tall or short plants.
Mendel bred and crossbred thousands of plants and observed the characteristics of each successive generation. Like all organisms that reproduce sexually, pea plants produce their offspring through the union of special sex cells called gametes. In pea plants, a male gamete, or sperm cell, combines with a female gamete, or egg cell, to form a seed.
Mendel concluded that plant traits are handed down through hereditary elements in the gametes. These elements are now called genes. He reasoned that each plant receives a pair of genes for each trait, one gene from each of its parents. Based on his experiments, he concluded that if a plant inherits two different genes for a trait, one gene will be dominant and the other will be recessive. The trait of the dominant gene will appear in the plant. For example, the gene for round seeds is dominant, and the gene for wrinkled seeds is recessive. A plant that inherits both genes will have round seeds.
Mendel also concluded that the pairs of genes segregate (separate) in a random fashion when a plant’s gametes are formed. Thus, a parent plant hands down only one gene of each pair to its offspring. In addition, Mendel believed that a plant inherits each of its traits independently of other traits. These two conclusions are known as Mendel’s Law of Segregation and his Law of Independent Assortment. Since Mendel’s time, scientists have discovered some exceptions to his conclusions, but his theories in general have been proved.
Mendel died on Jan. 6, 1884. His results were published in 1866 but went unnoticed until 1900.
See also Evolution (The synthetic theory); Heredity (Mendel’s laws).
