He was later sent to the University of Vienna to study. By both his professors at University and his colleagues at the monastery, Mendel was inspired to study variance in plants. He commenced his study in his monastery's experimental garden. Between 1856 and 1863 Mendel cultivated and tested some 28,000 pea plants. His experiments brought forth two generalizations which later became known as Mendel's Laws of Heredity. Ironically, when was published on 1866, it had little impact. It wasn't until the early 20th century that the enormity of hisideas was realized.
Mendel's hypothesis essentially has four parts. The first states that "Alternative versions of genes account for variations in inherited characters." In a nutshell, this is the concept of alleles. Alleles are different versions of genes that impart the same characteristic. Each human has a gene that controls height, but there are variations among these genes in accordance with the specific height the gene "codes" for. The second, "For each character, an organism inherits two genes, one from each parent", alludes to the fact that when somatic cells are produced from two gametes, one allele comes from the mother, one from the father. These alleles may be the same (true-breeding organisms), or different (hybrids). The third law, in relation to the second, declares that, "If the two alleles differ, then one, the dominant allele, is fully expressed in the organism's appearance; the other, the recessive allele, has no noticeable effect on the organism's appearance." "The two genes for each character segregate during gamete production," is the last part of Mendel's generalization. This references meiosis when the chromosome count is changed from the diploid number to the haploid number. The genes are sorted into separate gametes, ensuring variation.
The most important principle of Mendel's Law of Independent Assortment is that the emergence of one trait will not effect the emergence of another. While his experiments mixing one trait always resulted in a 3:1 ratio between dominant and recessive phenotypes, his experiments with two traits showed 9:3:3:1 ratios. Mendel's findings allowed other scientists to simplify the emergence of traits to mathematical probability. A large portion of Mendel's spectacular findings can be traced to his proper usage of the scientific method. His choice of peas as a subject for his experiments is extraordinarily lucky. Peas have a relatively simple genetic structure. Also, Mendel could always be in control of the plants' breeding. When Mendel wanted to cross-pollinate a pea plant he needed only to remove the immature stamen of the plant. In this way he was always exactly sure of his plants' parents. Mendel made certain to start his experiments only with true breeding plants. He also only measured absolute characteristics such as color, shape, and position of the offspring. His data was expressed numerically and subjected to statistical analysis. This method of data reporting and the large sampling size he used gave credibility to his data. He also had the foresight to look through several successive generations of his pea plants and record their variations. Without his careful attention to procedure and detail, Mendel's work could not have had the impact it made on the world of genetics.
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