## Mendel's work with plants and bees

In 1856, Mendel began experimenting with the crossing of one quite ordinary plant - the pea, Pisum sativum. As it turned out later, this choice was very lucky, because pea plants grow quickly, are quite undemanding, can be propagated in a controlled manner, and what was also very useful, especially in the 19th century, peas can also be used in the kitchen! However, whoever thought that it was an easy job would be very mistaken. In order to keep everything under control, Mendel removed all the stamens (the male parts of the flower that produces pollen) from the undeveloped bud and using a brush transferred pollen from another plant to the scar (the place on the plant main stem/trunk where a leaf has fallen off). He then covered the flowers with paper cones or gauze bags. In this way, Mendel combined pollen with egg cells found in pistils (the female parts of the flower) with different characteristics and watched how individual characters were transmitted to the next generation. In total, he studied more than 29,000 pea plants. Mendel statistically evaluated the results of his long-term observations and presented them at two meetings of the Brno Natural History Association. However, his appearance had only a lukewarm response, and Mendel's results did not find a response in the scientific community even at the time of their publication in 1866, in a publication entitled "Experiments with plant hybrids" (from the German original “Versuche über Pflanzen-Hybriden“).

On the recommendation of Carl Nägeli, a scientific authority at the time, Mendel wanted to test his rules on another plant species. His choice fell on the hawkmoth (Hieracium), which had one feature that Mendel had no idea about, and which disqualified the hawkmoth as a model organism for studying the foundations of heredity. This genus of plants reproduces apomictically, which means that a new plant can arise from the egg without fusing with the male sex cell. Therefore, Mendel could not obtain the same results for this type of organism as for the pea, which reproduces sexually.

Mendel did not limit himself to plant breeding in his experiments on controlled crossing. As an enthusiastic beekeeper, he tried to breed stingless bees. Unfortunately, even this selection of a model organism did not lead to easy-to-understand results, mainly due to the specific method of determining the sex of bees. Mendel's results were based on mathematical and statistical models, which were not very popular in biology at that time. This fact, and Mendel's underestimation of his own results, meant that his extraordinary research was not understood by the natural scientists. As has often happened in history, Mendel's experiments gradually fell into oblivion, and it was not until two decades after his death that he received the attention he deserved. Thus, Mendel was unlucky in two of his three important experiments. However, the first (and most important) experiment finally made up for it, and when years later he was appreciated by the scientific community, Mendel was found to have laid the foundations for our current understanding of genetics and ensured him an important place in the history of natural sciences.