Scarica Mendel, known as the "father of modern genetics", chose to study variation in plants e più Guide, Progetti e Ricerche in PDF di Diritto ed economia politica solo su Docsity! Mendel’s experiment The eight years Mendel was talking about were the eight years he spent collecting the data used in his paper. In fact, before that, he conducted experiments for two years to select the best materials. So actually, it took ten years before the paper was published. After ten years of experiments, the paper was published two years later. After the paper was published, he conducted research using other plants for several years. In the section "Selection of Plants for Experiments," Mendel states: "The value and usefulness of any experiment depends on whether the materials used are suitable for its purpose, so it is not unimportant what plants are chosen and how the experiment is performed... The plants must be selected with special care, starting from the beginning." Avoid obtaining questionable results." The plants he selected firstly have constant differentiation characteristics; secondly, they will not be contaminated by foreign pollen when crossing; in addition, the fecundity of each generation of hybrid offspring cannot change. Mendel's so-called "differentiating characteristics" are now called "characters" (such as height, color); his "constancy" means that the same character does not change between different generations; he paid attention to avoid contamination by foreign pollen, fearing that he would not know the exact parentage , the research results cannot be analyzed; he also paid attention to the fact that there is no change in fecundity between generations to reduce interference in the quantitative analysis of traits. Later generations believe that Mendel may have considered more than twenty kinds of plants in order to select suitable experimental materials. Mendel said he tried leguminous plants (Leguminosae) because of their strange flower shapes, and then decided to use peas (Pisum). Mendel was not very sure about the exact biological classification of the peas used, saying "expert opinion" said most were Pisum sativum and several others, although he made it clear that classification was not important to his research. Using peas also has the advantages of experimental operation not explained in the paper: it can both self-pollinate and cross-pollinate, and it is easier to control artificially. In 1854 and 1855, Mendel tried 34 different varieties of peas. Among Mendel's few relics is an order for peas from 1856. In "Experimental Division and Arrangement", Mendel selected the traits to be studied: he selected pairs of traits and studied their transmission rules between generations. These traits are stably inherited across generations and are easy to identify and differentiate. He selected 7 pairs of traits: seed shape (smooth or wrinkled), seed color (yellow or green), pod color (yellow or green), pod shape (bulging or narrow), flower color (purple or white), flower position (top or side), stem height (long or short). Among them, Mendel described the flower colors as "gray, taupe, leather brown, and velvet-red", which later generations simply referred to as purple and white. Corresponding to 7 pairs of traits, Mendel arranged 7 experiments. Experiment 1 used 15 plants for 60 pollinations; Experiment 2 used 10 plants for 58 pollinations; Experiment 3 used 10 plants for 35 pollinations; Experiment 4 used 10 plants for 40 pollinations; Experiment 5 Five plants were used for 23 pollinations; Experiment 6 used 10 plants for 34 pollinations; Experiment 7 used 10 plants for 37 pollinations. In all experiments, Mendel conducted two-way crosses: for a pair of traits, such as yellow and green seed colors, he had both male parent yellow and female parent green, male parent green and female parent yellow. He discovered the source of the parent Does not affect the passage of these traits. In the "Appearance of Hybrids" section, he further explains the selection of traits. He specifically selects that the traits of the offspring must be the same as those of the father or mother, rather than between the parents or other variations. Mendel knew that
