孟德尔遗传定律课件.pptxVIP

孟德尔遗传定律Mendel’s principles 1.1 Mendel’s ExperimentsGregor Johann Mendel(1822-84)Mendel, born in 1822, grew up in a rural area of what is now a part of Czechoslovakia. Because his family was poor, he entered a monastery in order to continue his education. Mendel had a lifelong interest in biology, particularly animal breeding, but because his superiors did not think it appropriate for a cleric to breed animals, he concentrated instead on raising garden peas and other plants in the monastery garden. 1.1 Mendel’s ExperimentsThe results of his work were published in German in an 1866 paper entitled “experiments in Plant Hybridization.” The paper was distributed fairly widely through libraries, but Mendel’s contemporaries did not understand his findings, probably partly because of the mathematical explanations astery in 1868 and published nothing further on heredity by the rest of the scientific community until 1900, when three botanists, Carl Correns in Germany, Hugo de Vries in the Netherlands, and Erich von Tschermak in Austria, rediscovered his work after each had apparently independently reached similar conclusions. 1.1.1 孟德尔遗传分析的方法严格选材从豆科植物中选择了自花授粉且是闭花授粉的豌豆作为杂交试验的材料。精心设计采取单因子分析法。定量分析法首创了测交方法 Why Mendel chose the pea plant?The garden pea was easy to cultivate and had relatively short life cycle.The plant had discontinuous characteristics such as flower color and pea texture.In part because of its anatomy, pollination of the plant could be controlled easily. Foreign pollen could be kept out, and cross-fertilization could be accomplished artificially. 1.1.2 Concerned concept杂交(cross): 在遗传分析中有意识地将两个基因型不同的亲本进行交配称杂交。F1 (Filial generation) : 由两个基因型不同的亲本杂交产生的第一代杂种，由F1自交或互交产生的第二代杂种称F2代。杂种(hybrid): 任何不同基因型的亲代杂交所产生的个体。Monohybrids: Offspring of parents that differ in only one genetic characteristic. Usually implies heterozygosity at a single locus under study. 1.1.2 Concerned concept显性基因(dominant gene)：在杂合状态下，能够表现其表型效应的基因，一般以大写字母表示。隐性基因(recessive gene)：在杂合状态下，不表现其表型