Gregor Johann Mendel - Born 20th July 1822 –Died 6 January 1884 was a scientist, Augustinian friar and abbot of St. Thomas' Abbey in Brno, Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire (today's Czech Republic) and gained subsequent recognition as the founder of the modern science of genetics. Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.
The Law of Segregation states that every specific organism contains two alleles (copies of a gene that differ from…show more content… The cross begins with the parental (P) generation. One parent is homozygous for one allele, and the other parent is homozygous for the other allele. The offspring make up the first family (F1) generation.(fig.4) Every member of the F1 generation is heterozygous and the phenotype of the F1 generation expresses the dominant trait. Crossing two members of the F1 generation produces the second family (F2) generation. Probability theory predicts that three quarters of the F2 generation will have the dominant allele's phenotype. And the remaining quarter of the F2s will have the recessive allele's phenotype. This predicted 3:1 phenotypic ratio assumes Mendelian inheritance.Conventional plant breeding is the advance or enhancement of cultivars using conservative tools for manipulating plant genome within the natural genetic boundaries of the…show more content… Methods for breeding cross-pollinated species include mass selection, recurrent selection, family selection and synthetics. Hybrid cultivar breeding exploits the phenomenon of heterosis, and is applicable to both self- and cross-pollinated species. Polyploids have complex genetics. Hybridization of parents is often accompanied by infertility of the hybrid. Mutation breeding may be resorted to when the gene of interest is non-existent in nature and may be induced. Also, sometimes, the desired trait is found in wild relatives of the species and may be introgressed into cultivated species through pre-breeding.Various systems for organisms have been devised throughout history, but a seventeenth century Swedish botanist, Linnaeus, laid the basis for much subsequent work in the classification of plants, animals (and also minerals). The original divisions of the plant kingdom were the main groupings of organisms according to their place in evolutionary history. Simple single-celled organisms from aquatic environments evolved to more complex descendants, multicellular plants with diverse structures, which were able to survive in a terrestrial habitat, and develop sophisticated reproduction