BSC 114 Lecture Notes - Lecture 15: Nucleosome, Polynucleotide, Dna Ligase
1 Nov 2016
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Document Summary
In the early 20th century, the identification of the molecules of inheritance loomed as a major challenge to biologists: when t. h. Morgan"s group showed that genes are located in chromosomes, the two components of chromosomes (dna and protein) became candidates for the genetic material (molecule of inheritance) The key factor in determining the genetic material was choosing appropriate experimental organisms. The role of dna in heredity was first discovered by studying bacteria and the viruses that infect them, bacteriophages (aka phages: the discovery of the genetic role of dna began with research by frederick griffith in 1928. Worked with two strains of a bacterium, a pathogenic s strain and a harmless r strain. When he mixed heat-killed remains of the pathogenic strain with the living cells of the harmless strain, some living cells became pathogenic. Transformation- a change in genotype and phenotype due to assimilation of foreign dna.
