„X Attempted to develop a vaccine against the Streptococcus pneumoniae bacterium

„X He isolated and cultured 2 different strains of the bacterium

„X Some colonies had a rough appearance (R strain)

„X Some had a smooth appearance (S strain)

„X Experimentation revealed that the R strain was harmless and the S strain was pathogenic (disease-causing)

„X Mice injected with live R cells plus heat-killed S cells died; the simplest explanation was that heat killed the S cells but did not destroy their hereditary material

„X Somehow the genetic material had been transferred from the dead S cells to the living R cells

„X They were able to transform harmless bacteria

„X Some enzymes can unwind the strands in both directions and prevent them from rewinding

l cells with extracts of killed pathogenic cells

Some topics in this essay:
REPLICATION REPAIR, Frederick Griffith¡¦s, Components DNA, Watson Crick, Enzymes DNA, Oswald Avery, A¡XT G¡XC, Salvador Luria, DNA RNA, „x dna, „x enzymes, double helix, DNA STRUCTURE, „x figure, strand double helix, dna ligases, replication „x, „« dna, strain „x, dna „x, double helix „x, appearance strain „x, strand „x,