genes in viruses and bacteria
In the 1940's the attention of geneticists was surprisingly focused on the Escherichia coli, colon bacterium. E. coli offered many advantages such as genetically being simpler, they are easily broken open and bacterial cells have little internal structure. For the fact that the E. coli populations can double in number in twenty minutes, viruses could be grown in enormous numbers in a short period of time. Viruses fall into the world between living and not living. They have traits of living yet they crystallize and develop like table salt. Hershey and Chase's classic experiment showed that viral SNA entered the bacterial host cell and left the empty coat outside. If viral SNA goes past the host's defenses it can come across a friendly host protein (RNA polymerase). RNA polymerase can't tell between its own DNA and foreign DNA. It treats the viral DNA as if it was its own and transcribes mRNA from it, making viral mRNA. Then making new viral enzymes, later taking over the hosts' mRNA. The last act of the viral protein is to lyse (rupture) the envelope of the host cell. Lysis of E. coli cell
Recombination is any exchange of DNA, and the first kind of recombination observed in bacteria was transfomation; which involved bacteria taking up fragments of DNA from other bacteria. Transduction is the transfer of genetic material from one bacterium to another using a bacteriophage as the carrier. Hayes and others were able to isolate several bacterial stains before long. The strains had the F plasmid being integrated into the host chromosome. These strains showed s promise for recombination of the main bacterial chromosome that was 1000 times greater than before. These were called the Hfr (high frequency of recombination). Joshua Lederberg and Edward Tatum worked on genetic recombination. They found a certain type of plasmid that's known as the F episome. It's name arrives from a "fertility plus" strain of bacteria. The positive bacteria moved across the sex pilus into the negative strain. In 1964 Lederberg and Tatum performed a simple yet imaginative experiment. They mixed two deficient strains of E. coli bacteria together to see what type of progeny occurred, then worked out lin
Some common words found in the essay are:
Hershey Chase's, RNA Recombination, Jacob Monod, , Lederberg Tatum, Elie Wollman, Edward Tatum, RNA DNA, Fred Waring, Life Wallace, host cell, mrna viral, bacteria sexduction, host chromosome, mating bacteria, larger pili, lederberg tatum, rna polymerase, viral sna,
Approximate Word count = 746
Approximate Pages = 3 (250 words per page double spaced)
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