Word: transfering
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Dates: during 1970-1979
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...STudents who leave either transfer to another school or go through a personal identity crisis and never return to higher education," Whitlock said. "No one really knows what happens to them...
Unlike eukaryotes, prokaryotes ordinarily reproduce by the asexual process of cell division. Their occasional gene transfers do not show a sharp species boundary: the transfer simply becomes less efficient the greater the evolutionary separation between the donor and the recipient. Prokaryotes therefore have no true species: they have an almost continuous spectrum of genetic patterns, and the borders between what we call bacterial species are arbitrary and often controversial. E. coli, for example, is the name given to a range of strains with certain common features but also with a variety of differences, and these differences determine their relative Darwinian...
...particular, it is known that bacteria can take up naked DNA from solution; and, in fact, transfer of DNA between two strains of pneumococcus has been demonstrated in the animal body. Moreover, bacteria in the gut are constantly exposed to fragments of host DNA that are released as the cells lining the gut die, and bacteria growing in carcasses have a veritable feast of DNA. The efficiency of such uptake of mammalian DNA by bacteria is undoubtedly very low. However, because of the extraordinarily large scale of the exposure in nature, recombinants of this general class must have been formed...
...Strain K12 of E. coli has become adapted to artificial media during transfer for at least 30 years in the laboratory. Recent tests in England showed that after a dose in man much larger that what one would expect from a laboratory accident, it disappeared from the stools within a few days. Its problems of survival are analogous to those of a delicate hothouse plant thrown out to compete with the weeds in a field...
...very large safety factor is added by the provision in the present Guidelines for biological containment. All work with mammalian DNA must be carried out only in an EK2 strain, which has a drastically impaired ability to multiply, or to transfer its plasmid, except under very special conditions provided in the laboratory...