Word: spore
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Dates: during 1940-1949
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Knudson's X-rays produce their changes not by affecting the chromosomes, but rather the chloroplasts themselves. Reason: chloroplasts are passed on directly from parent plant to its offspring through the seed or spore instead of arising anew in each generation under the genetic influence of the chromosomes. Knudson worked with fern spores, because they are simple and sexlessly reproductive...
...most intensive disease-spreading was under way last week in Maryland, where it is subsidized with State funds and helped by the U.S. Department of Agriculture. This week a similar campaign begins in New Jersey, where the first few spores were sown in 1939. The method is to heavily infect two half-acre plots of turf (where grubs thrive best) in each square mile. Birds, breezes and flying beetles then complete spreading the disease. Purpose of spore-sowing is not, as in spraying, to kill beetles on a specific plot but to establish the beetle enemy widely. Spore powder...
Then Dubos found in soil samples a spore-bearing bacillus which actually kills five kinds of pneumococcus; staphylococcus (the pus germ), streptococcus, the diphtheria bacillus. The killing agent is a non-protein substance which Dr. Dubos has isolated in crystalline form. One hundred-thousandth of a gram* of the stuff is enough to destroy a billion pneumococci in two hours...