You insert a fragment of sheep DNA into a plasmid containing an AmpR gene.You transform bacteria with the recombinant plasmid,and plate the cells on growth media containing the antibiotic ampicillin.Each colony on the plate arose from _____ that ____ to ampicillin.
A)a single cell;is sensitive B)many bacteria;are resistant C)many bacteria;are sensitive D)a single cell;is resistant
You grow a culture of bacteria and split it into two culture tubes.One sample of bacteria you treat with calcium and the other is not treated.You then attempt to transform the two samples with a plasmid.Both samples survive,but only the samples treated with calcium take up the plasmid.What is the most likely explanation for your results?
A)The bacteria use calcium as a source of energy to take up the DNA. B)DNA is degraded in the absence of calcium. C)The calcium makes the bacterial membrane more porous to DNA. D)Calcium precipitates DNA,preventing it from being taken up by cells. E)The bacteria require calcium to grow.