Answer:
The correct answer is option E. "DNA in both daughter cells would be radioactive".
Explanation:
Radioactive thymidine incorporation has irremediable effects in thymine and cytosine in bacteria such as E. coli. Although there are some reports of recovery of E. coli from UV-irradiation DNA damage, the presence of radioactive bases such as thymine is often irremediable. Therefore, after a dividing culture of E. coli exposed to radioactive thymine divides, DNA in both daughter cells would be radioactive.
The answer is A. Oligotrophic lakes are clear and hence
have little vegetation in them (hence no net primary production) that
could initiate the process of eutrophication. Eutrophication is brought about when bacteria
break down the high amount of organic matter hence reduce the oxygen supply in
the waters.