Bio 181 Exam #4 questions with 100% correct answers

Bio 181 Exam #4Suppose you are provided with an actively dividing culture of E. Coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? A. One of the daughter cells, but not the other, would have radioactive DNA B. Neither of the two daughter cells would be radioactive C. All four bases of the DNA would be radioactive D. Radioactive Thymine would pair with nonradioactive guanine E. DNA in both daughter cells would be radioactive. - correct answer E. DNA in both cells would be radioactive - This is true because one strand comes from the parent, and the other is the newly replicated one, meaning that both daughter cells will be radioactive. The polymerization of DNA, a phosphodeister bond is formed between a phosphate group of the nucleotide being added and ------ of the last nucleotide in the polymer. A. The 5' phosphate B. Carbon 6 C. The 3' OH D. a nitrogen form the nitrogen containing base - correct answer C. The 3' OH - This is true because the DNA Phosphodeister can only build upon the 3' end. DNA contains the template needed to copy itself, but it has no cellular activity in cells. What catalyzes the formation of phosphodeister between adjacent nucleotides in the DNA polymer being formed? A. topoisomerase B. DNA Ploymerase