Question

alllll them please all

To MOST readily demonstrate transformation of bacteria in the laboratory one could extract DNA from: A) his cells and add the DNA to his cells, then grow the cells on plates with histidine B) hist cells and add the DNA to his cells, then grow the cells on plates without histidine C) lac" cells and add the DNA to lact cells, then grow the cells on plates without histidine D) amp cells and add the DNA to amp' cells, then grow the cells on plates with ampicillin E) lac' cells and add the DNA to lac cells, then grow the cells on plates without lactose

Answer 1

Question 1: Answer is option B.

His+ cells have the synthetic gene of Histidine. Thus, additional of His+ cell DNA to his- cells will generate recombinant his- cells having histidine synthetic gene. Thus, these cells are able to grow in Histidine without medium.

Question 2: Answer is option C.

Due to binding of allolactose to the repressor monomers, repressor proteins can't form the tetrameric structure. But if allolactose can't able to bind the repressor then tetrameric structure will form and repressor protein remains bound to the operator region even in absence and presence of allolactose.

Question 3: Answer is option B.

DNA is negatively charged and histone proteins are mostly positively charged. Thus, DNA-histone interaction occurs. If histone's positive charge is shielded by phosphate then the interaction between DNA and histone will not occur due to repulsion of negative charges.

Question 4: Answer is option D.

Both EcoRI and HindIII will cut the DNA once generating two fragments each.

Question 5: Answer is option B.

By Sanger's method DNA sequencing is possible.

Question 6: Answer is option D.

Expression of lac operon genes don't occur if glucose is present in the medium. At that time lac repressor inhibits the expression of lac operon genes. But due to mutation of operator region this inhibition is inhibited. So, lac operon genes will also express even in presence and/or absence of glucose and lactose.

Question 7: Answer is option B.

BER occurs if there is any apurinic site present.

Question 8: Answer is option C