NEET 2022 Biology question
Ten E.coli cells with N - dsDNA are incubated in medium containing N nucleotide. After 60 minutes, how many E.coli cells will have DNA totally free from N?
Answer: (D)
Solution
60 min = 3 generations (20 min each): 80 cells, of which 20 carry one N strand, so 60 cells are free of N.