An E. coli cell with light DNA is incubated i | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The generation time of $E. coli$ is $20$ minutes.After $60$ minutes, the number of generations $(n)$ = $60 / 20 = 3$.Initially, there is $1$ molec

Vedclass · Accepted Answer

$25$

Vedclass · Answer

(B) The generation time of $E. coli$ is $20$ minutes.After $60$ minutes, the number of generations $(n)$ = $60 / 20 = 3$.Initially, there is $1$ molecule of light $DNA$ $(^{14}N-^{14}N)$.After $1$ generation: $2$ molecules ($1$ hybrid, $1$ light is not possible, both become hybrid $^{14}N-^{15}N$).Actually, in semi-conservative replication, the original strands remain as templates.After $n$ generations, the total number of $DNA$ molecules = $2^n = 2^3 = 8$.The number of $DNA$ molecules containing original light strands = $2$ (since only the two original strands from the parent cell will remain as light templates).Percentage of light $DNA$ = $(	ext{Number of light } DNA / 	ext{Total } DNA) 	imes 100 = (2 / 8) 	imes 100 = 25 \%$.

An $E. coli$ cell with light $DNA$ is incubated in a culture medium containing a heavy isotope of nitrogen $(^{15}N)$. After $60$ minutes, find out the percentage of light $DNA$. (in $\%$)

Similar Questions

Taylor and his colleagues proved that $DNA$ in chromosomes also replicates semi-conservatively. Which organism did they use for this experiment?

Okazaki fragments are synthesised on

What is the mode of $DNA$ replication in $E. coli$?

$A$ bacterium containing fully radioactive $DNA$ is allowed to replicate in a non-radioactive medium for two generations. What percentage of bacteria should contain radioactive $DNA$ (in $\%$)?

$^{15}N$ labeled $E. coli$ is allowed to grow in a $^{14}N$ medium. The two strands of the $DNA$ molecule of the first generation bacteria have:

Vedclass Test Series

Exam Paper Generator

Online Exam Module