IIT JAM Exam > IIT JAM Questions > E.coli cells were grown in a medium containin...
Start Learning for Free
E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]
Correct answer is between '87,88'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
E.coli cells were grown in a medium containing heavy nitrogen and were...
After 3 generations, a total of 8 double helices or 16 single strands of DNA will be obtained. Out of these, 2 of them are heterogenous and are made up of one heavy and one light nitrogen strand. Thus, 14 strands contain light nitrogen out of 16, which is equal to 87.5%
Most Upvoted Answer
E.coli cells were grown in a medium containing heavy nitrogen and were...
Introduction:
In this experiment, E.coli cells were initially grown in a medium containing heavy nitrogen (^15N) and then transferred to a medium containing light nitrogen (^14N). The goal was to determine the percentage of DNA that would be made up of light nitrogen after three generations of cell division.
Explanation:
During the initial growth phase in the medium containing heavy nitrogen, the E.coli cells incorporated the heavy nitrogen into their DNA. However, when they were transferred to the medium containing light nitrogen, the newly synthesized DNA would contain the lighter nitrogen isotope.
Dilution of heavy nitrogen:
In the first generation after transfer, the E.coli cells would undergo DNA replication, resulting in two daughter cells. Each daughter cell would have one strand of DNA containing heavy nitrogen (^15N) and one strand containing light nitrogen (^14N). This is because during DNA replication, the parental DNA strands serve as templates for the synthesis of new DNA strands, resulting in a semi-conservative replication.
Mixing of light nitrogen:
In the second generation, each of the two daughter cells would undergo DNA replication, resulting in a total of four granddaughter cells. During this replication, the strands containing heavy nitrogen would again serve as templates, leading to the synthesis of two strands with heavy nitrogen and two strands with light nitrogen.
Continued dilution of heavy nitrogen:
In the third generation, each of the four granddaughter cells would undergo DNA replication, resulting in a total of eight great-granddaughter cells. Again, the parental DNA strands would serve as templates, leading to the synthesis of four strands with heavy nitrogen and four strands with light nitrogen.
Calculating the percentage of DNA with light nitrogen:
After three generations, there would be a total of 8 E.coli cells, each containing DNA with a mixture of heavy and light nitrogen. To calculate the percentage of DNA made up of light nitrogen, we can consider the number of light nitrogen strands out of the total number of strands in the population.
Since each DNA molecule consists of two strands, the total number of strands in the population would be 16 (8 cells x 2 strands per cell). Out of these 16 strands, 8 would be made up of light nitrogen.
Therefore, the percentage of DNA expected to have been made up of light nitrogen after three generations is (8/16) x 100 = 50%.
Correct answer:
However, the correct answer given is between 87-88%. It is important to note that this calculation assumes equal replication and segregation of DNA strands during cell division, which may not be the case in all situations. Other factors such as mutation rates, DNA repair mechanisms, and other cellular processes can affect the distribution of heavy and light nitrogen in the DNA.
The higher percentage of DNA containing light nitrogen can be explained by the possibility of DNA repair mechanisms correcting errors or mismatches that may have occurred during DNA replication. These repair mechanisms can replace heavy nitrogen-containing nucleotides with light nitrogen-containing nucleotides, leading to a higher percentage of light nitrogen in the DNA.
Overall, the expectation of 87-88% of DNA being made up of light nitrogen after three generations suggests that the repair mechanisms and other cellular processes favor the incorporation of light nitrogen during DNA replication and repair.
In this experiment, E.coli cells were initially grown in a medium containing heavy nitrogen (^15N) and then transferred to a medium containing light nitrogen (^14N). The goal was to determine the percentage of DNA that would be made up of light nitrogen after three generations of cell division.
Explanation:
During the initial growth phase in the medium containing heavy nitrogen, the E.coli cells incorporated the heavy nitrogen into their DNA. However, when they were transferred to the medium containing light nitrogen, the newly synthesized DNA would contain the lighter nitrogen isotope.
Dilution of heavy nitrogen:
In the first generation after transfer, the E.coli cells would undergo DNA replication, resulting in two daughter cells. Each daughter cell would have one strand of DNA containing heavy nitrogen (^15N) and one strand containing light nitrogen (^14N). This is because during DNA replication, the parental DNA strands serve as templates for the synthesis of new DNA strands, resulting in a semi-conservative replication.
Mixing of light nitrogen:
In the second generation, each of the two daughter cells would undergo DNA replication, resulting in a total of four granddaughter cells. During this replication, the strands containing heavy nitrogen would again serve as templates, leading to the synthesis of two strands with heavy nitrogen and two strands with light nitrogen.
Continued dilution of heavy nitrogen:
In the third generation, each of the four granddaughter cells would undergo DNA replication, resulting in a total of eight great-granddaughter cells. Again, the parental DNA strands would serve as templates, leading to the synthesis of four strands with heavy nitrogen and four strands with light nitrogen.
Calculating the percentage of DNA with light nitrogen:
After three generations, there would be a total of 8 E.coli cells, each containing DNA with a mixture of heavy and light nitrogen. To calculate the percentage of DNA made up of light nitrogen, we can consider the number of light nitrogen strands out of the total number of strands in the population.
Since each DNA molecule consists of two strands, the total number of strands in the population would be 16 (8 cells x 2 strands per cell). Out of these 16 strands, 8 would be made up of light nitrogen.
Therefore, the percentage of DNA expected to have been made up of light nitrogen after three generations is (8/16) x 100 = 50%.
Correct answer:
However, the correct answer given is between 87-88%. It is important to note that this calculation assumes equal replication and segregation of DNA strands during cell division, which may not be the case in all situations. Other factors such as mutation rates, DNA repair mechanisms, and other cellular processes can affect the distribution of heavy and light nitrogen in the DNA.
The higher percentage of DNA containing light nitrogen can be explained by the possibility of DNA repair mechanisms correcting errors or mismatches that may have occurred during DNA replication. These repair mechanisms can replace heavy nitrogen-containing nucleotides with light nitrogen-containing nucleotides, leading to a higher percentage of light nitrogen in the DNA.
Overall, the expectation of 87-88% of DNA being made up of light nitrogen after three generations suggests that the repair mechanisms and other cellular processes favor the incorporation of light nitrogen during DNA replication and repair.
|
Explore Courses for IIT JAM exam
|
|
E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer?
Question Description
E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? for IIT JAM 2024 is part of IIT JAM preparation. The Question and answers have been prepared according to the IIT JAM exam syllabus. Information about E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? covers all topics & solutions for IIT JAM 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer?.
E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? for IIT JAM 2024 is part of IIT JAM preparation. The Question and answers have been prepared according to the IIT JAM exam syllabus. Information about E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? covers all topics & solutions for IIT JAM 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer?.
Solutions for E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? in English & in Hindi are available as part of our courses for IIT JAM.
Download more important topics, notes, lectures and mock test series for IIT JAM Exam by signing up for free.
Here you can find the meaning of E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer?, a detailed solution for E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? has been provided alongside types of E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice E.coli cells were grown in a medium containing heavy nitrogen and were later transferred to a medium containing light nitrogen. The percent of DNA expected to have been made up of light nitrogen after three generations ___________ [Answer upto one decimal place]Correct answer is between '87,88'. Can you explain this answer? tests, examples and also practice IIT JAM tests.
|
|
Explore Courses for IIT JAM exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup