Question

In: Biology

A bacteria culture is grown for many generations in a medium in which the only available...

A bacteria culture is grown for many generations in a medium in which the only available nitrogen is the heavy isotope (15N). The culture is then switched to a medium containing only 14N for TWO generation of growth; it is then recultured to a 15N-containing medium for ONE final generation of growth. The DNA from these bacteria is isolated and centrifuged to equilibrium in a CsCl density gradient.

(a) Determine the proportion of 15N15N, 15N14N, and 14N14N DNA if the replication is following the semiconservative mode. Show your work to gain maximum mark.

(b) Determine the proportion of 15N15N, 15N14N, and 14N14N DNA if the replication is following the conservative mode. Show your work to gain maximum mark.

Note: You may hand-sketch the drawing in a piece of blank paper, scan or take a photo of your drawing, and attached it in your Word document.

Solutions

Expert Solution

DNA replication - copying of DNA is called DNA replication.

The mode of dna replication is semiconservative in organism but the hypothetically may be conservative and dispersive .

semiconservative -If after replication in DNA one strand is conserve and one strand new formed in one DNA molecule then this is called semi conservative mode of replication.

conservative - while if after replication one dna have both strand new and one dna both stand parental it means both are conserve . this is called conservative mode of replication.

from the question the data given , the calculation for both mode of replication that is semiconservative and conservative given below-


Related Solutions

A. In a Meselson-Stahl type experiment, bacterial cells grown in 15N medium for many generations were...
A. In a Meselson-Stahl type experiment, bacterial cells grown in 15N medium for many generations were washed and then allowed to grow in 14N medium. DNA was extracted just after transfer (0 generation) and then after 1 and 2 generations. All these samples were analyzed by CsCl gradient centrifugation. From DNA isolated from generations 0, 1 and 2 show. B.Position of bands in the centrifuge tubes C. 14N and 15N labelled DNA strands Answer both questions for each mode of...
Which method is used to culture viruses that attack only bacteria?     I. a continuous or...
Which method is used to culture viruses that attack only bacteria?     I. a continuous or immortal cell line II. a primary cell line Group of answer choices Neither I or II Only I Only II Both I and II
3. Assume that a bacterial culture is grown on medium containing radioactive thymine until essentially all...
3. Assume that a bacterial culture is grown on medium containing radioactive thymine until essentially all of the thymine in the DNA is radioactive. Then the bacteria with labeled T were washed and transferred to a medium containing nonradioactive T for one round of replication. Given the four double stranded sequences below, which one is likely to represent the replicated double stranded structure? Note: A,C,T,G represent typical nucleotides, and 3T represents labeled T.) 1 2 3 4 One strand A...
Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow...
Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevated NaCl level. Escherichia Coli is also inoculated and after incubation Escherichia Coli did not grow and a pH indicator causes a yellow halo to surround the growth of Staphylococcus aureus. This type of medium would be referred to as a(n) ____________ based on this information.
Which of the following types of bacteria can survive and grown in the presence of oxygen....
Which of the following types of bacteria can survive and grown in the presence of oxygen. CHECK ALL THAT APPLY Aerotolerant Microaerophiles Facultative Anaerobes Obligate Anaerobes Obligate Aerobes
Tissue culture medium is the “soup” that cells are grown in. Briefly describe its composition and best conditions for cell culturing.
Tissue culture medium is the “soup” that cells are grown in. Briefly describe its composition and best conditions for cell culturing. (Hint: List the names and write down for what purpose we use them)?
Is the culture medium: Phenyl ethyl Alcohol ( PEA) Selective Differential Bacteria Gram stain Growth Changes...
Is the culture medium: Phenyl ethyl Alcohol ( PEA) Selective Differential Bacteria Gram stain Growth Changes in the culture medium or bacteria Escherichia coli Negative no Pseudomonas fluorescens negative no Enterobacter aerogenes negative no Alcaligenes faecalis Negative no Micrococcus luteus Negative yes No changes Staphylococcus epidermidis positive yes No changes Enterococcus faecalis positive Yes No changes Bacillus cereus positive Yes No changes Only 1 Only 2 Both 1 and 2 Neither 1 or 2 Syprogyra is ________. A eukaryotic organism...
* Which of these are routinely used to obtain a pure culture of bacteria? a. swan...
* Which of these are routinely used to obtain a pure culture of bacteria? a. swan necked flasks b. agar streak plates c. dilution plates d. microscopes * The cells of all species of Bacteria and Archaea are very small, and: a. must be stained before they can be seen using light microscopy b. can only be seen using electron microscopy c. can only be seen if they are first Gram stained d. none of the above * Prokaryotes evolved...
a) Suppose that 650 bacteria are present initially in a culture. If the number of bacteria...
a) Suppose that 650 bacteria are present initially in a culture. If the number of bacteria triple every 5 hours, how long is it until there are 50,000 bacteria in the culture? b) The half-life of C14 is 5730 years. If a fossilized leaf contains 42% of its normal amount of C14, how old is the fossil? c) HOw long does it take for an investment to double in value if it is invested at 3.6% compounded quarterly?
1. There are 300 bacteria in a culture, and the number of bacteria quadruples every 5...
1. There are 300 bacteria in a culture, and the number of bacteria quadruples every 5 hours. A. Write a function, N, that gives the number of bacteria t hours from now. B. How many will there be in 20 hours? C. In how many hours will there be 2,000 bacteria? 2. The population of Johnsonville was 900 in 1880 and is known to double every 20 years. a. Write a function, P, that gives the population y years after...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT