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.

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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-

gladiator answered 1 year ago

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