Question

eselson and Stahl relied on equilibrium density gradient centrifugation to resolve the DNA containing 14N from the DNA containing 15N.They started off with DNA in media containing the heavy isotope, then switched to media containing the lighter isotope and allowed DNA replication to take place. Under semiconservative model of DNA replication, after THREE rounds of replication, how many bands of DNA would you see and which band would contain more DNA molecules

Answer 1

The correct answer would be - two bands ( one intermediate, and one light)- the light band contains more DNA molecules.

Step-by-step explanation:

After the switching to the lighter isotope by the second round of replication where light strands are used as template strands, produces the light band of 14N.

After three rounds of semiconservative replication, where template strand contains both heavy and new formed light bands or nitrogen and produces so in a Density gradient, there will be 2 bands one light band and the other intermediate band.