You decide to repeat the meselson-stahl experiment, except this time you plan to grow the e coli cells on light 14n medium for many generations and then transfer them to heavy 15n medium and allow them to grow for 2 additional generations (2 rounds of dna replication). if the semiconservative model of dna replication is correct, what is the expected distribution of dna in the density gradient after one round of replication? a. a single band of intermediate density. b. a single band of light density. c. a single band of heavy density. d. one band of light density and one band of heavy density. e. one band of light density and one band of intermediate density.