E Coli Cells Grown on ¹⁵N Medium Are Transferred to ¹⁴N

Multiple Choice

E. coli cells grown on ¹⁵N medium are transferred to ¹⁴N medium and allowed to grow for two more generations (two rounds of DNA replication) . DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment?

A) one high-density and one low-density band
B) one intermediate-density band
C) one high-density and one intermediate-density band
D) one low-density and one intermediate-density band