<prompt> If a completely radioactive double stranded DNA molecule undergoes two rounds of replication in a solution free of radioactive label. What is the radioactivity status of the resulting four double stranded DNA molecules50 of the DNA molecules have no radioactivity2 DNA molecules have radioactivity in both strandsI DNA molecule has radioactivity in both strandsAll 4 DNA molecules have radioactivity  <response>: DNA replication is semi conservative. Thus 2 DNA molecules have one strand with radioactivity and other 2 DNA molecules have no radioactivity. 