Answer:
Explanation:
1. In the initial sample which is immediately removed after addition of radioactive isotope of phosphorus ( 3232P), hence there is no incorporation of 3232P into the DNA because replication in the medium containing 3232P has not yet occurred.
2. After one round of replication in radioactive isotope of phosphorus ( 3232P) containing medium, here only one newly synthesized strand of DNA molecule will contain 3232P, while the other strand will not contain any radioactive isotope of phosphorus ( 3232P), because DNA replication occurs in semi-conservative way.
3. After two rounds of replication in medium which contains radioactive isotope of phosphorus ( 3232P), here 50% of the DNA molecules will have radioactive isotope 3232P in both strands, while the rest 50% will contain 3232P in only one strand and nonradioactive phosphorous in the other strand.