DNA Replication: semiconservative replication
: each old strand is used to synthesize a new strand
Phosphorus is required to synthesize the deoxyribonucleoside triphosphates used in DNA replication. A geneticist grows some E. coli in a medium containing nonradioactive phosphorus for many generations. A sample of the bacteria is then transferred to a medium that contains a radioactive isotope of phosphorus (32P). Samples of the bacteria are removed immediately after the transfer and after one and two rounds of replication. Assume that newly synthesized DNA contains 32P and the original DNA contains nonradioactive phosphorus.
What will be the distribution of radioactivity in the DNA of the bacteria in each sample?
• One strand has 32P incorporated.
• 50% of the DNA molecules have 32P in one strand.
• No 32P incorporated into the DNA.
• 50% of the DNA molecules have 32P in both strands.
• Both strands have 32P incorporated.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Semiconservative Replication concept. You can view video lessons to learn Semiconservative Replication. Or if you need more Semiconservative Replication practice, you can also practice Semiconservative Replication practice problems.