Question

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). Which two classes of DNA do these different samples represent?a. RNA primers and mitochondrial DNA

b. Okazaki fragments and RNA primers
c. leading strands and Okazaki fragments
d. leading strands and RNA primers

Answer 1

Leading strands and Okazaki fragments.

Step-by-step explanation:

DNA shows the semi conservative mode of DNA replication in which the the DNA has one parental strand and one newly synthesized strand. Messelson and Sthal explains the semi conservative mode of the DNA replication.

The DNA also shows the semi discontinuous mode of replication. This means the one strand shows continuous synthesis containing large number of nucleotides. The other strand shows the synthesis in small fragments known as okazaki fragments.

Thus, the correct answer is option (c).