Question
DNA is isolated from bacteria undergoing DNA replication. After heat treatment to disrupt H-bonds the DNA is centrifuged and it separates into two classes. One class of 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 types of DNA do the two classes most likely represent?
leading strands and fragments generated due to replication errors
Okazaki fragments and Origin of replication
lagging strands and Okazaki fragments
leading strands and Okazaki fragments
leading strands and fragments generated due to replication errors
Okazaki fragments and Origin of replication
lagging strands and Okazaki fragments
leading strands and Okazaki fragments
Answers
GPT-4o mini
The two classes of DNA in your scenario most likely represent **leading strands and Okazaki fragments**.
In bacterial DNA replication, the leading strand is synthesized continuously in the direction of the replication fork, resulting in a long, continuous DNA strand. In contrast, the lagging strand is synthesized discontinuously in short segments called Okazaki fragments due to the antiparallel nature of DNA strands. These fragments are typically a few hundred to a few thousand nucleotides long. Thus, the large molecules represent the leading strands, while the shorter segments represent the Okazaki fragments.
In bacterial DNA replication, the leading strand is synthesized continuously in the direction of the replication fork, resulting in a long, continuous DNA strand. In contrast, the lagging strand is synthesized discontinuously in short segments called Okazaki fragments due to the antiparallel nature of DNA strands. These fragments are typically a few hundred to a few thousand nucleotides long. Thus, the large molecules represent the leading strands, while the shorter segments represent the Okazaki fragments.