Question

(b) “DNA replication is continuous and discontinuous on the two strands within the replication fork.” Explain with the help of a schematic representation.

Hint:

Remember, the key difference lies in the directionality of synthesis: the leading strand is synthesized in one continuous stretch, while the lagging strand involves multiple short fragments.

Answer 1

DNA replication is semi-conservative, meaning parental strands act as templates for new complementary strands. Because DNA is antiparallel and DNA polymerase functions unidirectionally (5' to 3'), synthesis differs at the replication fork:\begin{itemize} \item Leading strand: Synthesized continuously 5' to 3', tracking the fork's movement. \item Lagging strand: Synthesized in short segments (Okazaki fragments) that DNA ligase subsequently joins.\end{itemize} Schematic Representation: \begin{figure}[H] \centering \includegraphics[width=0.7\linewidth]{Screenshot 2025-01-23 090112.png} % Replace 'path_to_image.png' with the actual schematic representation file path \caption{Schematic diagram of DNA replication showing the continuous synthesis of the leading strand and the discontinuous synthesis of the lagging strand with Okazaki fragments.} \label{fig:dna_replication}\end{figure}% Quick tip