DNA Replication: The Initiation of DNA Synthesis

What is the starting point for DNA synthesis during DNA replication?

a. DNA primers
b. RNA primers
c. Random primers
d. Okazaki fragments

Answer:

The initiation of DNA synthesis during DNA replication begins with b. RNA primers.

DNA synthesis in DNA replication is initiated from RNA primers. These primers provide a starting point, allowing DNA polymerase to add DNA nucleotides. After synthesis, RNA primers are replaced with DNA nucleotides and gaps between Okazaki fragments are sealed by DNA ligase.

The initiation of DNA synthesis during DNA replication begins with the use of RNA primers. These primers are essential in providing a starting point for DNA synthesis. The enzyme DNA polymerase adds DNA nucleotides to the RNA primers, leading to the formation of new DNA strands.

During DNA replication, one strand of the DNA, known as the leading strand, is synthesized continuously in the direction of the replication fork. The other strand, known as the lagging strand, is synthesized discontinuously in short stretches termed Okazaki fragments. Each Okazaki fragment starts with an RNA primer.

Once DNA synthesis is complete, another enzyme, DNA polymerase I, removes the RNA primers and replaces them with DNA nucleotides. Finally, the gaps between the Okazaki fragments are sealed by an enzyme called DNA ligase, resulting in a continuous DNA strand.