Okazaki segment are formed during.a)transduction b)transcription c)rep...
The right answer is c)replication Later on these fragments are joined by DNA ligase...Hope u get it..
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Okazaki segment are formed during.a)transduction b)transcription c)rep...
Okazaki segments are formed during DNA replication.
Introduction
During DNA replication, the two strands of the double helix are unwound, and each strand serves as a template for the synthesis of a new complementary strand. However, DNA polymerase can only synthesize new DNA in one direction, known as the 5' to 3' direction. This creates a problem during replication of the lagging strand, which is synthesized in the opposite direction. To overcome this issue, Okazaki segments are formed.
DNA Replication
DNA replication is a process in which a cell makes an identical copy of its DNA. It occurs during the S phase of the cell cycle and is crucial for the accurate transmission of genetic information from one generation to the next. DNA replication involves several enzymes and proteins, including DNA polymerase, helicase, primase, and ligase.
Okazaki Segments
1. Formation: Okazaki segments are short fragments of DNA that are synthesized discontinuously on the lagging strand during DNA replication. They are named after the Japanese scientist Reiji Okazaki, who first discovered them.
2. Lagging Strand: The lagging strand is replicated in short stretches, known as Okazaki fragments, because DNA polymerase can only synthesize DNA in the 5' to 3' direction.
3. Primase: Before DNA polymerase can begin synthesizing the lagging strand, an RNA primer is synthesized by an enzyme called primase. This primer provides a starting point for DNA polymerase to add nucleotides.
4. DNA Polymerase: DNA polymerase adds nucleotides to the RNA primer, synthesizing a short segment of DNA. Once it reaches the previously synthesized fragment, it detaches and moves further along the lagging strand.
5. Okazaki Fragment Length: The length of Okazaki fragments can vary depending on the organism and the specific region of DNA being replicated. In prokaryotes, the fragments are typically around 1,000 to 2,000 nucleotides long, whereas in eukaryotes, they are shorter, ranging from 100 to 200 nucleotides.
6. Joining: After the synthesis of Okazaki fragments, the RNA primers are removed, and the gaps between the fragments are filled with DNA by DNA polymerase. Finally, the fragments are ligated together by an enzyme called DNA ligase, resulting in a continuous lagging strand.
Conclusion
Okazaki segments are formed during DNA replication on the lagging strand. They are synthesized discontinuously in the opposite direction to the replication fork and are later joined together to create a continuous lagging strand. Understanding the formation of Okazaki segments is crucial for comprehending the process of DNA replication and the accurate transmission of genetic information.
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