What are Okazaki fragments?

What are Okazaki fragments?

• A. Large fragments on the leading strand.
• B. Proteins that bind DNA.
• C. Segments of RNA used as primers.
• D. Smaller DNA fragments synthesized on the lagging strand during replication.

Answer: (D)

Okazaki fragments are the short DNA pieces made on the lagging strand during DNA replication. The DNA polymerase can only synthesize in the 5' to 3' direction, so on the strand that runs opposite the fork, synthesis occurs in small, separate segments rather than one continuous stretch. Each fragment begins with an RNA primer laid down by primase, providing a starting point for DNA polymerase to extend a section of DNA. Later, the fragments are connected by DNA ligase to form a continuous strand. This contrasts with the leading strand, which is synthesized continuously toward the fork. RNA primers themselves are not the fragments; they mark the start of each fragment’s synthesis.

Okazaki fragments are the short DNA pieces made on the lagging strand during DNA replication. The DNA polymerase can only synthesize in the 5' to 3' direction, so on the strand that runs opposite the fork, synthesis occurs in small, separate segments rather than one continuous stretch. Each fragment begins with an RNA primer laid down by primase, providing a starting point for DNA polymerase to extend a section of DNA. Later, the fragments are connected by DNA ligase to form a continuous strand. This contrasts with the leading strand, which is synthesized continuously toward the fork. RNA primers themselves are not the fragments; they mark the start of each fragment’s synthesis.