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Which of the following statements is INCORRECT regarding DNA replication?

A) FALSE: A short segment (~10 nucleotides) of DNA primer is required to enable DNA polymerase to extend the growing daughter strand.
B) Helicase is required to unwind the DNA
C) Single Stranded Binding Proteins prevent single strands of the parental DNA from reforming
D) DNA polymerase is firmly attached to the template via the assistance of Sliding Clamp while it synthesizes a new strand of DNA
E) Topoisomerase is required to relieve the torsional stress that develops ahead of the replication fork.

User JeromeFr
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Final answer:

The incorrect statement regarding DNA replication is that a DNA primer is needed for DNA polymerase to start synthesis, when in fact, an RNA primer synthesized by primase is required. DNA polymerase extends the new strand from the primer, and other enzymes like helicase, single-stranded binding proteins, and topoisomerase play crucial roles in this process.

Step-by-step explanation:

The statement that is INCORRECT regarding DNA replication is: A) FALSE: A short segment (~10 nucleotides) of DNA primer is required to enable DNA polymerase to extend the growing daughter strand. The correct sequence of events involves an RNA primer, not a DNA primer, which is synthesized by primase and is typically around 10-12 nucleotides long. This primer is required for DNA polymerase to initiate the synthesis of the new DNA strand because DNA polymerase can only add nucleotides to an existing strand; it cannot start synthesis de novo.

DNA replication involves various proteins and enzymes that play specific roles such as helicase which separates the DNA strands, single-stranded binding proteins that stabilize the single-stranded DNA, primase which synthesizes an RNA primer, DNA polymerase which extends the new DNA strand using this primer, and topoisomerase which relaxes supercoiling in the DNA ahead of the replication fork.

Important to note, topoisomerase actually prevents over-winding by causing temporary nicks in the DNA's phosphate backbone and later resealing it. Sliding clamp proteins maintain the association of DNA polymerase with the DNA template. Once the RNA primers are removed, DNA ligase helps to seal the nicks in the sugar-phosphate backbone, completing the replication process.

User Johv
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