DNA polymerase have:
**Core Concept**
DNA polymerase is an enzyme responsible for replicating DNA by adding nucleotides to a growing DNA strand. This process is crucial for DNA replication and repair. The enzyme has a proofreading function to ensure the accuracy of the newly synthesized DNA.
**Why the Correct Answer is Right**
DNA polymerase has a 3' to 5' exonuclease proofreading activity, which allows it to remove incorrect nucleotides from the growing DNA strand. This process involves the enzyme's ability to hydrolyze the phosphodiester bond between the incorrect nucleotide and the DNA strand. The 3' to 5' exonuclease activity is essential for maintaining the accuracy of DNA replication and repair.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as DNA polymerase does not have a 5' to 3' exonuclease activity, which is characteristic of other enzymes such as RNase H.
**Option B:** This option is incorrect as DNA polymerase does not have a 5' to 3' endonuclease activity, which is responsible for cleaving DNA at specific sites.
**Clinical Pearl / High-Yield Fact**
DNA polymerase's proofreading function is essential for maintaining the integrity of the genetic material. A defect in this function can lead to genetic mutations and diseases such as cancer.
**Correct Answer: C. 3' to 5' exonuclease activity.**