THE MOLECULAR BASIS OF INHERITANCE
DNA REPLICATION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
synthesizes the RNA primer, initiates DNA synthesis and the lagging strand
|
|
|
synthesizes the leading strand, filling DNA gaps after removal of primer
|
|
|
Repair DNA
|
|
|
replicate mitochondrial DNA
|
Detailed explanation-1: -DNA polymerase plays a central role in the base excision DNA repair pathway that cleanses the genome of apurinic/apyrimidinic (AP) sites. AP sites arise in DNA from spontaneous base loss and DNA damage-specific glycosylases that hydrolyze the N-glycosidic bond between the deoxyribose and damaged base.
Detailed explanation-2: -Since its discovery and purification in 1971, DNA polymerase ß (Pol ß) is one of the most well-studied DNA polymerases. Pol ß is a key enzyme in the base excision repair (BER) pathway that functions in gap filling DNA synthesis subsequent to the excision of damaged DNA bases.
Detailed explanation-3: -Nucleotide excision-repair uses DNA polymerases delta or epsilon to resynthesize the bases removed during repair of pyrimidine dimers and other bulky adducts in DNA. Similarly, mismatch-repair of replication errors appears to involve DNA polymerases delta or epsilon.
Detailed explanation-4: -DNA polymerase beta contributes two enzymatic activities: DNA synthesis and deoxyribose-phosphate removal through nucleotidyl transferase and lyase mechanisms, respectively.
Detailed explanation-5: -In addition to their roles in chromosomal DNA replication, DNA polymerases participate in numerous DNA repair pathways, including double-strand break repair (61–63), mismatch repair (3, 64, 65), base excision repair (3, 66, 67), and nucleotide excision repair (3).