Question

The enzymes responsible for adding nucleotides to the exposed DNA template bases are

Select one:
a. None of the above
b. DNA polymerases.
c. replicases.
d. helicases.

Answer 1

DNA polymerases are responsible for adding nucleotides to the growing DNA chain during replication. They require an existing 3' end to extend from and possess proofreading abilities to maintain replication accuracy.

Step-by-step explanation:

The enzymes responsible for adding nucleotides to the exposed DNA template bases are DNA polymerases. During the process of DNA replication, DNA polymerases catalyze the addition of nucleotide triphosphates to the 3' end of the nascent (newly forming) DNA strand, which is complementary to the DNA template.

DNA helicase is responsible for unwinding the DNA double helix by breaking the hydrogen bonds between the complementary bases, allowing the polymerases access to the individual strands. DNA ligase plays a crucial role in joining Okazaki fragments on the lagging strand, while primase synthesizes short RNA primers to provide a starting point for DNA polymerases to begin synthesis.

Proofreading is another important function of DNA polymerases, helping to ensure that the replication process is accurate by correcting errors that might occur during the synthesis of the new DNA strand.