AP BIOLOGY

Detailed explanation-1: -EXPLANATION: DNA polymerase is most active in S phase . The most important event occurring in S phase is the replication of DNA and DNA polymerase is responsible for DNA replication. Thus its activity is maximum during S phase.

Detailed explanation-2: -It occurs in the synthetic phase of the cell cycle. The DNA replicates using DNA polymerase and various other enzymes. So, the activity of the polymerase can be seen at the highest in this stage only.

Detailed explanation-3: -M phase (answer choice e) is mitosis. During this stage, the cell proceeds through the process of separating the chromosomes into daughter cells. DNA polymerase is not active during this stage, as the chromosomes have already replicated prior to the cell entering mitosis.

Detailed explanation-4: -Amongst the array of proteins at the replication fork, DNA polymerases are central to the process of replication. These important enzymes can only add new nucleoside triphosphates onto an existing piece of DNA or RNA; they cannot synthesize DNA de novo (from scratch), for a given template.

Detailed explanation-5: -DNA replication takes place in S phase of interphase. DNA polymerase is responsible for DNA replication. Thus its activity will be maximum during S phase.