Question

in humans, protein 53 (p53) is a tumor suppressant protein encoded on the p53 gene, which has been mapped to the short arm of chromosome 17. one role of this protein is to facilitate the repair of damaged dna. in which part of the cell cycle does the p53 gene have the most active role?

Explanation:

The \(S\) phase (synthesis phase) is when DNA replication occurs. Since the \(p53\) protein facilitates the repair of damaged DNA, it would be most active during the phase when DNA is being replicated (and thus when DNA damage could be most critical for proper cell division and preventing mutations). In the \(G_1\) phase, the cell grows and prepares for DNA synthesis. In \(G_2\), it prepares for mitosis. In \(M\) (mitosis), the cell divides. But the key for \(p53\)’s role in DNA repair (related to DNA integrity during replication) is the \(S\) phase.

Answer:

S