Question

What is the relationship between DNA replication and the S phase of the cell cycle?

Short answer

DNA (Deoxyribonucleic acid) replication occurs in the synthesis (S) phase of the cell cycle. Thus, the DNA doubles before the cell enter mitosis, where the cell divides to form two daughter cells.

Step-by-step solution

DNA Replication

DNA is a molecule that carries genetic information. The information present in the DNA is transmitted from one generation to the next. Thus, DNA is a hereditary molecule. To preserve genetic information and pass it to the daughter cells necessitates DNA molecule replication.

DNA replication occurs in the cell nucleus, where two daughter DNA molecules are synthesized that are exact copies of the parent cell. Thus, replication leads to the doubling of DNA molecules.

Cell cycle

A series of events occur in the cell that prepares it for cell division.During these events, the cell enlarges, synthesizes proteins, organelles, and other molecules, and doubles the DNA molecule. These events are referred to as the cell cycle.

The cell cycle is mainly divided into two phases. The phase in which the cell enlarges and grows for cell division is called interphase, and the phase where the cell divides is called the mitotic phase.

Interphase is a long phase as it is further divided into three stages; G1, S, and G2. The cell grows in the G1 phase. It enlarges because of the volume of the contents of the cell increases. DNA synthesis occurs in the synthesis (S) phase of the cell cycle.

In the G2 phase, the cell prepares to divide in the mitotic phase. Thus, cell organelles and proteins required for mitosis are produced in the G2 phase. Finally, the cell enters the mitotic phase for cell division.

Relationship between DNA replication and S-phase

S phase is the stage of the cell cycle where DNA replication takes place. This means the S phase of the cell cycle is responsible for DNA replication. Thus, before the cell enters mitosis or meiosis, the genetic content of the cell is doubled.

Thus, the S phase of the cell cycle ensures the cell has enough DNA content so that when the cell divides in mitosis, the genetic information divides equally into the two daughter cells.