Question

Among eukaryotes, replication of DNA takes place in:

• A. S phase
• B. G₁ phase
• C. G₂ phase
• D. M Phase

Answer 1

The Correct Option is A

In eukaryotic cells, the cell cycle consists of several distinct phases: G₁ phase, S phase, G₂ phase, and M phase. Each phase has a specific role in preparing the cell for division.

S Phase (Synthesis phase) is the part of the cell cycle in which DNA replication takes place. During this phase, each chromosome is duplicated to ensure that the two daughter cells will each receive an identical set of chromosomes.

Other phases:

• G₁ Phase is a period of cell growth before DNA synthesis begins. The cell increases in size and synthesizes proteins and organelles.
• G₂ Phase is the period after DNA synthesis where the cell continues to grow and prepares for mitosis. This phase involves the production of proteins and organelles and further cell growth.
• M Phase (Mitosis) is the phase where cell division occurs. It involves the distribution of identical sets of chromosomes into two daughter nuclei.

Hence, in eukaryotes, DNA replication takes place during the S phase.