Question

upon examination, a cell is found to have twice as much dna as the normal diploid state but is no longer in the process of replicating the dna. all of the dna is found within a single nucleus. which phase of the cell cycle is this cell in?
a) m
b) s
c) g₁
d) g₂
e) cytokinesis

Explanation:

• M phase: In the M phase (mitosis or meiosis), the cell is actively dividing. DNA replication has already occurred before M phase, but during M phase, the nucleus is not in a single - intact state throughout (e.g., during prophase, the nuclear envelope breaks down).
• S phase: In the S phase (synthesis phase), DNA is being replicated. The problem states that the cell is no longer in the process of replicating DNA.
• G₁ phase: In the G₁ phase, the cell has a diploid amount of DNA (\(2n\)). It is the phase before DNA replication.
• G₂ phase: In the G₂ phase, DNA replication (which occurs in S phase) is complete. The cell has twice the amount of DNA (\(4n\)) compared to the diploid state (\(2n\)) before S phase. The DNA is within a single nucleus at this stage.
• Cytokinesis: Cytokinesis is the process of dividing the cytoplasm. It occurs after nuclear division (in M phase). At this stage, the DNA content per nucleus is either \(2n\) (after mitosis) or \(n\) (after meiosis), and the focus is on cytoplasmic division rather than having twice the diploid DNA in a single nucleus.

Answer:

d) \(G_{2}\)