DNA Content in Binary Fission Stages

Steps:

• Identify starting cell V in G1 phase with unreplicated DNA (1 unit).
• Note cell W before S phase, still with 1 unit of DNA.
• Recognize cell X after DNA replication in G2 phase, with 2 units.
• Observe cells Y and Z as daughter cells post-division, each with 1 unit after cytokinesis.

Why C is correct:

• Matches binary fission where DNA doubles from 1 to 2 during S phase before splitting equally into two 1-unit cells.

Why the others are wrong:

• A: Shows premature doubling in later cells without replication sequence.
• B: Places doubling too early, before S phase.
• D: Starts with 2 units, inconsistent with G1 starting point.

Final answer: C