Question

DNA replication in bacteria occurs

• A. During S-phase
• B. Within nucleolus
• C. Prior to fission
• D. Just before transcription

Answer 1

The Correct Option is C

DNA replication in bacteria occurs prior to fission. Here's the detailed explanation and reasoning:

1. Understanding Binary Fission in Bacteria:
   • Bacteria are prokaryotes, and their method of reproduction is a simple process known as binary fission.
   • In binary fission, the bacterial cell divides into two identical daughter cells.
   • Before a bacterial cell divides, it needs to replicate its DNA so each daughter cell receives a copy of the genetic material.
2. Timing of DNA Replication:
   • In bacterial cells, there are no distinct cell cycle phases (like G1, S, G2, and M phases found in eukaryotes).
   • However, DNA replication must occur before the cell physically divides through fission.
   • Therefore, DNA replication in bacteria occurs prior to fission to ensure that both daughter cells have identical genetic material.
3. Why Other Options Are Incorrect:
   • During S-phase: This phase is applicable to eukaryotic cells, not bacteria.
   • Within nucleolus: Bacteria lack a nucleus and nucleolus; they have a nucleoid instead.
   • Just before transcription: Transcription is independent of DNA replication; it can occur at various phases unrelated to replication directly before binary fission.
4. Conclusion: The correct answer is prior to fission, as this is when DNA replication must be completed for successful cell division in bacteria.