2.3.8 Binary Fission

Steps of Binary Fission:

1. Replication of DNA:

• The circular DNA molecule is replicated, producing two identical copies.
• Plasmids (smaller, circular DNA molecules) also replicate, but the number of plasmids may vary between the daughter cells.

2. Cell Growth:

• The cell membrane grows between the two DNA molecules, increasing the size of the cell.
• The membrane begins to pinch inwards, dividing the cytoplasm into two sections.

3. Formation of New Cell Walls:

• A new cell wall forms between the two sets of DNA, completely dividing the cell.
• This results in two identical daughter cells, each containing:
• One copy of the circular DNA.
• A variable number of plasmids.

Key Points about Binary Fission:

• It is a fast and efficient process, allowing bacteria to reproduce rapidly under ideal conditions.
• Daughter cells are genetically identical except for potential differences in the number of plasmids.

Viruses and Cell Division:

• Viruses are non-living and do not undergo cell division.
• Instead, they replicate by infecting a host cell:
  • Viral nucleic acids are injected into the host cell.
  • The host cell's machinery replicates the viral genetic material and produces new virus particles.