Binary Fission

• Binary Fission


  Prokaryotic cells can reproduce using a type of simple cell division called binary fission
• Prokaryotic Cells Replicate by Binary Fission


  1. The circular DNA and plasmid(s) replicate

  2. The cell gets bigger and the circular DNA strands move to opposite 'poles' of the cell

  3. The cytoplasm begins to divide and new cell walls begin to form

  4. The cytoplasm divides and two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but can have a variable number of copies of the plasmid(s)
• Bacteria can divide very quickly if given the right conditions (e.g. a warm environment and lots of nutrients)
• Some bacteria, such as E. coli, can take as little as 20 minutes to replicate in the right environment
• If conditions become unfavourable, the cells will stop dividing and eventually begin to die
• Mean division time


  The average amount of time it takes for one bacterial cell to divide into two
• Calculating the Number of Bacteria in a Population


  1. Divide the total time that the bacteria are producing cells by the mean division time to get the number of divisions

  2. Multiply 2 by itself for the number of divisions to find the number of cells
• Each cell divides to produce 2 cells, so the number of cells increases by a power of 2 for each division