Bacterial Division

• Bacteria are prokaryotes, their genetic information is not enclosed in a nucleus
• Binary fission


  The process where one bacterial cell splits into two bacterial cells
• Bacteria can carry out binary fission once every 20 minutes as long as they have enough nutrients and the temperature is suitable
• Calculating the number of bacteria after a given time

  1. Calculate the number of rounds of division

  2. Use the equation: Number of bacteria = 2^n, where n is the number of rounds of division
• The equation Number of bacteria = 2^n, where n is the number of rounds of division, is not given in the exam so it's important to learn it
• To calculate the number of rounds of division, divide the total time by the time for one round of division
• For the sample question, in three hours (180 minutes) the bacteria have undergone 9 rounds of division (180 / 20 = 9)
• Therefore, the number of bacteria after three hours is 2^9 = 512
• Standard form


  Expressing a number as a value between 1 and 10 multiplied by a power of 10
• In eight hours (480 minutes) the bacteria have undergone 24 rounds of division (480 / 20 = 24)
• The number of bacteria after eight hours is 2^24 = 16,777,216
• Expressed in standard form, this is 1.678 x 10^7