What is the doubling time for bacteria after the initial two hours in optimal conditions?

The doubling time for bacteria refers to the period it takes for a population of bacteria to double in number under optimal conditions. In many situations, optimal conditions for growth include the right temperature, pH, and nutrients, which can significantly affect bacterial reproduction rates.

In this context, the best answer indicates a doubling time of every 20 minutes. This duration is consistent with the rapid growth rates observed in various types of bacteria, particularly in the logarithmic phase of their growth cycle. Given these ideal conditions, bacteria can reproduce through binary fission, where each bacterium divides into two new cells, effectively doubling the population.

The 20-minute doubling time means that after an initial period of two hours (which equals 120 minutes), the bacteria would have doubled several times. Specifically, in two hours, there would be six 20-minute intervals (120 divided by 20), allowing the bacteria to grow exponentially. This illustrates how quickly bacteria can multiply, ultimately leading to an explosive growth if conditions remain favorable.

The other options suggest longer intervals for the bacterial doubling time, which would not align with typical expectations when conditions are optimal. Therefore, the 20-minute interval represents a realistic and biologically relevant rate for bacterial population growth in such favorable circumstances.