Final answer:
Starting with 500 bacteria and undergoing binary fission every 20 minutes for an hour would result in a total of 4000 bacteria due to exponential growth.
Step-by-step explanation:
To calculate how many bacteria would be present after 500 bacteria undergo fission every 20 minutes for an hour, we need to understand the concept of exponential growth. Binary fission is a form of asexual reproduction in which a parent bacterium divides into two identical daughter cells. If a population doubles every cycle of fission, and one cycle takes 20 minutes, then in one hour, which consists of three 20-minute cycles, the number of bacteria will double three times.
Starting with 500 bacteria, after the first 20 minutes, there would be 500 x 2 = 1000 bacteria. After the second 20-minute cycle, the population would double again to 1000 x 2 = 2000 bacteria. Following the third cycle, there would be 2000 x 2 = 4000 bacteria. Thus, after one hour of growth under these conditions, there would be a total of 4000 bacteria.