1. why don’t microorganisms in cultures exhibit constant exponential growth? what are some steps you could take to extend the lifespan of a microbial culture? 2. using a textbook or a reputable online source, describe how lab cultures are maintained in a continual pattern of growth. focus particularly on those used in biotechnology, such as e. coli, which is used to make human insulin. 3. which of these has a constant growth pattern: an open system or a closed system? 4. a human patient represents what kind of system for bacterial infections? 5. you’re a physician trying to isolate bacterial colonies from the human gut in attempt to diagnose a gastrointestinal infection. you streak your sample on a growth media containing glucose, amino acids, and salts that contain both sulfur and phosphorous with a ph of 7. you incubate the plates in aerobic conditions at 37 ˚c for three days, at which point you can see clear bacterial colonies forming on the plate. would you feel confident in stating that you had successfully cultured all the bacteria from your gut sample? why or why not?