MICROBIOLOGY EXAM 3 REVIEW EXAM QUESTIONS WITH CORRECT VERIFIED ANSWERS | 100% PASS (A+ CERTIFIED)

MICROBIOLOGY EXAM 3 REVIEW EXAM QUESTIONS WITH CORRECT VERIFIED ANSWERS | 100% PASS (A+ CERTIFIED)What two categories can requirements for microbial growth to be divided into? Answer Physical Chemical Know all the classifications of microorganisms based on temperture requirements and the temp ranges for each group. Answer Psychrophiles -10 to 20 degrees C Mesophiles 25 to 40 degress C Thermophiles 50 to 100 degrees C Acidophiles (acid) Halophiles (Salt) Know Micro-organisms Ability to grow in acid or salt? Answer Acidophiles-tolerant to PH as low as 1.0 Halophiles PH most bacteria like 6.5-7.5 Know the effect of low and high osmotic pressure on a bacteria cell wall. Answer Low Osmotic pressure - expand High Osmotic Pressure - Shrink What is plasmolysis? Answer Shrinkage of the cells cytoplasm -------osmotic loss of H2O because of/greater # of solutes in surrounding medium. Know all terms for organsisms based o2 requirements Answer Obligate aerobes - growth only occurs where high o2 concentration Facultative anarobes - growth best where most o2 is present Obligate anarobes - growth only occurs where there is no o2 Aero tolerant anarobes - growth occurs evenly - o2 has no effect Microaerophiles-growth occurs only where low o2 concentration Know phases of growth for bacterial cells and what is going on for each phase Answer Lag phase: no growth but there is metabolic activity Log Phase: exponential growth occurs Stationary phase: period of equilibrium Death phase: population decreases at a logarhythmic rate