BIO 250 Straighterling Final Exam (Microbiology) 60 Questions With Correct Answers Latest Update 2023 Graded A+

1-What microbial process was responsible for changing Earth’s atmosphere from one without oxygen to one with oxygen? Select one: a. anaerobic respiration b. decomposition c. oxygenic photosynthesis d. temperature regulation 2-In the nitrogen cycle, which of the following phases involves the release of nitrogen as into the Earth’s atmosphere? Select one: a. ammonification b. denitrification c. nitrification d. nitrogen fixation 3-Farmers commonly inoculate legume crops with Rhizobium bacteria for which of the following purposes? Select one: a. The bacteria cause the crops to use less water and, therefore, be more drought-resistant. b. The bacteria kill off other, more virulent, bacteria that are harmful to the crops c. The bacteria secrete a chemical that inhibits the growth of unwanted weeds. d. The two form a symbiotic relationship increasing the plant’s access to nitrogen. 4-In the secondary phase of wastewater treatment, why is air injected into the sludge as it is stirred and recirculated? Select one: a. The bioremediators need oxygen. b. The air lowers the pH of the solution. c. The air keeps the sludge from clogging the pipes. d. Oxygen kills the bacteria in the water. 5-Which of the following microorganisms is used to make yogurt? Select one: a. Lactobacillus bulgaricus b. Pennicillium roqueforti c. Streptococcus lactis d. Yeast