Straighterline Microbiology Final Exam Practice BIO250_Saylor_V5 Practice Questions 1. In the nitrogen cycle, which of the following steps involves removal of nitrogen from the atmosphere by bacteria? a. Ammonification b. Denitrification c. Nitrification d. Nitrogen fixation Answer is d. In nitrogen fixation, nitrogen is removed from the atmosphere by nitrogen-fixing bacteria and converted to ammonia 2. If enough H+ ions are added to pure water to raise the H+ concentration of the solution to ten times higher than the original concentration, what is the resulting OH- concentration of the solution? a. 10-5 M b. 10-6 M c. 10-7 M d. 10-8 M Answer is d. The H+ concentration would be 10-6 M, resulting in the OH- being 10-8 M 3. Fungi are able to reproduce asexually by creating conidiospores and sponrangiospores. Which of the following is an accurate explanation for why it is advantageous that they are also capable of sexual reproduction? a. Asexually produced offspring are more likely to compete for resources and will kill off the parental fungi b. Fungi normally produce sexually but produce asexually in harsh conditions such as severe drought c. Offspring from two parents may have variations in form and function that contribute to survival of the species. d. Sexual reproduction produces more offspring at a faster rate than spore formation Answer is c. Sexually produced offspring have traits from both parents and may develop variations that give them an advantage for survival. 4. In a laboratory bacterial cell culture that had been infected by a virus, plaques are areas in which a. Bacterial cells are resistant to the virus and have not been infected b. There is no nutrient available for the bacteria to grow c. The virus has spread and left behind the remains of dead cells d. The virus has not yet spread to the area of cells Answer is c. Plaques are areas in which the bacteria have been destroyed by the virus and all that remain are dead cells 5. The sun’s energy is delivered as discrete packets that travel as waves and are called a. ATP b. Carotenoids c. NADP d. Photons Answer is d. 6. Which of the following is a characteristic of aerobic respiration? This study source was downloaded by 100000888008615 from CourseHero.com on 07-18-2024 04:02:14 GMT -05:00 https://www.coursehero.com/file/155492301/Straighterline-Microbiology-Final-Exam-Practicedocx/ a. Oxygen-containing ions act as the final electron acceptors in electron transport b. The process includes glycolysis, the Krebs cycle, and the electron transport chain c. Aerobic respiration produces a total of 2 ATP molecules d. Aerobic respiration produces lactic acid Answer is c. aerobic respiration produces a total of 36 – 38 ATPs. Anaerobic respiration only produces 2 ATP. 7. In completing the protein synthesis in a prokaryote, what basic message is carried by a specialized codon that has no corresponding tRNA? a. Fold peptide chain b. Terminate here c. Add cofactor d. Clip starting amino acid Answer id b. The specialized codon signals the end of protein synthesis, there is not RNA because it is only needed if the process is to continue 8. Microbial drug resistance can be caused by mutations or by introduction of new genes into a population. Which of the following can only be caused by the introduction of new genes into a population? a. A metabolic pathway in the bacterium is shut down b. Binding sites for the drug are reduced in number or affinity to the drug c. New enzymes that inactivate the drug are synthesized d. Uptake of the drug into the bacterium is diminished Answer is c. This can only occur if new genes into a population. 9. Why do the hands, feet and breasts have more lymphatic vessel for host defense than other areas of the human body? a. They have a high risk of infection due to frequent contact b. They have a greater density c. They require complex movements of fluids from the extremities d. They are located a long distance from the thalamus Answer is a. The hands, feet and breasts are the most likely sites on the body for contact with infectious agents 10. Penicillin functions as an antimicrobial agent by inhibiting bacterial a. Cell wall synthesis b. Folic acid synthesis c. Protein synthesis d. RNA and DNA function Answer is a. Penicillin belongs to a class of antibacterial agents that interfere with the production of the material that makes up the bacterial cell wall. The bacteria must constantly replace this material, or they will become susceptible to rupture due to osmotic pressure