Microbiology 2024 Past Paper PDF

Chapter 3 & 4 Study Guide Microbiology 2024 1. In 1668, Francesco Redi performed an experiment to refute spontaneous generation. He left meat in containers that were open, covered with gauze, or tightly sealed. Which of the follow...

Chapter 3 & 4 Study Guide Microbiology 2024 1. In 1668, Francesco Redi performed an experiment to refute spontaneous generation. He left meat in containers that were open, covered with gauze, or tightly sealed. Which of the following observations is inconsistent with Redi's findings? a. Maggots formed on top of the gauze in the gauze-covered jars. b. Maggots did not form in the tightly sealed jars. c. Maggots formed in the uncovered jars d. Maggots formed in the gauze-covered jars. ANS: d 2. If "spontaneous generation" were true, which of the following would Pasteur have observed in his swan-neck experiment? a. The sterile broth would have been contaminated only when the swan-neck was broken. b. The sterile broth would have been contaminated only when the swan-neck was intact. c. The sterile broth would have been contaminated whether or not the swan-neck was intact or broken. d. The sterile broth would not have been contaminated whether or not the swan-neck was intact or broken. ANS: c 3. In 1745, John Needham published his experiment in support of "spontaneous generation". He briefly boiled broth infused with plant or animal matter, and sealed the flasks. After a few days, he observed that the broth had become cloudy. Which of the following could have explained Needham's experimental result knowing "spontaneous generation" is not true? Check all that apply. A. New microbes have arisen spontaneously from the boiled broth. B. Needham may not have sealed the flasks properly. C. Needham could have introduced microbes while sealing the flasks. D. Needham likely did not boil the broth enough to kill all the microbes. ANS: b,c,d 4. If "spontaneous generation" were true, which of the following would Redi have observed in his meat jar experiment? Check all that apply. a. Maggots would have formed in the tightly-sealed jars. b. Maggots would have formed in the open jars c. Maggots would not have formed in the open jars d. Maggots would not have formed in the tightly-sealed jars. ANS: a,b 5. Which of the following is correct about Pasteur's swan-neck flask experiment? Check all that apply. a. When the swan-neck is broken, air can enter the flask and reach the sterile broth. b. When the swan-neck is intact, air can travel freely through the neck and enter the flask. c. When the swan-neck is broken, airborne microbes can enter the flask and reach the sterile broth. d. When the swan-neck is intact, airborne microbes can travel freely through the neck and enter the flask. ANS: a,b,c 6. What was Louis Pasteur's contribution to the germ theory? a. He started using carbolic acid (phenol) spray disinfectant/antiseptic during surgery which became standard medical practice. b. He promoted handwashing, which reduced maternal mortality rate in hospitals. c. He proposed a series of postulates based on the idea that the cause of a specific disease could be attributed to a specific microbe. d. He suggested that if microbes were responsible for food spoilage and fermentation, they could also be responsible for causing infection. ANS: d 7. Which of the following are supporting evidence of the endosymbiotic theory? Check all that apply. a. Mitochondria and chloroplasts have their own DNA b. Mitochondria and chloroplasts have circular DNA genomes c. Mitochondria and chloroplasts have their own ribosomes d. Mitochondria and chloroplasts divide by binary fission ANS: a,b,c,d 8. Which of the following is not a part of the cell theory? a. All cells use DNA as genetic material b. Cells are the fundamental units of living organisms. c. All living things are composed of cells. d. All cells come from other cells. ANS: a 9. Before the germ theory was developed in the 1800s, what was the prevailing theory to explain what causes diseases? a. endosymbiotic theory b. theory of evolution c. cell theory d. miasma theory ANS: d 10. Why do scientists think that the evolution of mitochondria happened before the evolution of chloroplasts? a. Because all eukaryotic cells have mitochondria, and only some of them have chloroplasts. b. Because all eukaryotic cells have chloroplasts, and only some of them have mitochondria. c. Because mitochondria have their own DNA, and chloroplasts do not. d. Because chloroplasts have their own DNA, and mitochondria do not. ANS: a 11. Which of the following statements about endospores is correct? Check all that apply. a. They are produced by gram-positive bacteria. b. They contain normal water content and active metabolic activities. c. They contain high levels of calcium and dipicolinic acid. d. They are dormant structures capable of surviving unfavorable environmental conditions. ANS: a,c,d 12. Which of the following is not a passive transport mechanism? a. moving glucose down its concentration gradient b. osmosis c. pumping protons (H+) against its concentration gradient d. diffusion ANS: c 13. Which of the following statements about prokaryotic ribosomes is correct? Check all that apply. a. They are made of rRNA and carbohydrates b. They are made of rRNA and proteins. c. They are called 70S ribosomes. d. They are called 80S ribosomes. ANS: b,c 14. An antibiotic that targets bacterial ribosomes would stop bacteria from: a. synthesizing proteins b. maintaining cell integrity from the environment c. replicating their genetic material d. attaching to host cells ANS: a 15. You are a nurse working in a clinic. A patient with severe brain swelling comes in. What kind of IV solution would you use to help reduce brain swelling? a. Hypertonic b. Hypotonic c. Isotonic ANS: a 16. Which of the following components are present in all prokaryotic and eukaryotic cells? Check all that apply. a. Cell membrane b. Ribosomes c. Cell wall d. Mitochondria e. Cytoplasm ANS: a,b,e 17. Scientists have revived a 250-million-year-old bacterium buried underneath the Earth. The bacterium most likely produced: a. Endospores b. Fimbriae c. Ribosomes d. Flagella ANS: a 18. The cell envelope of gram-positive bacteria contains more lipids. a. True b. False ANS: b 19. Which of the following statements about bacterial glycocalyces is true? Check all that apply. a. Capsules are best visualized by negative stain. b. They contribute to biofilm formation. c. Slime layer contributes to greater pathogenicity than capsule. d. Bacteria with capsules are harder for immune cells to destroy ANS: a,b,d 20. Which of the following is found only in the cell walls of acid-fast bacteria? a. Mycolic acid b. Teichoic acid c. Lipopolysaccharide d. Peptidoglycan ANS: a 21. If a bacterial cell is put into a hypertonic solution, it will go through: a. Plasmolysis b. Crenation c. Lysis d. Flaccid ANS: a 22. Which of the following bacterial appendages is mostly used for motility? a. Flagella b. Pili c. Fimbriae d. Cilia ANS: a 23. Which of the following statements about mitochondria is false? a. They contain two layers of membranes. b. They contain their own DNA and ribosomes c. The outer membrane is extensively folded into cristae d. They contain enzymes for making ATP ANS: c 24. The nucleolus is the site for: a. rRNA synthesis and ribosome assembly b. mRNA synthesis c. chromosomal attachment to the nuclear envelope d. movement of materials into and out of the nucleus ANS: a 25. Which of the following is not a difference between bacterial and eukaryotic genomes? a. Bacterial DNA is not enclosed in the nucleus b. Eukaryotic DNA is wrapped around histone proteins c. Bacterial genomes contain circular DNA, whereas eukaryotic genomes contain linear DNA. d. They contain genetic materials. ANS: d 26. Which of the following cytoskeleton molecules are eukaryotic flagella made of? a. Microfilaments b. Myosins c. Intermediate filaments d. Microtubules ANS: d 27. Which of the following processes rely on endocytosis? Check all that apply. a. SARS-CoV-2 infects a host cell. b. Fungal cells obtain nutrients from decaying matters. c. Macrophages destroy invading bacteria. d. Neurotransmitters released by neurons. ANS: a,b,c 28. Which of the following statements about eukaryotic ribosomes is correct? Check all that apply. a. Free ribosomes in the cytoplasm are used to synthesize soluble proteins. b. They are called 70S ribosomes c. Free and RER ribosomes are made of different components d. Ribosomes on RERs are used to synthesize membrane-bound or secreted proteins. ANS: a,d 29. Which of the following is actin filaments not involved in? a. Muscle contraction b. Pseudopodia c. Cilia d. Contractile ring formation during cell division ANS: c 30. Which of the following eukaryotic organisms do not have a cell wall? a. A giant kelp b. A squirrel c. A mushroom d. An oak tree ANS: b 31. Which of the following organelles is critical to the function of immune cells? a. Lysosome b. Golgi apparatus c. Peroxisome d. Endoplasmic reticulum ANS: a 32. When a protein destined to be secreted is made in a cell, which of the following represents the correct order of organelles that it travels through? a. Golgi, ER, transport vesicles, secretory vesicles b. Golgi, transport vesicles, ER, secretory vesicles c. ER, secretory vesicles, Golgi, transport vesicles d. ER, Golgi, transport vesicles, secretory vesicles e. ER, transport vesicles, Golgi, secretory vesicles ANS: e 33. E. coli making vitamin K in the human intestine represents which kind of relationship? a. Commensalism b. Ammensalism c. Parasitism d. Mutualism ANS: d 34. Staphylococcus epidermidis producing chemicals to kill other skin bacteria represents which kind of relationship? a. Mutualism b. Commensalism c. Ammensalism d. Parasitism ANS: c 35. What is/are the goal(s) of the Human Microbiome Project? Check all that apply. a. to characterize the microbes in soil samples] b. to characterize the microbes in hospitals c. to create a large repository of the gene sequences of important microbes found in humans d. to characterize the human microbiota in patients with different diseases ANS: c,d 36. Mycobacterium tuberculosis causing TB in humans represents which kind of relationship? a. Mutualism b. Parasitism c. Commensalism d. Ammensalism ANS: b 37. What percent of prokaryotes are considered to be human pathogens? a. < 1% b. 10% c. 5% d. 50% ANS: a 38. In what way do plants and animals rely on prokaryotes? Check all that apply. a. Clean up environmental contamination b. Scientists are exploring the ability of some bacteria to break down plastics. c. Nitrogen-fixing bacteria make ammonia available for plants, and in turn animals. d. Decomposing bacteria return nutrients back to the soil. ANS: a,b,c,d 39. Which of the following has been used to classify bacteria? Check all that apply. a. Genetic evidence b. Physiological properties c. Staining patterns d. Biochemical properties ANS: a,b,c,d 40. Staphylococcus epidermidis using dead skin cells as nutrient source represents which kind of relationship? a. Ammensalism b. Commensalism c. Mutualism d. Parasitism ANS: b 41. Bacteria in class epsilonproteobasteria are microaerophilic. This means they: a. require a small amount of oxygen b. require atmospheric level of oxygen c. require no oxygen ANS: a 42. Which of the following describes a coliform? a. A gram-negative bacterium that does not ferment lactose. b. A gram-positive bacterium that ferments lactose. c. A gram-negative bacterium that ferments lactose. d. A gram-positive bacterium that does not ferment lactose. ANS: c 43. Which of the following statements about Helicobacter pylori is false? a. It is a pathogen that does not provide any benefit to the host. b. It is part of the normal microbiota in some people's stomach. c. It is a common cause of gastric ulcer. d. It produces urease to counter the acid environment of the stomach. ANS: a 44. Which of the following describes oligotrophs? Check all that apply. a. Organisms living in low-nutrient environments. b. Disease-causing organisms c. Glacial ice microbes d. Organisms that require a large amount of nutrients. ANS: a,c 45. Which of the following statements about Neisseria is false? a. They can cause gonorrhea and meningitis b. They are difficult to culture and grow best on chocolate agar c. They are strictly aerobic d. They are gram-negative diplococci ANS: c 46. Which of the following human pathogens does not belong to class gammaproteobacteria? a. Neisseria meningitidis b. Pseudomonas aeruginosa c. Salmonella enterica d. Vibrio cholerae ANS: a 47. The word "fastidious" describes microbes that are: a. difficult to culture due to specific nutrient demands b. difficult to culture due to general nutrient demands. c. easy to culture due to general nutrient demands d. easy to culture due to specific nutrient demands ANS: a 48. Which of the following bacteria is a major contributor to respiratory infections in cystic fibrosis patients? a. Klebsiella pneumoniae b. Legionella pneumophila c. Pseudomonas aeruginosa d. Haemophilus influenzae ANS: c 49. Which of the following is/are true about Bacteroides? Check all that apply. a. one gram of human feces contains up to 100 billion Bacteroides cells b. they are obligate anaerobes c. they make up about 30% of our gut microbiota d. most of them are mutualistic partners to us e. they help us break down complex carbohydrates ANS: a,b,c,d,e 50. What do all photosynthetic bacteria have in common? Check all that apply. a. They all use sunlight as their primary source of energy. b. They all belong to the phylum cyanobacteria. c. They all contain bacteriochlorophylls d. They all produce oxygen. ANS: a,c 51. Which of the following is/are true about spirochetes? Check all that apply. a. they contain axial filaments (internal flagella) b. darkfield microscopy is helpful to view them c. they are difficult to examine by Gram stain d. they have long, spiral-shaped bodies e. they are highly motile ANS: a,c,b,d,e 52. Spirochetes cause the following diseases except for: a. Chlamydia b. Syphilis c. Lyme disease d. Leptospirosis ANS: a 53. How do the spirochete flagella differ from other bacterial flagella? Check all that apply. a. Spirochetes have more flagella than other bacteria. b. Spirochete flagella are internal flagella. c. Spirochete flagella are embedded in the periplasmic space d. Spirochete flagella have different functions than other flagella ANS: b,c 54. Which of the following does not belong to the CFB group? a. Bacteroides b. Fusobacterium c. Chlamydia d. Cytophaga ANS: c 55. Which of the following genus of high G+C gram-positive bacteria contains pathogens that cause TB or Hansen's disease (leprosy)? a. Garderella b. Corynebacterium c. Myobacterium d. Nocardia ANS: c 56. Why are infections caused by Staphylococcus aureus a concern for healthcare professionals? Check all that apply. a. S. aureus is the most common cause of bacterial pharyngitis. b. MRSA and VRSA are highly contagious, making them serious threats in hospitals, nursing homes and dialysis clinics c. S. aureus is an important infectious agent associated with IV catheters. d. Many strains of S. aureus exhibit resistance to multiple antibiotics. ANSL b,d 57. Which of the following genus of low G+C gram-positive bacteria contains the pathogen that produces the most lethal biological toxin? a. Staphylococcus b. Streptococcus c. Bacillus d. Clostridium e. Lactobacillus ANS: d 58. Which of the following high G+C gram-positive bacteria are part of microbiota in the GI tract, vagina and mouth, and are used in probiotic and yogurt production? a. Propionibacterium b. Micrococcus c. Bifidobacterium d. Corynebacterium ANS: c 59. Based on genetic evidence, gram-positive bacteria are divided into which two groups? a. high G+A and low G+A b. high G+C and low G+C c. high C+T and low C+T d. high C+A and low C+A ANS: b 60. Which of the following low G+C gram-positive bacteria produce endospores? Check all that apply. a. Staphylococcus b. Enterococcus c. Lactobacillus d. Clostridium e. Bacillus ANS: d,e 61. Deinococcus radiodurans is considered a polyextremophile. What extreme conditions can it survive? Check all that apply. a. Extreme acidity b. Drought c. Vacuum d. Radiation e. Extreme heat ANS: a,b,c,d,e 62. Which of the following descriptions of deeply branching bacteria is accurate? Check all that apply. a. Many of them are thermophiles and hyperthermophiles b. Many show resistances to UV light and ionizing radiation c. It is common to find these bacteria in polar icecaps d. It is common to find these bacteria in deep ocean hydrothermal vents. ANS: a,b,d 63. Scientists think that the deeply branching bacteria may provide clues to ancient life forms because they live in extreme environments that resemble the conditions of early Earth. a. True b. False ANS: a 64. Which of the following describes the condition of early Earth? Check all that apply. a. No oxygen b. Low levels of radiation c. Cold d. High levels of radiation e. Hot ANS: a, d,e 65. Hyperthermophiles contain which chemical components in their cell wall as an adaptation? a. Peptidoglycan b. Mycolic acid c. Teichoic acid d. Diaminopimelic acid ANS: d 66. How did the group get its name "deeply branching bacteria"? a. Because they have more branches than other groups of bacteria. b. Because they are closer to the 'last universal common ancestor' than other groups on the phylogenetic tree of life. c. Because they have fewer branches than other groups of bacteria. d. Because they are more distant to the ‘last universal common ancestor’ than other groups on the phylogenetic tree of life. ANS: b 67. In general, the genomes of archaea are _____ and ______ than those of bacteria. a. larger; more complex’ b. smaller; more complex c. larger; less complex d. smaller; less complex ANS: a 68. Archaea have not been associated with human diseases because many of them are: Check all that apply. a. Thermophiles b. Extremophiles c. Hyperthermophiles d. Halophiles ANS: a,b,c,d 69. One of the adaptations that allows archaea to live in extreme conditions is their cell membrane, which contains _____ linkage with ____ chains, instead of _____ linkage with ______ chains in bacterial cell membrane. a. ester; unbranched; ether; branched b. ester; branched; ether; unbranched c. ether; unbranched; ester; branched d. ether; branched; ester; unbranched ANS: d 70. Methanogens are: Check all that apply. a. Organisms that can reduce CO2 in the presence of hydrogen and produce methane. b. Organisms that live in very hot or very cold places. c. Organisms that can metabolize methane d. Organisms that live only in very hot places. ANS: a,b 71. Halobacteria may live in: Check all that apply. a. Human gut b. Some salty lakes in antartica c. Environments with salt concentration close to 36% d. Freshwater lakes e. Dead sea ANS: b,c,e