Solved Questions on Cell Internal Structure in Biology - Quiz 2 | MMG 301, Quizzes of Microbiology

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MMG Unit 2 Quiz Questions Lecture 11: Cell Envelope

1. The hydrophilic region of bacterial membrane phospholipids is located on the of the lipid bilayer. The hydrophobic tail of the phospholipids is located the lipid bilayer.

2. What is the charge of the polar head of phospholipids? A) Always negative because of the phosphate group B) It varies, because the polar group attached to the phosphate group varies from one phospholipid to another C) Always positive because of the positive charge of ethanolamine D) Neutral because the negative charge (phosphate) and positive charge (ethanolamine) neutralisze each other E) Phospholipids do not have polar heads

3. Which proteins in the outer membrane of Gram negative bacteria are channels for the non-specific transport of small molecules? A) Enzymes B) Braun's lipoprotein C) Porins D) All proteins transporting small molecules through the outer membrane are specific to given small molecules E) Receptors

4. Which molecule anchors the outer membrane to the peptidoglycan in Gram negative bacteria? A) Porins B) Braun's lipoprotein C) Murein molecules D) Lipoteichoic acids E) Lipopolysaccharides

5. Which part of the lipopolysaccharide (LPS) helps Gram negative bacteria escape the immune system of warm- blooded animals A) Lipid A B) The O-specific polysaccharide C) The core polysaccharide Lecture 12: Cell Envelope

6. T/F: A symporter takes up two external solutes simultaneously while antiporters export two internal solutes simultaneously. FALSE outside inside

2. Which of the following statements is False? a. S-layer is highly ordered b. S-layer covers the cell surface c. Bacteria often lose their S-layer when grow in a laboratory d. Under physiologic conditions the S-layer is fluid
3. T/F: Antibiotics that target peptidoglycan formations are effective against Achaea. False
4. What does DAP stand for? Diaminopimelic Acid
5. A gentle lysozyme digestion in a protective isotonic solution releases protoplast from Gram positive, or spheroplast from Gram negative bacteria. Lecture 13: External Components
   1. T/F: Gas vesicles are considered a viable strategy for bacteria to move. True
   2. Bacteria need to be mobile b/c: a. Escape Waste b) Escape predators, host defenses c) Of the need to find nutrients d) All of the Above
   3. Match a. Fimbriae: Numerous and small, used in adhesion b. Pili: Some are used in bacterial conjugation c. Flagella: Allow the bacterium to move (mobility)
   4. Which part of the flagellum controls rotation and direction of rotation? a. Hook d) L and P Rings b. Mot Proteins e) Fli proteins c. MS and C rings
   5. Peritrichous flagella rotation counterclockwise bacteria to move forward. Peritrichous flagella rotate clockwise cause bacteria to tumble
   6. What is the direct source of energy used for flagellum rotation? a. NADH d) H+ motive force b. Direct consumption of maltose e) Na+ motive force c. ATP
   7. T/F: Chemotaxis can result in bacterial cells swimming down a concentration gradient rather than up a concentration gradient….True Lecture 14: Cell Internal Structures
   8. When the 50-S and 30-S subunits of bacterial ribosomes combine, they form an 80-s Ribosome. FALSE
   9. Which of the statements about sulfur granules is False? a. Sulfur granules are accumulated by bacteria that use H2S as electron donor b. Sulfur is water soluble c. Sulfur granules can provide bacteria with energy d. Sulfur granules are easily seen by phase contrast microscopes
   10. T/F: In a hammer experiment, after the cork is hit with a hammer, the bacteria that sink have collapsed gas vesicles. These bacteria must make new gas vesicles in order to float again. True
   11. Which of the following statements about Anammoxosomes is True? a. Anammoxosomes are surrounded by a lipid bilayer b. The Anammox process consists of four successive redox reactions that create H+ motive forces c. The Anammox process consists of four successive redox reactions that reduce NO2- to N d. All of the Above are True
   12. T/F: When a bacterial cell is starved for carbon, it might degrade glycogen for carbon and energy Anammoxosomes True
   13. What is the purpose of Carboxysomes? a. Fix Glucose d) Store water for the cell b. Concentrate CO2 for RubisCO activity e) Protect cells from CO2 toxic effect c. Make proteins

Lecture 15: Microbial Nutrition, Cultivation, and Enrichment

1. T/F: Primary means to sterilize media and lab equipment such as micropipette tips and microcentrifuge tubes is to autoclave TRUE
2. T/F: Aseptic technique is ok to disregard in lab as long as you always use septic technique FALSE
3. Four most abundant elements that make up dry cell weight are easily remembered using HONC a. HONC stands for: Hydrogen Oxygen Nitrogen Carbon
4. If you want to isolate colonies you should make a: a. Streak plate c) Spread plate b. Pour plate d) All of the Above
5. Fastidious organisms are: a. Organisms that grow with CO2 as only Carbon source b. Organisms that are not able to synthesize certain of its growth factors c. Organisms that only need the 9 macronutrients for growth
6. T/F: Limiting nutrients are nutrients that inhibit cell growth FALSE
7. Match the Following: a. Complex Medium: Undefined chemical composition b. Rich Medium: Contains all chemical required for growth plus others c. Minimal Medium: Contains only those chemicals required for growth d. Synthetic Medium: All components are exactly known e. Enriched Medium: Complex medium that contains extra components f. Lecture 16: Bacterial Division and Differentiation
8. What is the evolutionary advantage of an organism that can make spores? A) All these statements are correct. B) Some spores can survive autoclaving C) Spores are the most resistant form of life on Earth D) It is a great survival/dispersal strategy
9. What does "CFU" stand for? Colony Forming Unit
10. Is the optical density (measured on a spectrophotometer) of a suspension containing a high concentration of bacterial cells an accurate estimate of the number of cells present in the suspension? NO
11. Generation time varies greatly from one to another. It also depends on the growth
12. Why are rod-shaped bacteria rod-shaped? A) MinCD oscillate from cell pole to cell pole B) Min E oscillations from cell pole to cell pole allow the FtsZ ring to form at equal distances two cell poles C) MreB distributes cell wall synthesis all along the cell D) The FtsZ ring attracts the divisome proteins to the center of the cell E) FtsZ locates the division septum in the middle of the cell
13. Spores are resistant to heat and chemicals, except antibiotics. B) False species conditions

Lecture 17: Population growth in batch and continuous cultures

1. A chemostat is used to: A) Maintain a microorganism in constant exponential growth B) Concentrate the CFUs/mL C) Produce large amounts of chemicals excreted by bacteria during stationary phase D) Washout the culture E) Aerate a culture better than a test tube
2. Why does the concentration of the limiting nutrient in the chemostat start increasing at dilution rates above the steady state region? A) The nutrient concentration is also increased in the fresh medium fed in the chemostat NO B) The bacterial cells no longer need this nutrient for growth NO C) Another nutrient has become limiting NO D) Bacteria have reached their maximum growth rate and can no longer assimilate all the limiting nutrient provided at high dilution rates E) The bacterial cells are dying at higher dilution rates NO
3. The best phase to study the physiology of a microorganism is during the death phase because the population is very uniform. FALSE
4. Match the following phases of growth with an explanation of what is happening in a culture. Stationary: Cells are coping with rarefied nutrients and accumulated waste Death: There is too much waste in the culture and cells are dying Exponential: Cells are growing at a constant rate Lag: Cells are adjusting to new medium

5. T/F: Many human pathogens exist as VBNC TRUE Lecture 18: Physiology of population-Regulated growth

1. Which of the following strategies are employed by bacteria that are trying to survive in stationary phase? a. Increase cell size d. 2 of 3 are valid strategies b. Increase in flagella and Fimbriae e. All 3 are valid strategies c. More broad range substrate transport systems
2. T/F: In unamended soil, bacteria division is frequent even though nutrients are not abundant FALSE
3. Negative stringent control causes a down-regulations of the synthesis of macromolecules that are required for fast growth. Positive stringent control causes an increase in the synthesis of protein that allow stationary phase survival
4. T/F: Bacteria can respond to quorum sensing molecules of other bacterial species TRUE
5. What triggers a bacterial response in quorum sensing? a. Autoinducer concentration increasing to a specific threshold value b. Bacterial envelope blocking transport of Autoinducer c. Disappearance of Autoinducer from the environment d. Bacteria start to produce the Autoinducers e. Bacteria touch each other

6. Biofilms make their own microenvironments that a. Protect from/lessen the effect of anti-microbials b. Are a source for microbial inoculums that disperse to new habitats c. Sequester nutrients d. Enhance bacterial ability to exchange DNA e. ALL OF THE ABOVE ARE CORRECT Lecture 19:
7. To be good osmolytes to help cells in hyperosmotic conditions, small molecules should have which properties? a. Be able to diffuse freely in and out of the cell b. Not be able to diffuse freely in and out of the cell c. Non-toxic to the cell d. Be highly solube e. B, C, and D are Correct
8. T/F: Validation of proper autoclave function can be done with the use of Pre-packaged bacterial endospores and/or autoclave tape True
9. The fact that bacteria that grow at very acidic or very basic pH values keep their cytoplasm at a near pH near neutral is called pH homeostasis
10. Define Plasmolysis a. Loss of water and collapse of internal structures
11. T/F: Pateurization is the complete sterilization of a liquid FALSE
12. Most microbes that humans encounter are mostly: a. Hyperthermophiles c. Psychrophiles b. Mesophiles d. Thermophiles
13. Enzymes and Proteins require optimal ______ to function a. Proteins can function under all conditions. They do not require optimal environments to function b. pH only c. Temperature only d. Temperature and pH
14. Why is superoxide reductase more common than superoxide dismutase in anaerobes? a. Superoxide reductase does not produce Oxygen b. It is expressed the same operon as peroxidase, which is expressed only in anaerobes c. Superoxide reductase’s reaction consumes a single superoxide at a time d. Superoxide reductase produces Oxygen Lecture 20
15. Overuse of antibiotics creates a selective pressure in favor of antibiotic resistant microbes
16. Which antibiotics are broad spectrums? a. Vanocomycin and Penicillin d Penicillin b. Vanocomycin e. Tetravycline and Penicillin c. Tetracycline
17. T/F: Higher the therapeutic index, the better the chemotherapeutic agent TRUE
18. Which of the following statements are true about B-lactams? a. They are produced by fungi b. They inhibit transpeptidase meaning that they ultimately inhibit peptidoglycan synthesis c. B-lactams work against both Gram Negative and Gram Positive bacteria d. Penicillin G was the first B-lactam discovered and produced commercially e. Three of the Four statements are correct
19. T/F: Vancomycin is not a B-lactam, but it still prevents cell wall synthesis TRUE
20. Aminoglycoside antibiotics are only used as reserve antibiotics when others fail b/c of serious side- effects and bacterial resistance