Straighterline Micro 250 Final Exam Prep | Complete Solutions (Answered)

Straighterline Micro 250 Final Exam Prep | Complete Solutions (Answered) Which class of eukaryotic microorganisms can be subdivided into groups such as Mastigophora, Sarcodina, Ciliophora, and Apicomplexa? A. Helminths B. Algae C. Protozoa D. Fungi Genetic material can be excised from one chromosome and directly integrated into another via A. conjugation. B. transformation. C. transduction. D. transposons. Which immune cell secretes numerous cytokines that help to coordinate the response of other immune cells? A. B cell B. TH cell C. TC cell D. Platelets Which of the following enzymes are used to amplify DNA during PCR? A. restriction endonuclease B. DNA polymerase C. reverse transcriptase D. DNA ligase In the nitrogen cycle, which of the following steps involves removal of nitrogen from the atmosphere by bacteria? nitrogen fixation, In nitrogen fixation, nitrogen is removed from the atmosphere by nitrogen-fixing bacteria and converted to ammonia. 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? 10 -8M Fungi are able to reproduce asexually by creating conidiospores and sporangiospores. 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. In a laboratory bacterial cell culture that has 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 that area of cells. The sun's energy is delivered as discrete packets that travel as waves and are called a. ATP. b. carotenoids. c. NADP. d. photons. Which of the following is a characteristic of aerobic respiration? 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. n completing 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." The specialized codon signals the end of protein synthesis; there is not RNA because it is only needed if the process is to continue. 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 This can only occur if new genes are introduced into the population. Why do the hands, feet, and breasts have more lymphatic vessels for host defense than other areas of the human body? a. They have a high risk for infection due to frequent contact. b. They have a greater density of nerves. c. They require complex movement of fluids from the extremities. d. They are located a long distance from the thalamus. 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. 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. If enough ions are added to pure water to raise the concentration of the solution to ten times higher than the original concentration, what is the resulting concentration of the solution? - The study of evolutionary relationships among organisms is called Phylogeny The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from Last Universal Common Ancestor Organisms called parasites are always harmful to their host. Which of the following does not indicate microbe involvement in energy and nutrient flow Thermal hot springs warmed by heat from earth's interior The subatomic particles that surround the nucleus are the Electrons The number one worldwide infectious diseases are respiratory diseases A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other carbons and 2 hydrogens. saturated One technique for staining bacteria for viewing under the microscope is called the Gram stain. In this technique, alcohol is used as a decolorizer because it degrades the outer membrane found in some bacteria. What chemical component of the cell does alcohol affect? lipid If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X? 95X NASA has published a list of criteria for identifying fossil bacteria in samples from Mars, as part of a search for evidence of life. Which of the following is good evidence for the presence of bacterial cells? cell size of 0.5 to 2 microns Which type of microscope achieves the greatest resolution and highest magnification? electron Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled? a solid medium a spongiform encephalopathy of humans Creutzfeldt-Jacob disease The term that refers to flagella at both poles of the cell is ______. Amphitrichous In the condition called athlete's foot, the fungus Trichophyton consumes the keratin protein found in hair, nails, and dead skin. Which of the following descriptors does not apply to Trichophyton? Saprobe During the Gram stain, the application of alcohol results in the decolorization of ______ cells. gram-negative The size of a eukaryotic ribosome is _ 80s Sterilizing filters have a pore size of 0.22 μm. Which of the following statements is true? Bacterial cells are typically between 1-10 μm and are blocked by the filter, whereas most viruses are between 20 and 200 nm and therefore pass through. One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a/an _____ capsid. Icosahedral The purpose of staining cells on a microscope slide is to ______. a. kill them b. secure them to the slide c. enlarge the cells d. add contrast to see them better e. observe motility Many chronic infections are caused by microbes that associate in communities termed ______. a. biofilms b. virions c. sediments d. microbiota One nucleotide contains one a. phosphate. b. pentose sugar. c. nitrogen base. d. All of the choices are correct. Characteristics shared by all cells include a. a membrane serving as a cell boundary. b. the possession of genetic information. c. the presence of cellular fluid. d. All of the choices are correct. The important solvent associated with living things is ______. a. carbon dioxide b. sodium chloride c. ethyl alcohol d. benzene e. water A reducing medium contains a. sugars that can be fermented. b. extra oxygen. c. hemoglobin, vitamins, or other growth factors. d. substances that remove oxygen. e. inhibiting agents. Astrobiology is considered a sub-discipline of microbiology because a. life elsewhere in the universe is likely to be microbial. b. microbes are known to exist on other planets. c. all extraterrestrials known are microbial. d. only microbes can reproduce under the extreme conditions in outer space. Using microbes to detoxify a site contaminated with heavy metals is an example of ______. a. biotechnology b. bioremediation c. decomposition d. immunology e. epidemiology Trees of life that illustrate the phylogenetic relationships of all organisms were traditionally based on ______; newer methods for determining phylogeny rely on ______. a. morphology; nucleic acid sequences b. nucleic acid sequences; morphology c. morphology; virology d. morphology; nutritional requirements e. nucleic acid sequences; microbiomes Which term refers to the microscope's ability to show two separate objects as discrete and distinct? a. Resolution b. Magnification c. Refraction d. Contrast Hydrogen bonds a. result from attractive forces between molecules with polar covalent bonds. b. result from attractive forces between molecules with polar ionic bonds. c. result from attractive forces between molecules with nonpolar covalent bonds. d. result from attractive forces between molecules with nonpolar ionic bonds. e. are the strongest bonds between molecules. Which type of medium would be the best choice when shipping a sample of bacteria from a clinic to a laboratory for testing? a. Transport medium b. Eosin-methylene blue agar c. Blood agar d. Thioglycolate medium A microbiologist must culture a patient's feces for intestinal pathogens. Which of the following components would likely be present in a selective medium for this purpose? a. NaCl b. Sheep red blood cells c. Bile salts d. Thioglycolic acid e. Peptone Which of the following historical microbiologists is incorrectly paired with his contribution to the science? a. Francesco Redi: tested spontaneous generation with meat exposed to the air or covered with cloth b. Antonie van Leeuwenhoek: made and used quality magnifying lenses to observe and record microorganisms c. Louis Pasteur: demonstrated that anthrax was caused by a bacterium d. Joseph Lister: promoted disinfecting hands and air prior to surgery Which of the following is a scientific name? a. Gram-positive streptococcus b. Streptococcus pyogenes c. Anthrax d. Streptobacilli Ionic bonds a. result from sharing electrons. b. result from transferring electrons. c. result from like charge attraction. d. are the weakest chemical bonds. e. always involve carbon. Which of the following is a correct description of a component of the ATP molecule? a. Sugar: deoxyribose b. Nitrogenous base: alanine c. High energy bond: peptide bond d. Sugar: ribose e. High energy bond: glycosidic bond A scientist studying the sequence of nucleotides in the rRNA of a bacterial species is working on a. determining evolutionary relatedness. b. bioremediation. c. recombinant DNA. d. nomenclature. e. determining if that species is the cause of a new disease All of the following are polysaccharides except a. dextran in some bacterial slime layers. b. agar used to make solid culture media. c. a cell's glycocalyx. d. cellulose in certain cell walls. e. sterols in cell membranes Thioglycolate medium contains the following: yeast extract, pancreatic digest of casein, glucose, L-cysteine, sodium chloride, sodium thioglycolate, and agar. It is considered a complex medium because a. both yeast extract and pancreatic digest of casein are not chemically defined. b. it has multiple ingredients for a broad range of nutrients. c. depending on their oxygen utilization pattern, organisms will grow differently on it. d. thioglycolate has a carbon-sulfur bond that many microbes cannot break enzymatically Table 3.6 in your textbook uses Paramecium to illustrate several types of light microscopy. Each image is magnified 230X and measures about 4 cm. The actual size of a Paramecium is about ______. a. 175 μm b. 0.2 μm c. 4,000 μm d. 920 μm e. 57.5 μm In the experiments constructed by Pasteur to disprove spontaneous generation, swan-necked flasks were used. Why was this shape of flask used in this experiment? a. The glass necks needed to be open to the air, yet constructed so that bacteria would settle in the lowest part of the neck. b. These flask shapes were the easiest and cheapest to produce. c. The shape of the glass neck allowed the bacteria into the flask and then into the media, but air could not enter. d. Because the glass necks were stretched out, the heat used to sterilize the medium inside of the flask could not kill the bacteria in the neck. A pure culture contains a. only one identified species of microorganism. b. only bacteria. c. microbes from a single source. d. a variety of species from the same genus. Which of the following parts of a microscope magnifies the specimen to produce a real image of the specimen? a. Condenser b. Objective lens c. Ocular lens d. Body e. Nosepiece In the cell cytoplasm, molecules of ATP are a ______. a. solute b. solvent All cells contain a. ribosomes for protein synthesis. b. cell walls made of cellulose. c. uracil in their DNA. d. organelles for compartmentalization. e. mitochondria to generate ATP. What would be the valence number of electrons in the sulfur (S) atom? Its atomic number is 16. a. 2 b. 6 c. 8 d. 16 e. 32 All of the following are lipids except ______. a. cholesterol b. starch c. phospholipid d. wax e. triglyceride Which of the following is not an inoculating tool? a. Petri dish b. Loop c. Needle d. Pipette e. Swab The microorganisms that recycle nutrients by breaking down dead matter and wastes are called ______. a. decomposers b. prokaryotes c. pathogens d. eukaryotes e. fermenters Caring for patients infected with a new virus requires safety precautions for medical personnel. Choosing appropriate procedures is an example of a(n) ______ process. a. deductive b. inductive c. hypothetical d. pathogenic Microorganisms are best defined as organisms that a. cause human disease. b. lack a cell nucleus. c. are infectious particles. d. are too small to be seen with the unaided eye. e. can only be found growing in laboratories. Studies of the immune response to an infection caused by microorganisms would be performed by a(n) ______. a. hypersensitivity specialist b. epidemiologist c. immunologist d. geomicrobiologist Robert Koch and his colleagues first used agar in bacteriological media. Why was this ingredient an improvement on previous materials used to culture bacteria? a. Bacteria growing on the solidified medium did not degrade or break down the agar. b. Agar can convert from liquid to solid form, and back again, very easily. c. Agar was less expensive than the nutrients that Koch was previously using in the lab. d. Agar is a complete source of nutrients for most bacteria. An example of an amphipathic molecule found in living cells is ______. a. glucose b. phospholipid c. protein d. nucleic acid e. ATP A diagram of the three domains (Bacteria, Archaea, Eukarya) proceeding from the Last Universal Common Ancestor would show Archaea a. as the original cells from which the others derived. b. branching off the Domain Eukarya. c. branching off the Domain Bacteria. An atom has gained an electron; it has been ______. a. oxidized b. reduced c. ionized d. deionized e. neutralized Analysis of the small subunit rRNAs from all organisms in the three current domains suggests that a. the eukaryotes arose from prokaryotes. b. the Archaea are more closely related to bacteria than eukaryotes. c. all modern and extinct organisms on earth arose from a common ancestor. d. the prokarytoes, archaea, and eukaryotes are not related. Most biochemical macromolecules are polymers, which are chains of ______. a. hydrophobic molecules b. electrolytic molecules c. repeating monomers d. repeating carbohydrates e. hydrogen bonds A nutrient medium that contains at least one ingredient that is not chemically defined is termed ______. a. complex b. reducing c. enriched d. synthetic You are attempting to identify the type of helminth that has been isolated from a patient stool sample. The most important consideration to make this distinction is to a. look at the gross anatomy to determine if the body is segmented or not. b. ask the patient about recent food and water consumption. c. examine the sample to see if microscopic eggs are present. d. determine if the cells are eukaryotic or bacterial by looking for nuclei. Sterilizing filters have a pore size of 0.22 μm. Which of the following statements is true? a. Bacterial cells are typically between 1-10 μm and are blocked by the filter, whereas most viruses are between 20 and 200 nm and therefore pass through. b. Bacterial cells are typically between 1-10 nm and are blocked by the filter, whereas most viruses are between 20 and 200 μm and therefore pass through.